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Fina-finan graphite na Nanoscale (NGFs) kayan nano ne masu ƙarfi waɗanda za a iya samar da su ta hanyar adana tururin sinadarai masu guba, amma akwai tambayoyi game da sauƙin canja wurin su da kuma yadda yanayin saman yake shafar amfani da su a cikin na'urori masu zuwa. A nan mun bayar da rahoton girman NGF a ɓangarorin biyu na foil ɗin nickel na polycrystalline (yanki 55 cm2, kauri kusan 100 nm) da canja wurinsa mara polymer (gaba da baya, yanki har zuwa 6 cm2). Saboda yanayin foil ɗin mai kara kuzari, fina-finan carbon guda biyu sun bambanta a cikin halayensu na zahiri da sauran halaye (kamar ƙaiƙayin saman). Mun nuna cewa NGFs masu gefen baya mai kaifi sun dace sosai don gano NO2, yayin da NGFs masu santsi da kuma masu jurewa a gefen gaba (2000 S/cm, juriyar takarda - 50 ohms/m2) na iya zama masu jagoranci masu aiki. tashar ko electrode na tantanin halitta na hasken rana (tunda yana watsa 62% na hasken da ake gani). Gabaɗaya, hanyoyin girma da sufuri da aka bayyana na iya taimakawa wajen samar da NGF a matsayin madadin kayan carbon don aikace-aikacen fasaha inda fina-finan graphene da micron-thick graphite ba su dace ba.
Graphite abu ne da ake amfani da shi sosai a masana'antu. Abin lura shi ne, graphite yana da halaye na ƙarancin yawan taro da kuma yawan zafin jiki da wutar lantarki a cikin jirgin sama, kuma yana da ƙarfi sosai a cikin yanayi mai zafi da sinadarai masu tsanani1,2. Flake graphite sanannen abu ne da aka fara amfani da shi don binciken graphene3. Idan aka sarrafa shi zuwa siririn fim, ana iya amfani da shi a cikin aikace-aikace iri-iri, gami da na'urorin dumama zafi don na'urorin lantarki kamar wayoyin komai da ruwanka4,5,6,7, a matsayin abu mai aiki a cikin firikwensin8,9,10 da kuma don kariyar tsangwama ta lantarki11. 12 da fina-finai don lithography a cikin matsanancin ultraviolet13,14, gudanar da tashoshi a cikin ƙwayoyin hasken rana15,16. Ga duk waɗannan aikace-aikacen, zai zama babban fa'ida idan manyan wuraren fina-finan graphite (NGFs) tare da kauri da aka sarrafa a cikin sikelin nano <100 nm za a iya samar da su cikin sauƙi da jigilar su.
Ana samar da fina-finan Graphite ta hanyoyi daban-daban. A wani yanayi, an yi amfani da sakawa da faɗaɗawa sannan aka cire su don samar da flakes na Graphene10,11,17. Dole ne a ƙara sarrafa flakes ɗin zuwa fina-finai masu kauri da ake buƙata, kuma sau da yawa yana ɗaukar kwanaki da yawa don samar da zanen graphite mai kauri. Wata hanyar kuma ita ce farawa da abubuwan da za a iya amfani da su wajen ƙirƙirar graphite. A cikin masana'antu, ana haɗa zanen polymers da carbon (a 1000–1500 °C) sannan a haɗa shi da graphit (a 2800–3200 °C) don samar da kayan da aka tsara sosai. Duk da cewa ingancin waɗannan fina-finan yana da yawa, yawan amfani da makamashi yana da mahimmanci1,18,19 kuma mafi ƙarancin kauri yana iyakance ga microns 1,18,19,20.
Tacewar tururin sinadarai masu haifar da sinadarai (CVD) wata hanya ce da aka sani don samar da fina-finan graphene da ultra thin graphite (<10 nm) masu inganci da farashi mai ma'ana21,22,23,24,25,26,27. Duk da haka, idan aka kwatanta da girman fina-finan graphene da ultra thin graphite28, girman babban yanki da/ko amfani da NGF ta amfani da CVD ba a bincika shi sosai ba11,13,29,30,31,32,33.
Fina-finan graphene da graphite da aka girma a CVD sau da yawa suna buƙatar a canza su zuwa substrates masu aiki34. Waɗannan siraran canja wurin fim sun haɗa da manyan hanyoyi guda biyu35: (1) canja wurin da ba a yi amfani da shi ba36,37 da (2) canja wurin sinadarai masu ruwa da aka yi amfani da su ta hanyar etch (an tallafa wa substrate)14,34,38. Kowace hanya tana da wasu fa'idodi da rashin amfani kuma dole ne a zaɓi ta dangane da aikace-aikacen da aka yi niyya, kamar yadda aka bayyana a wani wuri35,39. Ga fina-finan graphene/graphite da aka girma a kan substrates masu catalytic, canja wurin ta hanyar hanyoyin sinadarai masu ruwa da ruwa (wanda polymethyl methacrylate (PMMA) shine Layer na tallafi da aka fi amfani da shi) ya kasance zaɓi na farko13,30,34,38,40,41,42. Kai da abokanka. An ambaci cewa ba a yi amfani da wani polymer don canja wurin NGF ba (girman samfurin kusan 4 cm2)25,43, amma ba a bayar da cikakkun bayanai game da kwanciyar hankali da/ko sarrafawa yayin canja wuri ba; Tsarin sunadarai masu laushi ta amfani da polymers ya ƙunshi matakai da dama, gami da amfani da kuma cire layin polymer na hadaya30,38,40,41,42. Wannan tsari yana da rashin amfani: misali, ragowar polymer na iya canza halayen fim ɗin da aka girma38. Ƙarin sarrafawa na iya cire ragowar polymer, amma waɗannan ƙarin matakan suna ƙara farashi da lokacin samar da fim38,40. A lokacin haɓakar CVD, ana ajiye Layer na graphene ba kawai a gefen gaba na foil ɗin mai kara kuzari ba (gefen da ke fuskantar kwararar tururi), har ma a gefen baya. Duk da haka, ana ɗaukar na ƙarshen a matsayin samfurin sharar gida kuma ana iya cire shi da sauri ta hanyar plasma mai laushi38,41. Sake amfani da wannan fim ɗin na iya taimakawa wajen haɓaka yawan amfanin ƙasa, koda kuwa yana da ƙarancin inganci fiye da fim ɗin carbon na fuska.
A nan, mun bayar da rahoton shirye-shiryen girman NGF mai girman wafer tare da ingancin tsari mai kyau akan foil ɗin nickel na polycrystalline ta CVD. An tantance yadda kauri na gaba da baya na foil ɗin ke shafar yanayin da tsarin NGF. Mun kuma nuna canja wurin NGF daga ɓangarorin biyu na foil ɗin nickel zuwa substrates masu aiki da yawa wanda ba shi da tsada kuma mara lahani ga muhalli kuma mun nuna yadda fina-finan gaba da baya suka dace da aikace-aikace daban-daban.
Sassan da ke ƙasa suna tattauna kauri daban-daban na fim ɗin graphite dangane da adadin layukan graphene da aka tara: (i) graphene mai layi ɗaya (SLG, Layer 1), (ii) graphene mai layi kaɗan (FLG, < Layer 10), (iii) graphene mai layi da yawa (MLG, Layer 10-30) da (iv) NGF (~ Layer 300). Na ƙarshen shine kauri mafi yawan da aka bayyana a matsayin kashi na yanki (kimanin kashi 97% na yanki a kowace 100 µm2)30. Shi ya sa ake kiran fim ɗin gaba ɗaya NGF kawai.
Fulin nickel na polycrystalline da ake amfani da su don haɗa fina-finan graphene da graphite suna da laushi daban-daban sakamakon ƙera su da kuma sarrafawa daga baya. Kwanan nan mun ba da rahoton wani bincike don inganta tsarin girma na NGF30. Mun nuna cewa sigogin tsari kamar lokacin annealing da matsin lamba na ɗaki a lokacin matakin girma suna taka muhimmiyar rawa wajen samun NGFs masu kauri iri ɗaya. A nan, mun ƙara bincika girman NGF akan saman gaba mai gogewa (FS) da kuma saman baya (BS) na nickel foil (Hoto na 1a). An duba nau'ikan samfura guda uku na FS da BS, waɗanda aka jera a cikin Tebur 1. Bayan dubawa ta gani, ana iya ganin girman NGF iri ɗaya a ɓangarorin biyu na nickel foil (NiAG) ta hanyar canjin launi na babban abun ciki na Ni daga launin toka na azurfa na ƙarfe zuwa launin toka mai matte (Hoto na 1a); an tabbatar da ma'aunin ƙananan ƙwayoyin cuta (Hoto na 1b, c). An lura da nau'in Raman na FS-NGF a yankin mai haske kuma an nuna shi ta hanyar kibiyoyi ja, shuɗi da orange a cikin Hoto na 1b a cikin Hoto na 1c. Kololuwar Raman ta musamman ta graphite G (1683 cm−1) da 2D (2696 cm−1) sun tabbatar da girman NGF mai lu'ulu'u sosai (Hoto na 1c, Tebur SI1). A cikin fim ɗin, an lura da rinjayen spectra na Raman tare da rabon ƙarfi (I2D/IG) ~0.3, yayin da ba a cika ganin spectra na Raman tare da I2D/IG = 0.8 ba. Rashin kololuwar da ba ta da kyau (D = 1350 cm-1) a cikin fim ɗin gaba ɗaya yana nuna ingancin girman NGF. An sami irin wannan sakamakon Raman akan samfurin BS-NGF (Hoto na SI1 a da b, Tebur SI1).
Kwatanta NiAG FS- da BS-NGF: (a) Hoton samfurin NGF (NiAG) na yau da kullun wanda ke nuna girman NGF a sikelin wafer (55 cm2) da samfuran foil na BS- da FS-Ni da aka samu, (b) Hotunan FS-NGF/Ni da aka samu ta hanyar na'urar hangen nesa, (c) spectra na Raman na yau da kullun da aka yi rikodin su a wurare daban-daban a cikin panel b, (d, f) Hotunan SEM a girma daban-daban akan FS-NGF/Ni, (e, g) Hotunan SEM a girma daban-daban Saiti BS -NGF/Ni. Kibiyar shuɗi tana nuna yankin FLG, kibiyar lemu tana nuna yankin MLG (kusa da yankin FLG), kibiyar ja tana nuna yankin NGF, kuma kibiyar magenta tana nuna ninkawa.
Tunda girma ya dogara ne akan kauri na farko, girman lu'ulu'u, yanayin, da iyakokin hatsi, cimma iko mai kyau na kauri na NGF akan manyan yankuna ya kasance ƙalubale20,34,44. Wannan binciken ya yi amfani da abubuwan da muka buga a baya30. Wannan tsari yana samar da yanki mai haske na 0.1 zuwa 3% a kowace 100 µm230. A cikin sassan da ke gaba, mun gabatar da sakamako ga nau'ikan yankuna biyu. Hotunan SEM masu girma suna nuna kasancewar wurare masu haske da yawa a ɓangarorin biyu (Hoto na 1f,g), suna nuna kasancewar yankunan FLG da MLG30,45. An kuma tabbatar da wannan ta hanyar watsawa na Raman (Hoto na 1c) da sakamakon TEM (wanda aka tattauna daga baya a cikin sashin "FS-NGF: tsari da kaddarorin"). Yankunan FLG da MLG da aka lura akan samfuran FS- da BS-NGF/Ni (NGF na gaba da baya da aka girma akan Ni) na iya girma akan manyan hatsi na Ni(111) da aka samar yayin kafin annashuwa22,30,45. An lura da naɗewa a ɓangarorin biyu (Hoto na 1b, wanda aka yiwa alama da kibiyoyi masu launin shunayya). Sau da yawa ana samun waɗannan naɗewa a cikin fina-finan graphene da graphite da aka girma a CVD saboda babban bambanci a cikin ma'aunin faɗaɗa zafi tsakanin graphite da substrate na nickel30,38.
Hoton AFM ya tabbatar da cewa samfurin FS-NGF ya fi na BS-NGF (Hoto na SI1) laushi (Hoto na SI2). Matsakaicin ƙimar kauri na tushen murabba'i (RMS) na FS-NGF/Ni (Hoto na SI2c) da BS-NGF/Ni (Hoto na SI2d) sune 82 da 200 nm, bi da bi (an auna su akan yanki na 20 × 20 μm2). Ana iya fahimtar mafi girman kauri bisa ga nazarin saman foil ɗin nickel (NiAR) a cikin yanayin da aka karɓa (Hoto na SI3). Hotunan SEM na FS da BS-NiAR an nuna su a cikin Hotunan SI3a–d, suna nuna yanayin saman daban-daban: foil ɗin FS-Ni mai gogewa yana da ƙwayoyin zagaye masu girman nano- da micron, yayin da foil ɗin BS-Ni mara gogewa yana nuna tsani na samarwa. a matsayin ƙwayoyin da ke da ƙarfi mai yawa. da raguwa. Hotunan ƙananan da manyan ƙuduri na foil ɗin nickel mai annealed (NiA) an nuna su a cikin Hoto na SI3e–h. A cikin waɗannan alkaluma, za mu iya lura da kasancewar ƙwayoyin nickel masu girman micron da yawa a ɓangarorin biyu na takardar nickel (Hoto na SI3e–h). Manyan hatsi na iya samun yanayin saman Ni(111), kamar yadda aka ruwaito a baya30,46. Akwai manyan bambance-bambance a cikin yanayin takardar nickel tsakanin FS-NiA da BS-NiA. Mafi girman kauri na BS-NGF/Ni ya faru ne saboda saman BS-NiAR mara gogewa, wanda samansa ya kasance mai kauri sosai ko da bayan an goge shi (Hoto na SI3). Wannan nau'in halayen saman kafin tsarin girma yana ba da damar sarrafa kauri na fim ɗin graphene da graphite. Ya kamata a lura cewa asalin substrate ya sami wasu sake tsara hatsi yayin girman graphene, wanda ya ɗan rage girman hatsi kuma ya ɗan ƙara kauri na saman substrate idan aka kwatanta da foil ɗin da aka cire da fim ɗin mai kaifi22.
Daidaita ƙaiƙayin saman substrate, lokacin annashuwa (girman hatsi)30,47 da kuma sarrafa sakin 43 zai taimaka wajen rage daidaiton kauri na NGF na yanki zuwa sikelin µm2 da/ko ma nm2 (watau, bambancin kauri na 'yan nanometers). Don sarrafa ƙaiƙayin saman substrate, ana iya la'akari da hanyoyin kamar goge electrolytic na foil nickel da ya haifar48. Sannan za a iya annashuwa da foil nickel da aka riga aka yi wa magani a ƙaramin zafin jiki (< 900 °C) 46 da lokaci (< min 5) don guje wa samuwar manyan hatsi na Ni(111) (wanda ke da amfani ga ci gaban FLG).
Graphene SLG da FLG ba za su iya jure matsin lamba na saman acid da ruwa ba, wanda ke buƙatar layukan tallafi na injiniya yayin ayyukan canja wurin sinadarai masu danshi22,34,38. Sabanin canja wurin sinadarai masu danshi na graphene38 mai layi ɗaya da aka tallafa wa polymer, mun gano cewa ɓangarorin biyu na NGF da aka girma ana iya canjawa ba tare da tallafin polymer ba, kamar yadda aka nuna a Hoto na 2a (duba Hoto na SI4a don ƙarin bayani). Canja wurin NGF zuwa wani abu da aka bayar yana farawa da rigar fim ɗin Ni30.49. An sanya samfuran NGF/Ni/NGF da aka girma cikin dare ɗaya a cikin 15 mL na 70% HNO3 da aka narkar da shi da 600 mL na ruwan deionized (DI). Bayan an narkar da foil ɗin Ni gaba ɗaya, FS-NGF ya kasance a kwance kuma yana iyo a saman ruwan, kamar samfurin NGF/Ni/NGF, yayin da aka nutsar da BS-NGF cikin ruwa (Hoto na 2a,b). Daga nan aka canja wurin NGF ɗin da aka ware daga wani beaker da ke ɗauke da ruwan da aka cire daga ion zuwa wani beaker sannan aka wanke NGF ɗin da aka ware sosai, ana maimaita shi sau huɗu zuwa shida ta cikin kwano mai siffar gilashi. A ƙarshe, an sanya FS-NGF da BS-NGF a kan abin da ake so (Hoto na 2c).
Tsarin canja wurin sinadarai mai laushi wanda ba shi da polymer don NGF da aka shuka akan foil na nickel: (a) Tsarin kwararar tsari (duba Hoto na SI4 don ƙarin bayani), (b) Hoton dijital na NGF da aka raba bayan an cire Ni (samfura 2), (c) Misali canja wurin FS - da BS-NGF zuwa substrate na SiO2/Si, (d) Canja wurin FS-NGF zuwa substrate na polymer mara haske, (e) BS-NGF daga samfurin iri ɗaya da panel d (an raba shi zuwa sassa biyu), an canza shi zuwa takarda C da aka yi wa ado da zinare da Nafion (substrate mai haske mai sassauƙa, gefuna masu alama da kusurwoyi ja).
Lura cewa canja wurin SLG da aka yi ta amfani da hanyoyin canja wurin sinadarai masu danshi yana buƙatar jimillar lokacin sarrafawa na awanni 20-24 38. Tare da dabarar canja wurin da ba ta da polymer da aka nuna a nan (Hoto na SI4a), jimlar lokacin sarrafa canja wurin NGF ya ragu sosai (kimanin awanni 15). Tsarin ya ƙunshi: (Mataki na 1) Shirya maganin etching kuma sanya samfurin a ciki (~ mintuna 10), sannan jira na dare don etching na Ni (~ mintuna 7200), (Mataki na 2) Kurkura da ruwan deionized (Mataki na 3). Ajiye a cikin ruwan deionized ko canja wurin zuwa substrate da aka nufa (minti 20). Ruwan da aka makale tsakanin NGF da babban matrix ana cire shi ta hanyar aikin capillary (ta amfani da takardar blotting)38, sannan a cire sauran ɗigon ruwa ta hanyar busarwa ta halitta (kimanin mintuna 30), kuma a ƙarshe an busar da samfurin na minti 10 a cikin tanda mai tsabta (10-1 mbar) a 50-90 °C (minti 60) 38.
An san Graphite yana jure wa ruwa da iska a yanayin zafi mai yawa (≥ 200 °C)50,51,52. Mun gwada samfurori ta amfani da Raman spectroscopy, SEM, da XRD bayan an adana su a cikin ruwan da aka cire a zafin ɗaki da kuma a cikin kwalaben da aka rufe na tsawon kwanaki kaɗan zuwa shekara guda (Hoto na SI4). Babu wani lalacewa da aka gani. Hoto na 2c yana nuna FS-NGF da BS-NGF masu tsayi a cikin ruwan da aka cire. Mun kama su a kan wani abu mai suna SiO2 (300 nm)/Si, kamar yadda aka nuna a farkon Hoto na 2c. Bugu da ƙari, kamar yadda aka nuna a Hoto na 2d,e, ana iya canja wurin NGF mai ci gaba zuwa wasu abubuwa kamar polymers (Thermabright polyamide daga Nexolve da Nafion) da takarda mai launin zinare. An sanya FS-NGF mai iyo cikin sauƙi akan abin da aka nufa (Hoto na 2c, d). Duk da haka, samfuran BS-NGF waɗanda suka fi girma fiye da 3 cm2 sun kasance da wahalar sarrafawa lokacin da aka nutsar da su gaba ɗaya a cikin ruwa. Yawanci, idan suka fara birgima a cikin ruwa, saboda rashin kulawa, wani lokacin sukan rabu gida biyu ko uku (Hoto na 2e). Gabaɗaya, mun sami damar cimma canja wurin PS- da BS-NGF ba tare da polymer ba (ci gaba da canja wurin ba tare da ci gaban NGF/Ni/NGF a 6 cm2) don samfuran har zuwa 6 da 3 cm2 a yanki, bi da bi. Duk wani babban ko ƙananan guntu da ya rage za a iya (a iya ganinsa cikin sauƙi a cikin maganin etching ko ruwan da aka cire ionized) akan abin da ake so (~1 mm2, Hoto na SI4b, duba samfurin da aka canja zuwa grid na jan ƙarfe kamar yadda yake a cikin "FS-NGF: Tsarin da Kadarorin (an tattauna) a ƙarƙashin "Tsarin da Kadarorin") ko adana don amfani a nan gaba (Hoto na SI4). Dangane da wannan ma'auni, mun kiyasta cewa za a iya dawo da NGF a cikin yawan amfanin ƙasa har zuwa 98-99% (bayan girma don canja wuri).
An yi nazarin samfuran canja wuri ba tare da polymer ba dalla-dalla. Halayen yanayin saman da aka samu akan FS- da BS-NGF/SiO2/Si (Hoto na 2c) ta amfani da hotunan na'urar hangen nesa (OM) da SEM (Hoto na SI5 da Hoto na 3) sun nuna cewa an canja waɗannan samfuran ba tare da na'urar hangen nesa ba. Lalacewar tsarin da ake gani kamar tsagewa, ramuka, ko wuraren da ba a naɗe ba. Naɗewar da ke kan girmawar NGF (Hoto na 3b, d, wanda aka yiwa alama da kibiyoyi masu launin shunayya) sun kasance ba tare da an canza su ba bayan an canza su. Dukansu FS- da BS-NGFs sun ƙunshi yankunan FLG (yankuna masu haske da kibiyoyi masu shuɗi suka nuna a Hoto na 3). Abin mamaki, sabanin yankuna kaɗan da suka lalace da aka saba gani yayin canja wurin polymer na fina-finan graphite masu siriri, an canja yankuna da yawa na FLG da MLG waɗanda ke haɗawa da NGF (wanda aka yiwa alama da kibiyoyi masu shuɗi a Hoto na 3d) ba tare da tsagewa ko karyewa ba (Hoto na 3d). 3). An ƙara tabbatar da ingancin injina ta amfani da hotunan TEM da SEM na NGF da aka canja zuwa grid ɗin jan ƙarfe mai lace-carbon, kamar yadda aka tattauna daga baya ("FS-NGF: Tsarin da Halaye"). BS-NGF/SiO2/Si da aka canja ya fi FS-NGF/SiO2/Si ƙarfi tare da ƙimar rms na 140 nm da 17 nm, bi da bi, kamar yadda aka nuna a Hoto na SI6a da b (20 × 20 μm2). Ƙimar RMS na NGF da aka canjawa zuwa substrate na SiO2/Si (RMS < 2 nm) ya yi ƙasa sosai (kusan sau 3) fiye da na NGF da aka girma akan Ni (Hoto na SI2), yana nuna cewa ƙarin tauri na iya dacewa da saman Ni. Bugu da ƙari, hotunan AFM da aka yi a gefunan samfuran FS- da BS-NGF/SiO2/Si sun nuna kauri na NGF na 100 da 80 nm, bi da bi (Hoto na SI7). Ƙaramin kauri na BS-NGF na iya zama sakamakon rashin fallasa saman kai tsaye ga iskar gas mai farawa.
An canza NGF (NiAG) ba tare da polymer akan SiO2/Si wafer ba (duba Hoto na 2c): (a,b) Hotunan SEM na FS-NGF da aka canza: ƙara girma da girma (daidai da murabba'in lemu a cikin panel). Yankuna na yau da kullun) - a). (c,d) Hotunan SEM na BS-NGF da aka canza: ƙara girma da girma (daidai da yankin da aka saba nunawa ta murabba'in lemu a cikin panel c). (e, f) Hotunan AFM na FS- da BS-NGF da aka canza. Kibiya shuɗi tana wakiltar yankin FLG - bambanci mai haske, kibiya cyan - bambanci mai duhu MLG, kibiya ja - bambanci mai duhu yana wakiltar yankin NGF, kibiya mai launin magenta tana wakiltar ninkawa.
An yi nazarin sinadaran FS- da BS-NGFs da aka girma da kuma aka canjawa wuri ta hanyar amfani da na'urar daukar hoto ta X-ray photoelectron spectroscopy (XPS) (Hoto na 4). An lura da wani rauni a cikin spectra da aka auna (Hoto na 4a, b), wanda ya yi daidai da Ni substrate (850 eV) na FS- da BS-NGFs da aka girma (NiAG). Babu kololuwa a cikin spectra da aka auna na FS- da BS-NGF/SiO2/Si da aka canjawa wuri (Hoto na 4c; ba a nuna sakamako makamancin haka na BS-NGF/SiO2/Si ba), yana nuna cewa babu gurɓataccen Ni bayan canja wuri. Hotuna na 4d–f sun nuna babban ƙudurin spectra na matakan kuzarin C 1 s, O 1 s da Si 2p na FS-NGF/SiO2/Si. Ƙarfin ɗaurewa na C 1 s na graphite shine 284.4 eV53.54. Siffar layi ta kololuwar graphite gabaɗaya ana ɗaukarta a matsayin rashin daidaituwa, kamar yadda aka nuna a Hoto na 4d54. Bakan C 1 s mai ƙuduri mai girma (Hoto na 4d) shi ma ya tabbatar da canja wurin tsarki (watau, babu ragowar polymer), wanda ya yi daidai da binciken da ya gabata38. Faɗin layi na bakan C 1 s na samfurin da aka girma (NiAG) da bayan canja wurin sune 0.55 da 0.62 eV, bi da bi. Waɗannan ƙimar sun fi na SLG (0.49 eV don SLG akan substrate SiO2)38. Duk da haka, waɗannan ƙimar sun fi ƙanƙanta fiye da faɗin layi da aka ruwaito a baya don samfuran graphene pyrolytic masu tsayi sosai (~0.75 eV)53,54,55, wanda ke nuna rashin wuraren carbon masu lahani a cikin kayan da ake amfani da su a yanzu. Bakan C 1 s da O 1 s suma ba su da kafadu, wanda ke kawar da buƙatar rage girman kololuwar ƙuduri mai girma54. Akwai kololuwar tauraron dan adam π → π* a kusa da 291.1 eV, wanda galibi ana lura da shi a cikin samfuran graphite. Siginar eV 103 eV da 532.5 eV a cikin Si 2p da O 1s core spectra (duba Hoto na 4e, f) an danganta su da substrate na SiO2 56, bi da bi. XPS dabara ce mai saurin amsawa ga saman, don haka ana ɗaukar siginar da ta dace da Ni da SiO2 da aka gano kafin da bayan canja wurin NGF, bi da bi, sun fito ne daga yankin FLG. An lura da irin wannan sakamako ga samfuran BS-NGF da aka canja (ba a nuna ba).
Sakamakon NiAG XPS: (ac) Binciken siginar nau'ikan abubuwan da ke cikin atomic na FS-NGF/Ni, BS-NGF/Ni da FS-NGF/SiO2/Si da aka canjawa wuri, bi da bi. (d–f) Babban siginar matakan tsakiya C 1s, O 1s da Si 2p na samfurin FS-NGF/SiO2/Si.
An tantance ingancin lu'ulu'u na NGF da aka canjawa wuri ta amfani da fasahar X-ray diffraction (XRD). Tsarin XRD na yau da kullun (Hoto na SI8) na FS- da BS-NGF/SiO2/Si da aka canjawa wuri suna nuna kasancewar kololuwar diffraction (0 0 0 2) da (0 0 0 4) a 26.6° da 54.7°, kama da graphite. . Wannan yana tabbatar da ingancin lu'ulu'u na NGF mai girma kuma ya yi daidai da nisan da ke tsakanin layukan d = 0.335 nm, wanda ake kiyayewa bayan matakin canjawa. Ƙarfin kololuwar diffraction (0 0 0 2) ya kai kusan sau 30 na kololuwar diffraction (0 0 0 4), yana nuna cewa jirgin lu'ulu'u na NGF ya daidaita da saman samfurin.
A bisa ga sakamakon SEM, Raman spectroscopy, XPS da XRD, an gano cewa ingancin BS-NGF/Ni iri ɗaya ne da na FS-NGF/Ni, kodayake ƙaiƙayin rms ɗinsa ya ɗan fi girma (Figures SI2, SI5) da SI7).
SLGs masu goyon bayan polymer har zuwa kauri 200 nm za su iya shawagi a kan ruwa. Ana amfani da wannan saitin a cikin hanyoyin canja wurin sinadarai masu ruwa da polymer. Graphene da graphite suna da hydrophobic (kusurwar rigar 80–90°) 57. An ruwaito cewa saman makamashi mai yuwuwa na graphene da FLG suna da faɗi sosai, tare da ƙarancin kuzari mai yuwuwa (~1 kJ/mol) don motsi na gefe na ruwa a saman58. Duk da haka, ƙididdigar kuzarin hulɗar ruwa tare da graphene da layuka uku na graphene suna da kusan − 13 da − 15 kJ/mol,58 bi da bi, yana nuna cewa hulɗar ruwa da NGF (kimanin layuka 300) ya yi ƙasa idan aka kwatanta da graphene. Wannan na iya zama ɗaya daga cikin dalilan da yasa NGF mai tsayi ya kasance a kwance a saman ruwa, yayin da graphene mai tsayi (wanda ke iyo a cikin ruwa) ya lanƙwasa ya lalace. Lokacin da aka nutsar da NGF gaba ɗaya cikin ruwa (sakamako iri ɗaya ne ga NGF mai tsauri da lebur), gefunansa suna lanƙwasa (Hoto na SI4). Idan aka nutse gaba ɗaya, ana sa ran makamashin hulɗar NGF-ruwa ya ninka kusan sau biyu (idan aka kwatanta da NGF mai iyo) kuma gefunan NGF sun naɗe don kiyaye kusurwar hulɗa mai girma (hydrophobicity). Mun yi imanin cewa za a iya haɓaka dabarun guje wa lanƙwasa gefunan NGF da aka haɗa. Hanya ɗaya ita ce amfani da gauraye masu narkewa don daidaita amsawar jikewar fim ɗin graphite59.
An riga an ruwaito cewa canja wurin SLG zuwa nau'ikan substrates daban-daban ta hanyar hanyoyin canja wurin sinadarai masu danshi. Gabaɗaya an yarda cewa ƙarfin van der Waals mai rauni yana wanzuwa tsakanin fina-finan graphene/graphite da substrates (ko dai substrates masu tauri kamar SiO2/Si38,41,46,60, SiC38, Au42, Si pillars22 da lacy carbon films30, 34 ko substrates masu sassauƙa kamar polyimide 37). A nan muna ɗauka cewa hulɗar nau'in iri ɗaya ta fi rinjaye. Ba mu lura da wata lalacewa ko ɓarkewar NGF ga kowane substrates da aka gabatar a nan yayin sarrafa injina ba (a lokacin siffantawa a ƙarƙashin yanayin iska da/ko yanayi ko lokacin ajiya) (misali, Hoto na 2, SI7 da SI9). Bugu da ƙari, ba mu lura da kololuwar SiC a cikin bakan XPS C 1 na matakin asali na samfurin NGF/SiO2/Si ba (Hoto na 4). Waɗannan sakamakon sun nuna cewa babu haɗin sinadarai tsakanin NGF da substrates da aka yi niyya.
A cikin sashin da ya gabata, "canja wurin FS- da BS-NGF mara polymer," mun nuna cewa NGF na iya girma da canja wurin a ɓangarorin biyu na foil ɗin nickel. Waɗannan FS-NGFs da BS-NGFs ba iri ɗaya ba ne dangane da ƙaiƙayin saman, wanda hakan ya sa muka bincika aikace-aikacen da suka fi dacewa ga kowane nau'in.
Idan aka yi la'akari da bayyanawa da kuma santsi na saman FS-NGF, mun yi nazarin tsarin gida, halayen gani da na lantarki dalla-dalla. Tsarin da tsarin FS-NGF ba tare da canja wurin polymer ba an siffanta su ta hanyar hoton microscopy na watsawa na lantarki (TEM) da kuma nazarin tsarin rarrabawa na yanki (SAED). Sakamakon da ya dace an nuna su a Hoto na 5. Hoto na TEM mai ƙarancin girma ya bayyana kasancewar yankunan NGF da FLG tare da halaye daban-daban na bambancin electron, watau wurare masu duhu da haske, bi da bi (Hoto na 5a). Fim ɗin gaba ɗaya yana nuna kyakkyawan daidaito na injiniya da kwanciyar hankali tsakanin yankuna daban-daban na NGF da FLG, tare da kyakkyawan haɗuwa kuma babu lalacewa ko tsagewa, wanda kuma aka tabbatar ta hanyar SEM (Hoto na 3) da nazarin TEM mai girma (Hoto na 5c-e). Musamman, a Hoto na 5d yana nuna tsarin gadar a babban ɓangarensa (matsayin da kibiya mai dige baƙi ta alama a Hoto na 5d), wanda aka siffanta shi da siffar triangle kuma ya ƙunshi layin graphene mai faɗin kusan 51. An ƙara rage abun da ke cikin tazara tsakanin 0.33 ± 0.01 nm zuwa layuka da yawa na graphene a yankin da ya fi kunkuntar (ƙarshen kibiyar baƙar fata mai ƙarfi a Hoto na 5 d).
Hoton TEM mai siffar planar na samfurin NiAG mara polymer akan grid na jan ƙarfe mai lacy: (a, b) Hotunan TEM masu ƙarancin girma gami da yankunan NGF da FLG, (ce) Hotunan girma masu girma na yankuna daban-daban a cikin panel-a da panel-b masu alama kibiyoyi ne masu launi ɗaya. Kibiyoyi kore a cikin panel a da c suna nuna wuraren da aka lalata a lokacin daidaita katako. (f–i) A cikin panel a zuwa c, ana nuna alamu na SAED a yankuna daban-daban ta hanyar shuɗi, cyan, orange, da da'irori ja, bi da bi.
Tsarin ribbon a cikin Hoto na 5c yana nuna (wanda aka yiwa alama da kibiya ja) yanayin tsaye na jiragen graphite, wanda wataƙila ya faru ne saboda samuwar nanofolds tare da fim ɗin (wanda aka saka a Hoto na 5c) saboda yawan matsin lamba na yankewa wanda ba a biya ba30,61,62. A ƙarƙashin babban ƙudurin TEM, waɗannan nanofolds 30 suna nuna yanayin kristal daban-daban fiye da sauran yankin NGF; jiragen ƙasa na layin graphite suna daidaitacce kusan a tsaye, maimakon a kwance kamar sauran fim ɗin (wanda aka saka a Hoto na 5c). Hakazalika, yankin FLG wani lokacin yana nuna lanƙwasa masu layi da kunkuntar kamar band (wanda aka yiwa alama da kibiyoyi masu shuɗi), waɗanda ke bayyana a ƙaramin girma da matsakaici a cikin Hoto na 5b, 5e, bi da bi. Shigarwa a cikin Hoto na 5e yana tabbatar da kasancewar layukan graphene mai layuka biyu da uku a cikin ɓangaren FLG (nisa tsakanin 0.33 ± 0.01 nm), wanda ya yi daidai da sakamakonmu na baya30. Bugu da ƙari, an nuna hotunan SEM da aka yi rikodin na NGF mara polymer da aka tura zuwa grid ɗin tagulla tare da fina-finan carbon mai laushi (bayan yin ma'aunin TEM na sama) a cikin Hoto na SI9. Yankin FLG da aka dakatar da shi sosai (wanda aka yiwa alama da kibiya shuɗi) da yankin da ya karye a Hoto na SI9f. An gabatar da kibiya shuɗi (a gefen NGF da aka canja) da gangan don nuna cewa yankin FLG zai iya tsayayya da tsarin canja wurin ba tare da polymer ba. A taƙaice, waɗannan hotunan sun tabbatar da cewa NGF da aka dakatar da shi kaɗan (gami da yankin FLG) yana kiyaye ingancin injiniya koda bayan an yi amfani da shi sosai da kuma fallasa shi ga babban injin yayin ma'aunin TEM da SEM (Hoto na SI9).
Saboda kyawun siffa ta NGF (duba Hoto na 5a), ba shi da wahala a daidaita flakes ɗin tare da axis ɗin yankin [0001] don nazarin tsarin SAED. Dangane da kauri na fim ɗin na gida da wurinsa, an gano yankuna da yawa masu ban sha'awa (maki 12) don nazarin bambance-bambancen electron. A cikin Hoto na 5a–c, an nuna huɗu daga cikin waɗannan yankuna na yau da kullun kuma an yi musu alama da da'irori masu launi (shuɗi, cyan, lemu, da ja mai lamba). Hoto na 2 da 3 don yanayin SAED. An samo hotuna 5f da g daga yankin FLG da aka nuna a Hoto na 5 da 5. Kamar yadda aka nuna a Hoto na 5b da c, bi da bi. Suna da tsarin hexagonal mai kama da graphene mai jujjuyawa 63. Musamman, Hoto na 5f yana nuna alamu uku da aka haɗa tare da yanayin iri ɗaya na axis ɗin yankin [0001], wanda aka juya da 10° da 20°, kamar yadda aka nuna ta hanyar rashin daidaiton kusurwa na nau'i uku na tunani (10-10). Hakazalika, Hoto na 5g yana nuna siffofi biyu masu tsayi da aka haɗa da hexagonal waɗanda aka juya da digiri 20. Rukunin siffofi biyu ko uku na hexagonal a yankin FLG na iya tasowa daga layuka uku na graphene a cikin jirgin sama ko a waje da jirgin sama waɗanda aka juya dangane da juna. Sabanin haka, siffofin rarraba wutar lantarki a cikin Hoto na 5h,i (wanda ya yi daidai da yankin NGF da aka nuna a Hoto na 5a) suna nuna tsari ɗaya [0001] tare da babban ƙarfin rarrabawa mai ma'ana, wanda ya yi daidai da kauri mafi girma na abu. Waɗannan samfuran SAED sun dace da tsarin zane mai kauri da matsakaicin daidaitawa fiye da FLG, kamar yadda aka hasashe daga ma'aunin 64. Halayen halayen kristal na NGF ya nuna kasancewar lu'ulu'u biyu ko uku masu tsayi da aka haɗa da graphite (ko graphene). Abin da ya fi muhimmanci a yankin FLG shine cewa lu'ulu'u suna da wani matakin rashin daidaituwa a cikin jirgin sama ko a waje da jirgin sama. An riga an ruwaito barbashi/layers na graphite waɗanda ke da kusurwoyin juyawa a cikin jirgin sama na 17°, 22° da 25° ga NGF da aka shuka akan fina-finan Ni 64. Ƙimar kusurwar juyawa da aka lura a cikin wannan binciken sun yi daidai da kusurwoyin juyawa da aka lura a baya (±1°) don graphene mai jujjuyawa na BLG63.
An auna halayen wutar lantarki na NGF/SiO2/Si a 300 K a kan wani yanki na 10×3 mm2. Ƙimar yawan mai ɗaukar electron, motsi da kuma ikon amfani da electron sune 1.6 × 1020 cm-3, 220 cm2 V-1 C-1 da 2000 S-cm-1, bi da bi. Ƙimar motsi da ikon amfani da electron namu suna kama da graphite na halitta2 kuma sun fi pyrolytic graphite mai saurin canzawa (wanda aka samar a 3000 °C)29. Ƙimar yawan mai ɗaukar electron da aka lura sun fi girma fiye da waɗanda aka ruwaito kwanan nan (7.25 × 10 cm-3) don fina-finan graphite masu kauri na micron waɗanda aka shirya ta amfani da zanen polyimide mai zafi (3200 °C) 20.
Mun kuma yi ma'aunin watsawa da aka gani ta hanyar UV akan FS-NGF da aka canja zuwa substrates na quartz (Hoto na 6). Sakamakon bakan ya nuna kusan watsawa mai 62% a cikin kewayon 350-800 nm, yana nuna cewa NGF yana da haske ga haske mai gani. A zahiri, ana iya ganin sunan "KAUST" a cikin hoton dijital na samfurin a cikin Hoto na 6b. Kodayake tsarin nanocrystalline na NGF ya bambanta da na SLG, ana iya kimanta adadin yadudduka kusan ta amfani da ƙa'idar asarar watsawa 2.3% a kowace ƙarin Layer 65. Dangane da wannan alaƙar, adadin yadudduka na graphene tare da asarar watsawa 38% shine 21. NGF da aka girma galibi ya ƙunshi yadudduka graphene 300, watau kusan kauri 100 nm (Hoto na 1, SI5 da SI7). Saboda haka, muna ɗauka cewa bayyanar gani da aka lura ta dace da yankunan FLG da MLG, tunda an rarraba su a cikin fim ɗin (Hoto na 1, 3, 5 da 6c). Baya ga bayanan tsarin da ke sama, watsawa da bayyana gaskiya suma suna tabbatar da ingancin lu'ulu'u na NGF da aka canjawa wuri.
(a) Ma'aunin watsawa da aka gani ta hanyar UV, (b) canja wurin NGF na yau da kullun akan quartz ta amfani da samfurin wakilci. (c) Tsarin NGF (akwatin duhu) tare da yankuna FLG da MLG da aka rarraba daidai gwargwado waɗanda aka yiwa alama a matsayin siffofi masu launin toka bazuwar a cikin samfurin (duba Hoto na 1) (kimanin yanki 0.1–3% a kowace 100 μm2). Siffofin bazuwar da girmansu a cikin zane don dalilai ne na misali kawai kuma ba su dace da ainihin yankuna ba.
An riga an canja wurin NGF mai haske wanda CVD ya noma zuwa saman silicon mara komai kuma ana amfani da shi a cikin ƙwayoyin hasken rana15,16. Ingancin canza wutar lantarki da aka samu (PCE) shine 1.5%. Waɗannan NGFs suna yin ayyuka da yawa kamar yadudduka masu aiki, hanyoyin jigilar caji, da electrodes masu haske15,16. Duk da haka, fim ɗin graphite ba iri ɗaya bane. Ana buƙatar ƙarin haɓakawa ta hanyar sarrafa juriyar takarda da watsa haske na electrode graphite a hankali, tunda waɗannan kaddarorin guda biyu suna taka muhimmiyar rawa wajen tantance ƙimar PCE na ƙwayar hasken rana15,16. Yawanci, fina-finan graphene suna da haske 97.7% zuwa haske mai gani, amma suna da juriyar takarda na 200-3000 ohms/sq.16. Ana iya rage juriyar saman fina-finan graphene ta hanyar ƙara yawan yadudduka (canja wurin yadudduka da yawa na graphene) da kuma yin doping tare da HNO3 (~30 Ohm/sq.)66. Duk da haka, wannan tsari yana ɗaukar lokaci mai tsawo kuma layukan canja wuri daban-daban ba koyaushe suke kula da kyakkyawar hulɗa ba. NGF ɗinmu na gaba yana da halaye kamar ƙarfin lantarki 2000 S/cm, juriya ga takardar fim 50 ohm/sq. da kuma bayyanannen haske 62%, wanda hakan ya sa ya zama madadin hanyoyin watsawa ko na'urorin lantarki masu ƙarfi a cikin ƙwayoyin hasken rana15,16.
Duk da cewa tsarin da kuma sinadaran saman BS-NGF sun yi kama da FS-NGF, amma rashin kyawunsa ya bambanta ("Ci gaban FS- da BS-NGF"). A da, mun yi amfani da fim ɗin graphite22 mai siriri sosai a matsayin na'urar firikwensin iskar gas. Saboda haka, mun gwada yuwuwar amfani da BS-NGF don ayyukan gano iskar gas (Hoto na SI10). Da farko, an canja sassan BS-NGF masu girman mm2 zuwa guntu mai auna wutar lantarki (Hoto na SI10a-c). An bayar da rahoton cikakkun bayanai game da kera guntu a baya; yankin da ke da saurin aiki shine 9 mm267. A cikin hotunan SEM (Hoto na SI10b da c), wutar lantarki ta zinariya a bayyane take ta hanyar NGF. Kuma, za a iya ganin cewa an cimma daidaiton rufe guntu ga duk samfuran. An yi rikodin ma'aunin na'urorin firikwensin iskar gas daban-daban (Hoto na SI10d) (Hoto na SI11) kuma an nuna ƙimar amsawar da aka samu a cikin Hoto na SI10g. Wataƙila tare da wasu iskar gas masu katsewa ciki har da SO2 (200 ppm), H2 (2%), CH4 (200 ppm), CO2 (2%), H2S (200 ppm) da NH3 (200 ppm). Ɗaya daga cikin dalilan da ke iya haifar da hakan shine yanayin lantarki na NO2. Lokacin da aka shaƙa a saman graphene, yana rage shaƙar lantarki ta hanyar tsarin. An gabatar da kwatancen bayanan lokacin amsawa na firikwensin BS-NGF tare da firikwensin da aka buga a baya a cikin Tebur SI2. Hanyar sake kunna firikwensin NGF ta amfani da plasma UV, plasma O3 ko thermal (50–150°C) na samfuran da aka fallasa yana ci gaba, mafi kyau a bi shi da aiwatar da tsarin da aka haɗa69.
A lokacin aikin CVD, girman graphene yana faruwa a ɓangarorin biyu na substrate mai kara kuzari41. Duk da haka, yawanci ana fitar da BS-graphene yayin aikin canja wurin41. A cikin wannan binciken, mun nuna cewa ana iya samun ingantaccen girma na NGF da canja wurin NGF mara polymer a ɓangarorin biyu na tallafin mai kara kuzari. BS-NGF ya fi siriri (~80 nm) fiye da FS-NGF (~100 nm), kuma wannan bambanci an bayyana shi ta hanyar gaskiyar cewa BS-Ni ba a fallasa shi kai tsaye ga kwararar iskar gas mai kara kuzari ba. Mun kuma gano cewa rashin kyawun substrate na NiAR yana shafar rashin kyawun NGF. Waɗannan sakamakon sun nuna cewa ana iya amfani da FS-NGF mai girma a matsayin kayan da aka riga aka yi amfani da su don graphene (ta hanyar cirewa70) ko kuma a matsayin tashar sarrafawa a cikin ƙwayoyin rana15,16. Sabanin haka, za a yi amfani da BS-NGF don gano iskar gas (Hoto na SI9) kuma wataƙila don tsarin adana makamashi71,72 inda rashin kyawun saman sa zai zama da amfani.
Idan aka yi la'akari da abin da ke sama, yana da amfani a haɗa aikin da ake yi a yanzu da fina-finan graphite da aka buga a baya waɗanda CVD ya noma da kuma amfani da foil na nickel. Kamar yadda za a iya gani a Jadawali na 2, matsin lamba mafi girma da muka yi amfani da shi ya rage lokacin amsawa (matakin girma) ko da a yanayin zafi mai ƙarancin gaske (a cikin kewayon 850–1300 °C). Mun kuma sami ci gaba mafi girma fiye da yadda aka saba, wanda ke nuna yuwuwar faɗaɗawa. Akwai wasu abubuwan da za a yi la'akari da su, waɗanda muka haɗa wasu daga cikinsu a cikin teburin.
An noma NGF mai inganci mai gefe biyu akan foil ɗin nickel ta hanyar amfani da CVD mai catalytic. Ta hanyar kawar da substrates na polymer na gargajiya (kamar waɗanda ake amfani da su a cikin CVD graphene), muna samun canja wurin NGF mai tsabta da mara lahani (wanda aka girma a bayan da gaba na foil ɗin nickel) zuwa nau'ikan substrates masu mahimmanci na tsari. Abin lura, NGF ya haɗa da yankuna na FLG da MLG (yawanci 0.1% zuwa 3% a kowace 100 µm2) waɗanda aka haɗa su sosai cikin fim ɗin mai kauri. TEM mai siffar planar ya nuna cewa waɗannan yankuna sun ƙunshi tarin barbashi na graphite/graphene guda biyu zuwa uku (lu'ulu'u ko yadudduka, bi da bi), wasu daga cikinsu suna da rashin daidaiton juyawa na 10-20°. Yankunan FLG da MLG suna da alhakin bayyanawar FS-NGF zuwa haske da ake iya gani. Dangane da zanen baya, ana iya ɗaukar su a layi ɗaya da zanen gaba kuma, kamar yadda aka nuna, suna iya samun manufa mai aiki (misali, don gano iskar gas). Waɗannan nazarin suna da matukar amfani don rage sharar gida da farashi a cikin matakan CVD na masana'antu.
Gabaɗaya, matsakaicin kauri na CVD NGF yana tsakanin zanen graphene (ƙananan da kuma layuka da yawa) da kuma zanen graphite na masana'antu (micrometer). Jerin abubuwan da suka ban sha'awa, tare da hanyar da muka ƙirƙira don samarwa da jigilar su, ya sa waɗannan fina-finan sun dace musamman don aikace-aikacen da ke buƙatar aikin amsawar graphite, ba tare da kashe kuɗin ayyukan samar da masana'antu masu amfani da makamashi ba a halin yanzu.
An sanya foil ɗin nickel mai kauri 25-μm (tsarki 99.5%, Goodfellow) a cikin na'urar CVD ta kasuwanci (Aixtron BMPro mai inci 4). An tsaftace tsarin da argon sannan aka kwashe shi zuwa matsin lamba na tushe na 10-3 mbar. Sannan an sanya foil ɗin nickel. a cikin Ar/H2 (Bayan an riga an rufe foil ɗin Ni na tsawon minti 5, foil ɗin ya fuskanci matsin lamba na 500 mbar a 900 °C. An sanya NGF a cikin kwararar CH4/H2 (100 cm3 kowanne) na tsawon minti 5. Daga nan aka sanya samfurin zuwa zafin jiki ƙasa da 700 °C ta amfani da kwararar Ar (4000 cm3) a 40 °C/min. An bayyana cikakkun bayanai game da inganta tsarin girma na NGF a wani wuri30.
An yi amfani da SEM wajen ganin yanayin saman samfurin ta amfani da na'urar hangen nesa ta Zeiss Merlin (1 kV, 50 pA). An auna ƙaiƙayin saman samfurin da kauri na NGF ta amfani da AFM (Dimension Icon SPM, Bruker). An yi ma'aunin TEM da SAED ta amfani da na'urar hangen nesa ta FEI Titan 80–300 Cubed microscope wacce aka sanye da bindiga mai haske (300 kV), na'urar hangen nesa ta FEI Wien da kuma na'urar hangen nesa ta CEOS don samun sakamakon ƙarshe. ƙudurin sarari 0.09 nm. An canza samfuran NGF zuwa grids na jan ƙarfe mai rufi da carbon don ɗaukar hoton TEM mai faɗi da nazarin tsarin SAED. Don haka, yawancin samfuran suna rataye a cikin ramukan membrane mai tallafi. An yi nazarin samfuran NGF da aka canja ta hanyar XRD. An samo tsarin diffraction na X-ray ta amfani da na'urar auna foda (Brucker, mai canza yanayin D2 tare da tushen Cu Kα, mai gano 1.5418 Å da mai gano LYNXEYE) ta amfani da tushen radiation na Cu tare da diamita na tabo na 3 mm.
An yi rikodin ma'aunin maki na Raman da yawa ta amfani da na'urar hangen nesa mai haɗaka (Alpha 300 RA, WITEC). An yi amfani da na'urar hangen nesa mai girman 532 nm tare da ƙarancin ƙarfin motsawa (25%) don guje wa tasirin da zafin jiki ke haifarwa. An yi amfani da na'urar hangen nesa ta X-ray photoelectron spectroscopy (XPS) akan na'urar hangen nesa ta Kratos Axis Ultra a kan samfurin yanki na 300 × 700 μm2 ta amfani da hasken Al Kα monochromatic (hν = 1486.6 eV) a ƙarfin 150 W. An sami na'urar hangen nesa mai ƙuduri a kuzarin watsawa na 160 eV da 20 eV, bi da bi. An yanke samfuran NGF da aka canjawa zuwa SiO2 guda (3 × 10 mm2 kowanne) ta amfani da na'urar hangen nesa ta PLS6MW (1.06 μm) ytterbium fiber laser a 30 W. An ƙera ma'aunin waya ta tagulla (kauri 50 μm) ta amfani da manne na azurfa a ƙarƙashin na'urar hangen nesa. An gudanar da gwaje-gwajen jigilar lantarki da tasirin Hall akan waɗannan samfuran a 300 K da kuma bambancin filin maganadisu na ± 9 Tesla a cikin tsarin auna halayen jiki (PPMS EverCool-II, Quantum Design, Amurka). An yi rikodin spectra na UV-vis da aka watsa ta amfani da na'urar auna haske ta Lambda 950 UV-vis a cikin kewayon NGF 350-800 nm wanda aka canja zuwa substrates na quartz da samfuran ma'aunin quartz.
An haɗa na'urar firikwensin juriyar sinadarai (guntun lantarki mai haɗa lambobi) zuwa allon da'ira na musamman 73 kuma an cire juriyar na ɗan lokaci. An haɗa allon da'ira na bugawa wanda na'urar take a kai da tashoshin hulɗa kuma an sanya shi a cikin ɗakin na'urar firikwensin gas 74. An ɗauki ma'aunin juriya a ƙarfin lantarki na 1 V tare da ci gaba da duba daga tsaftacewa zuwa fallasa iskar gas sannan aka sake sharewa. Da farko an tsaftace ɗakin ta hanyar tsarkakewa da nitrogen a 200 cm3 na tsawon awa 1 don tabbatar da cire duk sauran masu nazarin da ke cikin ɗakin, gami da danshi. Daga nan aka saki masu nazarin a hankali cikin ɗakin a daidai wannan ƙimar kwararar 200 cm3 ta hanyar rufe silinda N2.
An buga wani sabon sigar wannan labarin kuma ana iya samunsa ta hanyar hanyar haɗin da ke saman labarin.
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Cheng KY, Brown PW da Cahill DG Rarraba zafin fim ɗin graphite da aka girma a kan Ni (111) ta hanyar ajiyar tururin sinadarai mai ƙarancin zafin jiki. Karin magana. Matt. Interface 3, 16 (2016).
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