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Mafirimu eNanoscale graphite (NGFs) imhando dzakasimba dze nanomaterials dzinogona kugadzirwa ne catalytic chemical vapor deposition, asi mibvunzo ichiripo nezvekureruka kwadzo kutamiswa uye kuti surface morphology inokanganisa sei kushandiswa kwadzo mumidziyo inotevera. Pano tinotaura nezvekukura kweNGF kumativi ese e polycrystalline nickel foil (nzvimbo 55 cm2, ukobvu hunenge 100 nm) uye transfer yayo isina polymer (kumberi nekumashure, nzvimbo inosvika 6 cm2). Nekuda kwe morphology ye catalyst foil, mafirimu maviri ekabhoni akasiyana muhunhu hwawo hwepanyama uye humwe hunhu (senge surface roughness). Tinoratidza kuti maNGF ane rougher backside akakodzera kuonekwa kweNO2, nepo maNGF akapfava uye anotungamira mberi (2000 S/cm, sheet resistance - 50 ohms/m2) anogona kuva ma conductor anoshanda. channel kana electrode ye solar cell (sezvo ichitumira 62% yechiedza chinoonekwa). Zvose zviri zviviri, kukura kwakatsanangurwa uye maitiro ekutakura anogona kubatsira kuita kuti NGF ive imwe nzira yekushandisa kabhoni mukushandiswa kwetekinoroji uko mafirimu egraphene negrafiti ane ukobvu hwe micron asina kukodzera.
Graphite chinhu chinoshandiswa zvakanyanya mumaindasitiri. Zvinonyanya kukosha kuti graphite ine hunhu hwehuremu hwakaderera uye ine thermal ne electrical conductivity yakakwira, uye yakagadzikana munzvimbo dzine kupisa kwakanyanya uye makemikari1,2. Flake graphite chinhu chinotangira graphene research3. Kana ikagadziriswa kuita mafilm matete, inogona kushandiswa mumhando dzakasiyana siyana, kusanganisira heat sinks dzezvishandiso zvemagetsi zvakaita semafoni4,5,6,7, sechinhu chinoshanda mumasensa8,9,10 uye chekudzivirira kupindira kwemagetsi11.12 uye mafirimu e lithography mu ultraviolet yakanyanya13,14, ichiitisa machaneli mumasero ezuva15,16. Kune ese maapplication aya, zvingave zvakanaka kana nzvimbo huru dzemafilm egraphite (NGFs) ane ukobvu hwakadzorwa mu nanoscale <100 nm dzikagona kugadzirwa uye kutakurwa zviri nyore.
Mafirimu eGraphite anogadzirwa nenzira dzakasiyana-siyana. Mune imwe nyaya, kupinza nekuwedzera zvichiteverwa nekubviswa kwemafuta kwakashandiswa kugadzira ma graphene flakes10,11,17. Maflakes acho anofanira kugadziriswazve kuita mafirimu ane ukobvu hunodiwa, uye kazhinji zvinotora mazuva akati wandei kugadzira ma dense graphite sheets. Imwe nzira ndeyekutanga nema graphitable solid precursors. Muindasitiri, ma polymers anoiswa carbonized (pa 1000–1500 °C) uye ozoiswa graphitized (pa 2800–3200 °C) kuti agadzire zvinhu zvakagadzirwa zvakanaka. Kunyangwe mhando yemafirimu aya yakakwira, simba rinoshandiswa rakakosha1,18,19 uye ukobvu hushoma hunogumira kuma microns mashoma1,18,19,20.
Catalytic chemical vapor deposition (CVD) inzira inozivikanwa yekugadzira mafirimu egraphene ne ultrathin graphite (<10 nm) ane hunhu hwepamusoro uye mutengo unonzwisisika21,22,23,24,25,26,27. Zvisinei, kana tichienzanisa nekukura kwemafirimu egraphene ne ultrathin graphite28, kukura kwenzvimbo yakakura uye/kana kushandiswa kweNGF uchishandisa CVD hakunyanyi kuongororwa11,13,29,30,31,32,33.
Mafirimu egraphene negrafiti akakurirwa neCVD anowanzo fanirwa kutamisirwa kune substrates dzinoshanda34. Aya mafirimi matete anosanganisira nzira mbiri huru35: (1) kutamisirwa kusina etch36,37 uye (2) kutamisirwa kwemakemikari emvura akavakirwa pa etch (substrate inotsigirwa)14,34,38. Nzira yega yega ine zvakanakira nezvayakaipira uye inofanira kusarudzwa zvichienderana nekushandiswa kwainofanira kuitwa, sezvakatsanangurwa kune dzimwe nzvimbo35,39. Kune mafirimu egraphene/grafiti akakurirwa pa substrates dzinobatsira, kutamisirwa kuburikidza nemaitiro emakemikari akanyorova (ayo polymethyl methacrylate (PMMA) ndiyo inonyanya kushandiswa) inoramba iri sarudzo yekutanga13,30,34,38,40,41,42. Iwe nevamwe. Zvakataurwa kuti hapana polymer yakashandiswa kutamisirwa kweNGF (sample size inenge 4 cm2)25,43, asi hapana ruzivo rwakapihwa maererano nekugadzikana kwesample uye/kana kubata panguva yekutamisirwa; Maitiro emakemikari emvura achishandisa mapolymer ane matanho akati wandei, anosanganisira kushandiswa uye kubviswa kwechikamu chepolymer chinobayirwa30,38,40,41,42. Maitiro aya ane zvazvakaipira: semuenzaniso, ma polymer residues anogona kushandura hunhu hwefirimu yakakura38. Kugadziriswa kwakawedzerwa kunogona kubvisa ma residual polymer, asi matanho aya ekuwedzera anowedzera mutengo nenguva yekugadzira firimu38,40. Munguva yekukura kweCVD, graphene layer inoiswa kwete chete kumberi kwe catalyst foil (rutivi rwakatarisana nekuyerera kwemhepo), asiwo kuseri kwayo. Zvisinei, yekupedzisira inoonekwa semarara uye inogona kubviswa nekukurumidza ne soft plasma38,41. Kudzokorodza firimu iyi kunogona kubatsira kuwedzera goho, kunyangwe iri yemhando yakaderera pane face carbon film.
Pano, tinoshuma nezvekugadzirwa kwekukura kweNGF kwemhando mbiri dzewafer-scale ine chimiro chepamusoro pa polycrystalline nickel foil neCVD. Zvakaongororwa kuti kuomarara kwepamberi nepashure pefoil kunokanganisa sei chimiro nechimiro cheNGF. Tinoratidzawo kutamiswa kweNGF kubva kumativi ese enickel foil kusingadhuri uye kusina zvakatipoteredza kwepolymer-isina polymer kubva kumativi ese enickel foil kuenda kuma substrates akawanda uye tinoratidza kuti mafirimu epamberi nepashure akakodzera sei kushandiswa kwakasiyana-siyana.
Zvikamu zvinotevera zvinokurukura ukobvu hwakasiyana hwemafirimu egraphite zvichienderana nehuwandu hwemachira egraphene akaunganidzwa: (i) graphene imwe chete (SLG, 1 layer), (ii) graphene shoma (FLG, < 10 layers), (iii) graphene yakawanda (MLG, 10-30 layers) uye (iv) NGF (~300 layers). Iyo yekupedzisira ndiyo ukobvu hunowanzo ratidzwa sechikamu chenzvimbo (inenge 97% nzvimbo pa 100 µm2)30. Ndosaka firimu rese richingonzi NGF.
Mafoiri enickel ePolycrystalline anoshandiswa pakugadzira magraphene nemagraphite ane magadzirirwo akasiyana nekuda kwekugadzirwa kwawo uye kugadziriswa kwakatevera. Munguva pfupi yapfuura takashuma chidzidzo chekuvandudza maitiro ekukura kweNGF30. Tinoratidza kuti ma process parameter akadai se annealing time uye chamber pressure panguva yekukura zvinoita basa rakakosha mukuwana maNGF ane ukobvu hwakafanana. Pano, takaongorora zvakare kukura kweNGF pamusoro pe polished front (FS) uye unpolished back (BS) ye nickel foil (Mufananidzo 1a). Mhando nhatu dzemasampuru FS neBS dzakaongororwa, dzakanyorwa muTafura 1. Pakutarisa nemaziso, kukura kwakafanana kweNGF kumativi ese e nickel foil (NiAG) kunogona kuonekwa nekuchinja kweruvara rwe bulk Ni substrate kubva pa simbi yesirivha grey kusvika pa matte grey (Mufananidzo 1a); zviyero zve microscopic zvakasimbiswa (Mufananidzo 1b, c). Raman spectrum yakajairika yeFS-NGF yakaonekwa munzvimbo yakajeka uye inoratidzwa nemiseve tsvuku, bhuruu neorenji muMufananidzo 1b inoratidzwa muMufananidzo 1c. MaRaman peaks egraphite G (1683 cm−1) uye 2D (2696 cm−1) anosimbisa kukura kweNGF ine crystalline yakanyanya (Mufananidzo 1c, Tafura SI1). Mufirimu rese, huwandu hwakawanda hweRaman spectra ine intensity ratio (I2D/IG) ~0.3 hwakaonekwa, nepo Raman spectra ine I2D/IG = 0.8 isingawanzoonekwa. Kusavapo kwema peaks asina kunaka (D = 1350 cm-1) mufirimu rese kunoratidza mhando yepamusoro yekukura kweNGF. Mhedzisiro yakafanana yeRaman yakawanikwa paBS-NGF sample (Mufananidzo SI1 a na b, Tafura SI1).
Kuenzanisa kweNiAG FS- neBS-NGF: (a) Mufananidzo wemuenzaniso weNGF (NiAG) unoratidza kukura kweNGF pachiyero chewafer (55 cm2) uye sampuli dzeBS- neFS-Ni foil dzinobuda, (b) Mifananidzo yeFS-NGF/Ni yakawanikwa nemaikorosikopu yemaziso, (c) maspectra eRaman akajairika akanyorwa panzvimbo dzakasiyana mupaneru b, (d, f) Mifananidzo yeSEM pakukura kwakasiyana paFS-NGF/Ni, (e, g) Mifananidzo yeSEM pakukura kwakasiyana Sets BS -NGF/Ni. Museve webhuruu unoratidza nharaunda yeFLG, museve weorenji unoratidza nharaunda yeMLG (pedyo nenharaunda yeFLG), museve mutsvuku unoratidza nharaunda yeNGF, uye museve wemagenta unoratidza kupeta.
Sezvo kukura kuchienderana nekukora kwechikamu chekutanga, saizi yekristaro, kurongeka, uye miganhu yetsanga, kuwana kudzora kwakaringana kweukobvu hweNGF munzvimbo dzakakura kuchiri dambudziko20,34,44. Chidzidzo ichi chakashandisa zvatakamboburitsa30. Maitiro aya anogadzira nzvimbo yakajeka ye0.1 kusvika 3% pa100 µm230. Muzvikamu zvinotevera, tinopa mhedzisiro yemarudzi ese ari maviri enzvimbo. Mifananidzo yeSEM yakakura inoratidza kuvapo kwenzvimbo dzakasiyana-siyana dzakapenya kumativi ese (Mufananidzo 1f, g), zvichiratidza kuvapo kwenzvimbo dzeFLG neMLG30,45. Izvi zvakasimbiswawo neRaman scattering (Mufananidzo 1c) uye TEM results (yakakurukurwa gare gare muchikamu "FS-NGF: chimiro uye hunhu"). Nzvimbo dzeFLG neMLG dzakaonekwa paFS- neBS-NGF/Ni samples (mberi nekumashure NGF yakadyarwa paNi) dzinogona kunge dzakakura patsanga hombe dzeNi(111) dzakaumbwa panguva yepre-annealing22,30,45. Kupeta kwakaonekwa kumativi ese (Mufananidzo 1b, wakanyorwa nemiseve yepepuru). Mapeta aya anowanzo kuwanikwa mumafirimu egraphene negraphite akakurirwa neCVD nekuda kwemusiyano mukuru mu coefficient of thermal expansion pakati pegraphite ne nickel substrate30,38.
Mufananidzo weAFM wakasimbisa kuti sampuro yeFS-NGF yakanga yakati sandara kupfuura sampuro yeBS-NGF (Mufananidzo SI1) (Mufananidzo SI2). Root mean square (RMS) roughness values yeFS-NGF/Ni (Mufananidzo SI2c) uye BS-NGF/Ni (Mufananidzo SI2d) i82 ne200 nm, zvichiteerana (yakayerwa pamusoro penzvimbo ye20 × 20 μm2). roughness yakakwira inogona kunzwisiswa zvichibva pakuongororwa kwepamusoro kwenickel (NiAR) foil mumamiriro akagamuchirwa (Mufananidzo SI3). Mifananidzo yeSEM yeFS neBS-NiAR inoratidzwa muMifananidzo SI3a–d, ichiratidza mamiriro akasiyana epamusoro: polished FS-Ni foil ine nano- uye micron-spherical particles, nepo unpolished BS-Ni foil inoratidza ladder yekugadzira. sezvikamu zvine simba guru. uye kudzikira. Mifananidzo yakaderera uye yakakwirira ye annealed nickel foil (NiA) inoratidzwa muMufananidzo SI3e–h. Mumifananidzo iyi, tinogona kuona kuvapo kwezvikamu zvakasiyana-siyana zve nickel pamativi ese ari maviri e nickel foil (Mufananidzo SI3e–h). Zviyo zvikuru zvinogona kunge zvine Ni(111) surface orientation, sezvakambotaurwa30,46. Pane musiyano mukuru mu nickel foil morphology pakati peFS-NiA neBS-NiA. Kuomarara kwakanyanya kweBS-NGF/Ni kunokonzerwa nepamusoro peBS-NiAR isina kuporishwa, iyo pamusoro payo inoramba yakaomarara kunyangwe mushure mekunamirwa (Mufananidzo SI3). Rudzi urwu rwekutsanangurwa kwepamusoro pechinhu chisati chakura kunoita kuti roughness ye graphene ne graphite films idzorwe. Zvinofanira kucherechedzwa kuti substrate yekutanga yakagadziriswazve panguva yekukura kwe graphene, izvo zvakaderedza zvishoma saizi ye grain uye zvakawedzera roughness yepamusoro pe substrate zvichienzaniswa ne annealed foil ne catalyst film22.
Kugadzirisa kuomarara kwenzvimbo ye substrate, nguva yekunamira (saizi yetsanga)30,47 uye release control43 zvichabatsira kuderedza kufanana kweukobvu hweNGF munzvimbo kusvika pa µm2 uye/kana kunyange nm2 scale (kureva, kusiyana kweukobvu hwema nanometers mashoma). Kudzora kuomarara kwenzvimbo ye substrate, nzira dzakadai sekupolisha kwe electrolytic ye nickel foil inobuda dzinogona kufungwa nezvadzo48. Nickel foil yakagadziriswa kare inogona kunamirwa patembiricha yakaderera (< 900 °C)46 uye nguva (< 5 min) kudzivirira kuumbwa kweNi(111) hombe tsanga (izvo zvinobatsira kukura kweFLG).
Graphene yeSLG neFLG haigone kutsungirira kushushikana kwemvura neacids, zvichida ma layers ekutsigira michina panguva yekuchinjisa makemikari akanyorova22,34,38. Kusiyana nekuchinjisa makemikari akanyorova kwe polymer-supported single-layer graphene38, takaona kuti mativi ese eNGF akakura anogona kutamiswa pasina rutsigiro rwe polymer, sezvakaratidzwa muMufananidzo 2a (ona Mufananidzo SI4a kuti uwane rumwe ruzivo). Kuchinjisa NGF kune substrate yakapihwa kunotanga nekunyorova kwefirimu reNi30.49 riri pasi. Samples dzeNGF/Ni/NGF dzakakura dzakaiswa husiku hwese mu15 mL ye70% HNO3 yakasanganiswa ne600 mL yemvura yakanyungudutswa (DI). Mushure mekunge Ni foil yanyungudutswa zvachose, FS-NGF inoramba yakati sandara uye inoyangarara pamusoro pemvura, kungofanana nesampuli yeNGF/Ni/NGF, nepo BS-NGF ichinyudzwa mumvura (Mufananidzo 2a,b). NGF yakaparadzaniswa yakazobva yatamiswa kubva mubeaker rimwe raiva nemvura yakachena yakabviswa maion kuenda kune rimwe beaker uye NGF yakaparadzaniswa yakasukwa zvakanaka, ichidzokororwa ka4 kusvika katanhatu kuburikidza nedhishi regirazi rakakombama. Pakupedzisira, FS-NGF neBS-NGF zvakaiswa panzvimbo yaidiwa (Mufananidzo 2c).
Maitiro ekutamisa makemikari emvura asina polymer eNGF akakurira pa nickel foil: (a) Dhayagiramu yekuyerera kwemaitiro (ona Mufananidzo SI4 kuti uwane rumwe ruzivo), (b) Mufananidzo wedhijitari weNGF yakaparadzaniswa mushure mekuchekwa kweNi (sampuli mbiri), (c) Muenzaniso wekutamisa FS - uye BS-NGF kuenda kuSiO2/Si substrate, (d) kutamisa FS-NGF kuenda kupurasitiki yepolymer isina kupenya, (e) BS-NGF kubva kumuenzaniso mumwe chete nepaneru d (yakakamurwa kuita zvikamu zviviri), yakatamiswa kuenda kupepa reC rakafukidzwa negoridhe uye Nafion (substrate inochinjika yakajeka, mipendero yakanyorwa nemakona matsvuku).
Ziva kuti kutamiswa kweSLG kunoitwa uchishandisa nzira dzekutamiswa kwemakemikari emvura kunoda nguva yese yekugadzirisa yemaawa 20-24. Nehunyanzvi hwekutamiswa kwepolymer-free hunoratidzwa pano (Mufananidzo SI4a), nguva yese yekugadzirisa kutamiswa kweNGF yakaderedzwa zvakanyanya (anenge maawa gumi nemashanu). Maitiro acho anosanganisira: (Danho 1) Gadzira mhinduro yekucheka woisa sample mairi (~maminitsi gumi), wobva wamirira husiku hwese kuti Ni etching (~maminitsi mazana manomwe nemakumi maviri), (Danho 2) Shamba nemvura yakabviswa (Danho - 3). chengeta mumvura yakabviswa kana kutamiswa kune chinangwa substrate (maminitsi makumi maviri). Mvura yakavharirwa pakati peNGF ne bulk matrix inobviswa ne capillary action (uchishandisa blotting paper)38, ipapo madonhwe emvura asara anobviswa nekuomeswa kwechisikigo (anenge maminitsi makumi matatu), uye pakupedzisira sample inoomeswa kwemaminitsi gumi mu vacuum oven (10-1 mbar) pa50-90 °C (maminitsi makumi matanhatu)38.
Graphite inozivikanwa kuti inotsungirira kuvapo kwemvura nemhepo pakupisa kwakanyanya (≥ 200 °C)50,51,52. Takaedza samples tichishandisa Raman spectroscopy, SEM, uye XRD mushure mekuchengetwa mumvura yakabviswa ion patembiricha yemumba uye mumabhodhoro akavharwa kwemazuva mashoma kusvika pagore (Mufananidzo SI4). Hapana kuora kunoonekwa. Mufananidzo 2c unoratidza FS-NGF neBS-NGF dzakazvimiririra mumvura yakabviswa ion. Takazvitora paSiO2 (300 nm)/Si substrate, sezvakaratidzwa pakutanga kweMufananidzo 2c. Pamusoro pezvo, sezvakaratidzwa muMufananidzo 2d,e, NGF inoenderera mberi inogona kutamisirwa kune substrates dzakasiyana-siyana dzakadai sepolymers (Thermabright polyamide kubva kuNexolve neNafion) uye carbon paper yakaputirwa negoridhe. FS-NGF inoyangarara yakaiswa nyore nyore pa substrate yakanangwa (Mufananidzo 2c, d). Zvisinei, samples dzeBS-NGF dzakakura kupfuura 3 cm2 dzaive dzakaoma kubata kana dzakanyudzwa mumvura zvachose. Kazhinji, kana zvatanga kuumburuka mumvura, nekuda kwekubata zvisina hanya dzimwe nguva zvinopatsanurwa kuita zvikamu zviviri kana zvitatu (Mufananidzo 2e). Zvose, takakwanisa kuwana kutamiswa kwePS- neBS-NGF pasina polymer (kutamiswa kunoramba kuripo pasina kukura kweNGF/Ni/NGF pa6 cm2) kwemasampuli anosvika 6 ne3 cm2 munzvimbo, zvichiteerana. Chero zvidimbu zvikuru kana zvidiki zvasara zvinogona (kuonekwa zviri nyore mumushonga wekucheka kana mvura yakabviswa ion) pane substrate inodiwa (~1 mm2, Mufananidzo SI4b, ona muenzaniso wakatamisirwa kugridi yemhangura sezviri mu "FS-NGF: Maumbirwo neZvinhu (zvakakurukurwa) pasi pe "Maumbirwo neZvinhu") kana kuchengetwa kuti zvishandiswe mune ramangwana (Mufananidzo SI4). Zvichibva pane izvi, tinofungidzira kuti NGF inogona kudzoserwa muzvibereko zvinosvika 98-99% (mushure mekukura kwekutamisirwa).
Sampuli dzekutapurirana dzisina polymer dzakaongororwa zvakadzama. Hunhu hwepamusoro hwechimiro hwakawanikwa paFS- neBS-NGF/SiO2/Si (Mufananidzo 2c) uchishandisa optical microscopy (OM) nemifananidzo yeSEM (Mufananidzo SI5 neMufananidzo 3) zvakaratidza kuti sampuro idzi dzakatapurirwa pasina microscopy. Kukuvara kwechimiro kunoonekwa senge mitswe, maburi, kana nzvimbo dzakavhurwa. Mapete ari paNGF iri kukura (Mufananidzo 3b, d, akanyorwa nemiseve yepepuru) akaramba aripo mushure mekutapurirwa. MaFS- neBS-NGF ese ari maviri anoumbwa nenzvimbo dzeFLG (nzvimbo dzakajeka dzinoratidzwa nemiseve yebhuruu muMufananidzo 3). Zvinoshamisa kuti, kusiyana nenzvimbo shoma dzakakuvara dzinowanzoonekwa panguva yekutapurirwa kwepolymer kwemafirimu egraphite akatetepa, nzvimbo dzinoverengeka dzeFLG neMLG dzine saizi ye micron dzakabatana neNGF (dzakanyorwa nemiseve yebhuruu muMufananidzo 3d) dzakatapurirwa pasina mitswe kana kuputsika (Mufananidzo 3d). 3). Kusimba kwemuchina kwakasimbiswazve uchishandisa mifananidzo yeTEM neSEM yeNGF yakaendeswa kumagridi emhangura elace-carbon, sezvakakurukurwa gare gare (“FS-NGF: Maumbirwo uye Zvimiro”). BS-NGF/SiO2/Si yakafambiswa yakakombama kupfuura FS-NGF/SiO2/Si ine rms values ye140 nm uye 17 nm, zvichiteerana, sezvakaratidzwa muMufananidzo SI6a na b (20 × 20 μm2). Kukosha kweRMS kweNGF kwakaendeswa kuSiO2/Si substrate (RMS < 2 nm) kwakaderera zvakanyanya (kanenge katatu) kupfuura kweNGF yakakurira paNi (Mufananidzo SI2), zvichiratidza kuti kuomarara kwakawedzerwa kunogona kuenderana neNi surface. Pamusoro pezvo, mifananidzo yeAFM yakaitwa pamucheto weFS- neBS-NGF/SiO2/Si samples yakaratidza ukobvu hweNGF hwe100 ne80 nm, zvichiteerana (Mufananidzo SI7). Ukobvu hudiki hweBS-NGF hunogona kunge huri mugumisiro wekuti pamusoro pacho hapasati pave pachena zvakananga kugasi rinotangira.
NGF (NiAG) yakachinjirwa isina polymer paSiO2/Si wafer (ona Mufananidzo 2c): (a,b) Mifananidzo yeSEM yeFS-NGF yakachinjirwa: kukura kwakaderera uye kwakakwirira (kunoenderana nesquare yeorenji iri mupaneru). Nzvimbo dzakajairika) – a). (c,d) Mifananidzo yeSEM yeBS-NGF yakachinjirwa: kukura kwakaderera uye kwakakwirira (kunoenderana nenzvimbo yakajairika inoratidzwa nesquare yeorenji mupaneru c). (e, f) Mifananidzo yeAFM yeFS- neBS-NGF dzakachinjirwa. Museve webhuruu unomiririra dunhu reFLG – kusiyana kwakajeka, museve wecyan – kusiyana kweMLG nhema, museve mutsvuku – kusiyana kwakasviba kunomiririra dunhu reNGF, museve wemagenta unomiririra kupeta.
Kuumbwa kwemakemikari eFS- neBS-NGF dzakakura nedzakapfuudzwa kwakaongororwa neX-ray photoelectron spectroscopy (XPS) (Mufananidzo 4). Kureba kusina kusimba kwakaonekwa mumaspectra akayerwa (Mufananidzo 4a, b), zvinoenderana neNi substrate (850 eV) yeFS- neBS-NGF dzakakura (NiAG). Hapana kukwirira mumaspectra akayerwa eFS- neBS-NGF/SiO2/Si (Mufananidzo 4c; mhedzisiro yakafanana yeBS-NGF/SiO2/Si hairatidzwe), zvichiratidza kuti hapana kusvibiswa kweNi kwasara mushure mekupfuudzwa. Mifananidzo 4d–f inoratidza maspectra epamusoro-soro eC1 s, O1 s uye Si 2p energy levels yeFS-NGF/SiO2/Si. Simba rekubatanidza reC1 s yegraphite i284.4 eV53.54. Chimiro chemutsetse wepamusoro pegraphite chinowanzoonekwa sechisina kuenzana, sezvakaratidzwa muMufananidzo 4d54. Iyo high-resolution core-level C1 s spectrum (Mufananidzo 4d) yakasimbisawo kufambiswa kwakachena (kureva, hapana ma polymer residues), izvo zvinoenderana nezvidzidzo zvekare38. Upamhi hwemutsara weC1 s spectra yemuenzaniso mutsva (NiAG) uye mushure mekutamiswa ndeye 0.55 uye 0.62 eV, zvichiteerana. Aya mavalues akakwira kupfuura ayo eSLG (0.49 eV yeSLG pane substrate yeSiO2)38. Zvisinei, aya mavalues madiki pane linewidths dzakambotaurwa dze high-oriented pyrolytic graphene samples (~0.75 eV)53,54,55, zvichiratidza kusavapo kwenzvimbo dzakakanganisika dzekabhoni mune zviripo. Ma spectra eC1 s neO1 s ground level haanawo mafudzi, zvichibvisa kudiwa kwe high-resolution peak deconvolution54. Pane π → π* satellite peak inenge 291.1 eV, iyo inowanzoonekwa mu graphite samples. Ma signals e103 eV ne 532.5 eV ari mu core level spectra yeSi 2p neO1 s (ona Mufananidzo 4e, f) anokonzerwa neSiO2 56 substrate, zvichiteerana. XPS inzira inonyatsonzwa pamusoro, saka ma signals anoenderana neNi neSiO2 akaonekwa asati atumirwa NGF uye mushure mekutamiswa, zvichiteerana, anofungidzirwa kuti anobva kuFLG region. Mhedzisiro yakafanana yakaonekwa kune ma sampuli eBS-NGF akatamiswa (haana kuratidzwa).
Zvakabuda muNiAG XPS: (ac) Ongorora maspectra akasiyana emaatomu eFS-NGF/Ni, BS-NGF/Ni uye akatamiswa FS-NGF/SiO2/Si, zvichiteerana. (d–f) Maspectra epamusoro-soro emazinga epakati C 1 s, O 1s uye Si 2p yeFS-NGF/SiO2/Si sample.
Hunhu hwese hwemakristaro eNGF akatamiswa hwakaongororwa uchishandisa X-ray diffraction (XRD). Mapatani eXRD akajairika (Mufananidzo SI8) eFS- neBS-NGF/SiO2/Si akatamiswa anoratidza kuvapo kwezvikamu zve diffraction (0 0 0 2) uye (0 0 0 4) pa26.6° ne54.7°, zvakafanana negraphite. . Izvi zvinosimbisa hunhu hwepamusoro hwe NGF uye zvinoenderana ne interlayer distance ye d = 0.335 nm, iyo inochengetwa mushure medanho rekutamiswa. Simba re diffraction peak (0 0 0 2) rinopetwa ka30 kupfuura diffraction peak (0 0 0 4), zvichiratidza kuti NGF crystal plane yakanyatsoenderana ne sample surface.
Zvichienderana nemhedzisiro yeSEM, Raman spectroscopy, XPS neXRD, mhando yeBS-NGF/Ni yakawanikwa yakafanana neyeFS-NGF/Ni, kunyangwe kuomarara kwayo kwerms kwakakwira zvishoma (Mifananidzo SI2, SI5) uye SI7).
MaSLG ane ma polymer support layers anosvika 200 nm ukobvu anogona kukwakuka pamusoro pemvura. Iyi setup inowanzo shandiswa mu polymer-assisted wet chemical transfer processes22,38. Graphene ne graphite hazvina hydrophobic (wet angle 80–90°) 57. Nzvimbo dzine simba dzinokwanisa kushandiswa dze graphene ne FLG dzakanzi dzakati sandara, dzine simba shoma (~1 kJ/mol) rekufamba kwemvura padivi pemvura pamusoro58. Zvisinei, simba rekubatana kwemvura rakaverengerwa ne graphene nema layers matatu e graphene anenge ari −13 uye −15 kJ/mol,58 zvichiteerana, zvichiratidza kuti kudyidzana kwemvura ne NGF (anenge 300 layers) kwakaderera zvichienzaniswa ne graphene. Ichi chingave chimwe chezvikonzero nei freestanding NGF ichiramba yakatambarara pamusoro pemvura, nepo freestanding graphene (iyo inokwakuka mumvura) inokotama uye inoputsika. Kana NGF yanyura mumvura zvachose (mhedzisiro yacho yakafanana kune rough uye flat NGF), mipendero yayo inokotama (Mufananidzo SI4). Kana mvura yanyura mumvura zvachose, zvinotarisirwa kuti simba rekubatana kwemvura neNGF rinenge rakapetwa kaviri (zvichienzaniswa neNGF inoyangarara) uye kuti mipendero yeNGF inopetwa kuti irambe yakabata angle yakakwira (hydrophobicity). Tinotenda kuti nzira dzinogona kugadzirwa kudzivirira kupetwa kwemipendero yeNGF dzakaiswa mumvura. Imwe nzira ndeyekushandisa mixed solvents kugadzirisa wetting reaction yegraphite film59.
Kutamiswa kweSLG kuenda kumarudzi akasiyana-siyana esubstrates kuburikidza nemaitiro ekutamiswa kwemakemikari emvura kwakambotaurwa. Kazhinji zvinogamuchirwa kuti simba revan der Waals risina simba riripo pakati pemafirimu egraphene/graphite nesubstrates (ingava substrates dzakasimba dzakadai seSiO2/Si38,41,46,60, SiC38, Au42, Si pillars22 uye lacy carbon films30, 34 kana substrates dzinochinjika dzakadai sepolyimide 37). Pano tinofunga kuti kudyidzana kwerudzi rumwe chete ndiko kunonyanya kukosha. Hatina kuona kukuvara kana kukweshwa kweNGF kune chero substrates dzakaratidzwa pano panguva yekubata kwemuchina (panguva yekutsanangurwa pasi pevacuum uye/kana mamiriro ekunze kana panguva yekuchengetwa) (semuenzaniso, Mufananidzo 2, SI7 uye SI9). Pamusoro pezvo, hatina kuona SiC peak muXPS C1 s spectrum yepakati peiyo NGF/SiO2/Si sample (Mufananidzo 4). Mhedzisiro iyi inoratidza kuti hapana chisungo chemakemikari pakati peNGF nesubstrate yakatarwa.
Muchikamu chakapfuura, "Kutamiswa kweFS- neBS-NGF kusina polymer," takaratidza kuti NGF inogona kukura uye kutamiswa kumativi ese e nickel foil. Aya maFS-NGF neBS-NGF haana kufanana maererano nekuoma kwenzvimbo, izvo zvakatikurudzira kuti tiongorore mashandisirwo akakodzera emhando yega yega.
Tichifunga nezvekujeka uye pamusoro payo pakapfava, takadzidza chimiro chayo chemuno, maitiro e optical uye emagetsi zvakadzama. Chimiro uye chimiro cheFS-NGF isina polymer transfer zvakaratidzwa ne transmission electron microscopy (TEM) imaging uye selected area electron diffraction (SAED) pattern analysis. Mhedzisiro inoenderana inoratidzwa muMufananidzo 5. Kukura kwakaderera kwe TEM imaging kwakaratidza kuvapo kwenzvimbo dzeNGF neFLG dzine hunhu hwakasiyana hwe electron contrast, kureva nzvimbo dzakasviba uye dzakapenya, zvichiteerana (Mufananidzo 5a). Firimu rese rinoratidza kunaka kwe mechanical integrity uye kugadzikana pakati penzvimbo dzakasiyana dzeNGF neFLG, nekubatana kwakanaka uye pasina kukuvara kana kubvaruka, izvo zvakasimbiswawo neSEM (Mufananidzo 3) uye zvidzidzo zve TEM zvekuwedzera (Mufananidzo 5c-e). Kunyanya, muMufananidzo 5d inoratidza chimiro chebhiriji pachikamu chayo chikuru (nzvimbo yakaratidzwa nemuseve mutema une madotsi muMufananidzo 5d), iyo inoratidzwa nechimiro chetriangular uye ine graphene layer ine upamhi hweinenge 51. Muumbirwo une spacing yepakati pe 0.33 ± 0.01 nm unoderedzwazve kuita zvidimbu zvakasiyana zve graphene munzvimbo yakamanikana (kumagumo kwemuseve mutema wakasimba uri paMufananidzo 5 d).
Mufananidzo wePlanar TEM wemuenzaniso weNiAG usina polymer pagridi yemhangura ine carbon lacy: (a, b) Mifananidzo yeTEM ine kukura kushoma inosanganisira nzvimbo dzeNGF neFLG, (ce) Mifananidzo ine kukura kushoma yenzvimbo dzakasiyana mupanera-a nepanera-b miseve yakanyorwa ine ruvara rwakafanana. Miseve yegirini mupanera a na c inoratidza nzvimbo dzakatenderera dzekukuvadzwa panguva yekurongeka kwemuti. (f–i) Mupanera a kusvika c, mapatani eSAED munzvimbo dzakasiyana anoratidzwa nedenderedzwa rebhuruu, cyan, orenji, uye dzvuku, zvichiteerana.
Maumbirwo eribhoni ari muMufananidzo 5c anoratidza (akanyorwa nemuseve mutsvuku) kurongeka kwakatwasuka kwegirafiti lattice planes, izvo zvinogona kunge zvichikonzerwa nekuumbwa kwenanofolds dziri mufirimu (inset muMufananidzo 5c) nekuda kwekuwedzerwa kwekushomeka kweshear stress30,61,62. Pasi peTEM ine resolution yepamusoro, aya nanofolds 30 anoratidza kurongeka kwakasiyana kwekristaro pane mamwe matunhu eNGF; matunhu epasi pegirafiti lattice akatarisana akatwasuka, pane kuti akatwasuka semamwe mativi efirimu (inset muMufananidzo 5c). Saizvozvowo, dunhu reFLG dzimwe nguva rinoratidza mafolds akafanana nemabhandi akamanikana (akanyorwa nemiseve yebhuruu), ayo anoonekwa pakukura kwakaderera uye kwepakati muMifananidzo 5b, 5e, zvichiteerana. Inset muMufananidzo 5e inosimbisa kuvapo kwezvikamu zviviri nezvikamu zvitatu zvegirafiti muchikamu cheFLG (interplanar distance 0.33 ± 0.01 nm), izvo zvinoenderana zvakanaka nemigumisiro yedu yapfuura30. Pamusoro pezvo, mifananidzo yeSEM yakarekodhwa yeNGF isina polymer yakaendeswa kumagrid emhangura ine mafirimu elacy carbon (mushure mekuita zviyero zveTEM zvepamusoro) inoratidzwa muMufananidzo SI9. Dunhu reFLG rakarekodhwa zvakanaka (rakanyorwa nemuseve webhuruu) nenzvimbo yakatyoka muMufananidzo SI9f. Museve webhuruu (pamucheto weNGF yakatamisirwa) unoratidzwa nemaune kuratidza kuti dunhu reFLG rinogona kuramba maitiro ekutamisa pasina polymer. Mukupfupisa, mifananidzo iyi inosimbisa kuti NGF yakarekodhwa zvishoma (kusanganisira dunhu reFLG) inochengetedza hunhu hwemakanika kunyangwe mushure mekubata kwakasimba uye kuratidzwa kune vacuum yakakwira panguva yekuyerwa kweTEM neSEM (Mufananidzo SI9).
Nekuda kwekuti NGF yakatsetseka zvakanaka (ona Mufananidzo 5a), hazvina kuoma kutenderedza maflakes ari padivi pe [0001] domain axis kuti uongorore chimiro cheSAED. Zvichienderana nehukobvu hwefirimu nenzvimbo yaro, nzvimbo dzinoverengeka dzinofadza (12 points) dzakaonekwa kuti dziongororwe electron diffraction studies. MuMifananidzo 5a–c, nzvimbo ina idzi dzakajairika dzinoratidzwa uye dzakanyorwa nemadenderedzwa ane mavara (bhuruu, cyan, orenji, uye tsvuku dzakanyorwa). Mifananidzo 2 ne3 yeSAED mode. Mifananidzo 5f na g yakawanikwa kubva munzvimbo yeFLG inoratidzwa muMifananidzo 5 ne5. Sezvakaratidzwa muMifananidzo 5b na c, zvichiteerana. Ane chimiro chehexagonal chakafanana negraphene yakatsveyama63. Kunyanya, Mufananidzo 5f unoratidza mapatani matatu ane mafambiro akafanana e [0001] zone axis, akatenderedzwa ne10° na20°, sezvinoratidzwa nekusawirirana kwemakona kwemapaya matatu e (10-10) reflections. Saizvozvowo, Mufananidzo 5g unoratidza mapatani maviri ane hexagonal akatenderedzwa ne20°. Mapoka maviri kana matatu emapatani ane hexagonal munzvimbo yeFLG anogona kubva muzvikamu zvitatu zve graphene zviri mukati kana kunze kweplane 33 zvakatenderedzwa zvichienderana. Kusiyana neizvi, mapatani e diffraction e electron ari muMufananidzo 5h, i (anoenderana nenzvimbo yeNGF inoratidzwa muMufananidzo 5a) anoratidza patani imwe chete [0001] ine simba re diffraction repamusoro, rinoenderana nehukuru hwezvinhu. Aya ma SAED models anoenderana nechimiro che graphitic chakakora uye kurongeka kwepakati pane FLG, sezvakafungidzirwa kubva mu index 64. Kutsanangurwa kwehunhu hwe crystalline yeNGF kwakaratidza kuvapo kwemakristaro maviri kana matatu ane superimposed graphite (kana graphene). Chinonyanya kukosha munharaunda yeFLG ndechekuti makristaro ane mwero wakati we in-plane kana out-of-plane misoritation. Zvidimbu zveGraphite/zvikamu zvine makona ekutenderera ari mukati me17°, 22° uye 25° zvakambotaurwa nezveNGF yakadyarwa pamafirimu eNi 64. Makonero ekutenderera akaonekwa muchidzidzo ichi anoenderana nemakona ekutenderera akamboonekwa (±1°) eBLG63 graphene yakamonyoroka.
Hunhu hwemagetsi hweNGF/SiO2/Si hwakayerwa pa300 K pamusoro penzvimbo ye10×3 mm2. Hunhu hwehuwandu hwemagetsi anotakura maerekitironi, kufamba uye kufambisa magetsi i1.6 × 1020 cm-3, 220 cm2 V-1 C-1 uye 2000 S-cm-1, zvichiteerana. Hunhu hwemagetsi nekufambisa magetsi hweNGF yedu hwakafanana negraphite2 yechisikigo uye hwakakwira kupfuura graphite yepyrolytic inowanikwa mumusika (inogadzirwa pa3000 °C)29. Hunhu hwemagetsi anotakura magetsi hwakaonekwa hwakakwirira kaviri kupfuura hwakataurwa munguva pfupi yapfuura (7.25 × 10 cm-3) yemafirimu egraphite ane ganda rakakora re micron akagadzirwa achishandisa mapepa epolyimide ane tembiricha yakakwira (3200 °C) 20.
Takaitawo zviyero zveUV-visible transmittance paFS-NGF yakaendeswa kune quartz substrates (Mufananidzo 6). Spectramu inobuda inoratidza transmittance inenge yakafanana ye62% iri pakati pe350–800 nm, zvichiratidza kuti NGF inopenya kuchiedza chinoonekwa. Kutaura zvazviri, zita rekuti "KAUST" rinogona kuonekwa mumufananidzo wedhijitari wemuenzaniso uri muMufananidzo 6b. Kunyangwe chimiro chenanocrystalline cheNGF chakasiyana necheSLG, huwandu hwezvikamu hunogona kufungidzirwa uchishandisa mutemo wekurasikirwa kwe2.3% transmission pakuwedzera layer65. Zvichienderana nehukama uhwu, huwandu hwezvikamu zvegraphene zvine kurasikirwa kwe38% transmission i21. NGF yakakura inonyanya kuve nezvikamu zvegraphene mazana matatu, kureva kuti anenge 100 nm ukobvu (Mufananidzo 1, SI5 naSI7). Nokudaro, tinofunga kuti kupenya kwemaziso kwakaonekwa kunoenderana nenzvimbo dzeFLG neMLG, sezvo dzakapararira mufirimu rese (Mifananidzo 1, 3, 5 na6c). Pamusoro pedata remaumbirwo ari pamusoro apa, kufambiswa kwemhepo uye kujeka zvinosimbisawo mhando yepamusoro yekristalline yeNGF yakapfuudzwa.
(a) Kuyerwa kweUV-visible transmittance, (b) kufambiswa kweNGF kwakajairika pa quartz uchishandisa muenzaniso unomiririra. (c) Schematic yeNGF (bhokisi rerima) ine nzvimbo dzakagoverwa zvakaenzana dzeFLG neMLG dzakanyorwa semaumbirwo egrey random mumuenzaniso wese (ona Mufananidzo 1) (inenge 0.1–3% nzvimbo pa 100 μm2). Maumbirwo asina kurongeka nehukuru hwawo mudhayagiramu ndezvekufananidzira chete uye hazvienderane nenzvimbo chaidzo.
NGF inopenya yakakuriswa neCVD yakambotamisirwa kunzvimbo dzisina silicon uye inoshandiswa mumasero ezuva15,16. Kubudirira kwekushandura simba (PCE) kunoguma ne1.5%. Aya maNGF anoita mabasa akawanda akadai se active compound layers, charge transport pathways, uye transparent electrodes15,16. Zvisinei, graphite film haina kufanana. Kuwedzera kugadziriswa kunodiwa nekunyatsodzora sheet resistance uye optical transmittance yegraphite electrode, sezvo zvinhu zviviri izvi zvichiita basa rakakosha mukuona kukosha kwePCE yesolar cell15,16. Kazhinji, graphene films dzinoonekwa ne97.7%, asi dzine sheet resistance ye200–3000 ohms/sq.16. Kudzivirira kwepamusoro kwemafirimu egraphene kunogona kuderedzwa nekuwedzera huwandu hwe layers (multiple transfer of graphene layers) uye doping neHNO3 (~30 Ohm/sq.)66. Zvisinei, maitiro aya anotora nguva yakareba uye akasiyana transfer layers haagari achibata zvakanaka. NGF yedu yekumberi ine zvinhu zvakaita se 2000 S/cm, resistance yepepa refirimu 50 ohm/sq. uye 62% kujeka, zvichiita kuti ive imwe nzira inoshanda yekufambisa machaneli kana ma counter electrodes mumasero ezuva 15,16.
Kunyangwe chimiro nemakemikari epamusoro eBS-NGF zvakafanana neFS-NGF, kuomarara kwayo kwakasiyana ("Kukura kweFS- neBS-NGF"). Kare, taishandisa graphite 22 yakatetepa zvakanyanya se sensor yegesi. Saka, takaedza kugona kwekushandisa BS-NGF pamabasa ekuona gasi (Mufananidzo SI10). Kutanga, zvikamu zveBS-NGF zvakakura mm2 zvakatamisirwa kune interdigitating electrode sensor chip (Mufananidzo SI10a-c). Ruzivo rwekugadzira chip rwakambotaurwa; nzvimbo yayo inoshanda i9 mm267. Mumifananidzo yeSEM (Mufananidzo SI10b na c), electrode yegoridhe iri pasi inoonekwa zvakajeka kuburikidza neNGF. Zvakare, zvinogona kuonekwa kuti kufukidzwa kwechip yakaenzana kwakaitwa kune ese masampuli. Kuyerwa kwesensa yegesi yemagasi akasiyana-siyana kwakanyorwa (Mufananidzo SI10d) (Mufananidzo SI11) uye mwero wemhinduro unobuda unoratidzwa muMifananidzo SI10g. Zvingangodaro pamwe chete nemamwe magasi anopindira anosanganisira SO2 (200 ppm), H2 (2%), CH4 (200 ppm), CO2 (2%), H2S (200 ppm) uye NH3 (200 ppm). Chimwe chikonzero chingangove NO2. hunhu hwemagetsi hwegasi22,68. Kana yakanyikwa pamusoro pegraphene, inoderedza kunyudzwa kwemaerekitironi nehurongwa. Kuenzanisa data renguva yekupindura yeBS-NGF sensor nemasensa akamboburitswa kunoratidzwa muTable SI2. Maitiro ekugadzirisazve masensa eNGF uchishandisa UV plasma, O3 plasma kana thermal (50–150°C) kurapwa kwemasamples akafumurwa kuri kuenderera mberi, zvichiteverwa nekushandiswa kwemasystems akapinzwa69.
Munguva yeCVD, kukura kwegraphene kunoitika kumativi ese e catalyst substrate41. Zvisinei, BS-graphene inowanzo buritswa panguva yekufambisa41. Muchidzidzo ichi, tinoratidza kuti kukura kweNGF kwepamusoro-soro uye kutamiswa kweNGF isina polymer kunogona kuwanikwa kumativi ese ekutsigira catalyst. BS-NGF yakatetepa (~80 nm) kupfuura FS-NGF (~100 nm), uye musiyano uyu unotsanangurwa nekuti BS-Ni haina kuratidzwa zvakananga nekuyerera kwegasi rinotangira. Takaonawo kuti kuomarara kweNiAR substrate kunokanganisa kuomarara kweNGF. Mhedzisiro iyi inoratidza kuti FS-NGF yakakura inogona kushandiswa sechinhu chinotangira graphene (nenzira yekubvisa furuu70) kana senzira inofambisa mhepo mumasero ezuva15,16. Kusiyana neizvi, BS-NGF ichashandiswa pakuona gasi (Mufananidzo SI9) uye pamwe kune masisitimu ekuchengetedza simba71,72 uko kuomarara kwayo pamusoro kuchabatsira.
Tichifunga zviri pamusoro apa, zvinobatsira kusanganisa basa razvino nemafirimu egraphite akamboburitswa akarimwa neCVD uye kushandisa nickel foil. Sezvinogona kuonekwa muTafura 2, kumanikidzwa kwakakwirira kwatakashandisa kwakapfupisa nguva yekuita (danho rekukura) kunyangwe patembiricha yakaderera (iri pakati pe850–1300 °C). Takawanawo kukura kukuru kupfuura zvakajairika, zvichiratidza mukana wekuwedzera. Kune zvimwe zvinhu zvekufunga nezvazvo, zvimwe zvacho zvatakaisa patafura.
NGF yemhando yepamusoro ine mativi maviri yakakuriswa panickel foil neCVD inokonzeresa kupenya. Nekubvisa ma polymer substrates echinyakare (akadai seaya anoshandiswa muCVD graphene), tinowana kutamiswa kwakachena uye kusina kukanganisa kweNGF (yakakuriswa kumashure nepamberi penickel foil) kune akasiyana ma process-critical substrates. Zvinonyanya kukosha, NGF inosanganisira FLG neMLG regions (kazhinji 0.1% kusvika 3% pa 100 µm2) ayo akabatanidzwa zvakanaka mufirimu yakakora. Planar TEM inoratidza kuti matunhu aya akaumbwa nema stacks maviri kusvika matatu e graphite/graphene particles (makristaro kana layers, zvichiteerana), mamwe acho ane rotational mismatch ye 10–20°. FLG neMLG regions ndiwo anotarisira kuti FS-NGF ionekwe nechiedza chinoonekwa. Kana ari ma sheets ekumashure, anogona kutakurwa akaenzana nema sheets ekumberi uye, sezvakaratidzwa, anogona kuva nechinangwa chekushanda (semuenzaniso, chekuona gasi). Zvidzidzo izvi zvinobatsira zvikuru mukuderedza marara nemitengo muma industrial scale CVD processes.
Kazhinji, ukobvu hweCVD NGF huri pakati pemapepa egraphene (akaderera uye akawanda-layer) uye mapurasitiki egraphite eindasitiri (micrometer). Mhando dzakasiyana dzezvinhu zvavo zvinonakidza, pamwe chete nenzira iri nyore yatakagadzira yekugadzira nekutakura, zvinoita kuti mafirimu aya anyatsokodzera kushandiswa kunoda kushanda kwegraphite, pasina kushandisa simba rakawanda rinoshandiswa pakugadzira maindasitiri.
Foil ye nickel ine ukobvu hwe 25 μm (99.5% pureness, Goodfellow) yakaiswa mu CVD reactor yekutengeserana (Aixtron 4-inch BMPro). Sisitimu yacho yakacheneswa ne argon ndokuendeswa ku base pressure ye 10-3 mbar. Zvadaro nickel foil yakaiswa. mu Ar/H2 (Mushure mekudzvanya Ni foil kwemaminitsi mashanu, foil yacho yakaiswa ku pressure ye 500 mbar pa 900 °C. NGF yakaiswa mukuyerera kwe CH4/H2 (100 cm3 imwe neimwe) kwemaminitsi mashanu. Sampuro yakazotonhodzwa kusvika patembiricha iri pasi pe 700 °C uchishandisa Ar flow (4000 cm3) pa 40 °C/min. Ruzivo rwekugadzirisa maitiro ekukura kwe NGF runotsanangurwa kune dzimwe nzvimbo30.
Maumbirwo epamusoro emuenzaniso akaoneswa neSEM achishandisa maikorosikopu yeZeiss Merlin (1 kV, 50 pA). Kuoma kwemusanganiswa wesampuro uye ukobvu hweNGF zvakayerwa uchishandisa AFM (Dimension Icon SPM, Bruker). Kuyerwa kweTEM neSAED kwakaitwa uchishandisa maikorosikopu yeFEI Titan 80–300 Cubed ine pfuti inopenya zvikuru (300 kV), monochromator yeFEI Wien uye corrector yeCEOS lens spherical aberration kuti vawane mhedzisiro yekupedzisira. spatial resolution 0.09 nm. Samples dzeNGF dzakatamisirwa kumagridi emhangura akaputirwa necarbon lacy kuti dzifananidzwe neTEM uye SAED structure analysis. Saka, akawanda emasampuro flocs akasungirirwa mumaburi e supporting membrane. Samples dzeNGF dzakatamisirwa dzakaongororwa neXRD. Mapatani eX-ray diffraction akawanikwa uchishandisa poda diffractometer (Brucker, D2 phase shifter ine Cu Kα source, 1.5418 Å uye LYNXEYE detector) uchishandisa Cu radiation source ine beam spot dhayamita ye3 mm.
Kuyerwa kwakawanda kweRaman point kwakanyorwa uchishandisa maikorosikopu ye confocal integrating (Alpha 300 RA, WITeC). Laser ye532 nm ine simba shoma rekuburitsa (25%) yakashandiswa kudzivirira migumisiro inokonzerwa nekupisa. X-ray photoelectron spectroscopy (XPS) yakaitwa paKratos Axis Ultra spectrometer pamusoro penzvimbo yesample ye300 × 700 μm2 uchishandisa monochromatic Al Kα radiation (hν = 1486.6 eV) nesimba re150 W. Resolution spectra yakawanikwa pa transmission energy ye160 eV ne20 eV, zvichiteerana. NGF samples dzakatamisirwa paSiO2 dzakachekwa kuita zvidimbu (3 × 10 mm2 imwe neimwe) uchishandisa PLS6MW (1.06 μm) ytterbium fiber laser pa30 W. Copper wire contacts (50 μm gobvu) dzakagadzirwa uchishandisa silver paste pasi pe optical microscope. Kuedzwa kwemagetsi uye Hall effect kwakaitwa pamasampuli aya pa300 K uye shanduko yesimba remagineti ye± 9 Tesla musystem yekuyera hunhu hwemuviri (PPMS EverCool-II, Quantum Design, USA). Maspectra eUV-vis akatapurirwa akarekodhwa achishandisa Lambda 950 UV-vis spectrophotometer iri mu350-800 nm NGF yakaendeswa kuma quartz substrates uye quartz reference samples.
Chinoongorora chemakemikari (interdigitated electrode chip) chakasungirirwa pabhodhi redunhu rakadhindwa rakagadzirwa 73 uye chinodzivisa chakaburitswa kwenguva pfupi. Bhodhi redunhu rakadhindwa raive pariri rakabatana nemagetsi ekubatana uye rakaiswa mukati mekamuri rinonzwa gasi 74. Kuyerwa kwekudzivirira kwakatorwa pavoltage ye1 V nekutarisa kunoenderera mberi kubva pakutsvaira kusvika pakubuda mugasi uye wozochenesa zvakare. Pakutanga kamuri rakacheneswa nekuchenesa nenitrogen pa200 cm3 kweawa imwe chete kuti ive nechokwadi chekuti mamwe ma analytes ese ari mukamuri abviswa, kusanganisira hunyoro. Ma analytes ega ega akazoburitswa zvishoma nezvishoma mukamuri nechiyero chakafanana che200 cm3 nekuvhara silinda yeN2.
Shanduro yakagadziridzwa yechinyorwa chino yakabudiswa uye inogona kuwanikwa kuburikidza nelink iri pamusoro pechinyorwa.
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