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A cikin wannan aikin, an haɗa mahaɗan rGO/nZVI a karon farko ta amfani da hanya mai sauƙi kuma mai kyau ga muhalli ta amfani da ruwan ganyen Sophora mai launin rawaya a matsayin wakili mai ragewa da mai daidaita don bin ƙa'idodin sunadarai "kore", kamar haɗa sinadarai marasa lahani. An yi amfani da kayan aiki da yawa don tabbatar da nasarar haɗa mahaɗan, kamar SEM, EDX, XPS, XRD, FTIR, da zeta, wanda ke nuna nasarar ƙirƙirar mahaɗan. An kwatanta ƙarfin cire sabbin mahaɗan da tsarkakakken nZVI a yawan farawa daban-daban na doxycycline na maganin rigakafi don bincika tasirin haɗin gwiwa tsakanin rGO da nZVI. A ƙarƙashin yanayin cirewa na 25mg L-1, 25°C da 0.05g, ƙimar cirewar nZVI mai tsarki shine 90%, yayin da ƙimar cirewar doxycycline mai sha'awa ta mahaɗan rGO/nZVI ya kai 94.6%, yana tabbatar da cewa nZVI da rGO. Tsarin shaƙar iska ya yi daidai da tsari na biyu na karya kuma yana cikin jituwa da samfurin Freundlich tare da matsakaicin ƙarfin shaƙar iska na 31.61 mg g-1 a 25 °C da pH 7. An gabatar da wata hanya mai ma'ana don cire DC. Bugu da ƙari, sake amfani da haɗin rGO/nZVI ya kasance 60% bayan zagayowar sake farfadowa shida a jere.
Karancin ruwa da gurɓataccen iska yanzu babbar barazana ce ga dukkan ƙasashe. A cikin 'yan shekarun nan, gurɓataccen ruwa, musamman gurɓataccen maganin rigakafi, ya ƙaru saboda ƙaruwar samarwa da amfani da shi a lokacin annobar COVID-191,2,3. Saboda haka, haɓaka fasaha mai inganci don kawar da maganin rigakafi a cikin ruwan shara aiki ne na gaggawa.
Ɗaya daga cikin magungunan rigakafi masu jure wa ƙwayoyin cuta masu kama da juna daga ƙungiyar tetracycline shine doxycycline (DC)4,5. An ruwaito cewa ragowar DC a cikin ruwan ƙasa da ruwan saman ba za a iya haɗa su ba, kashi 20-50% ne kawai ake haɗa su, sauran kuma ana sakin su cikin muhalli, wanda ke haifar da matsaloli masu tsanani na muhalli da lafiya6.
Fuskantar DC a ƙananan matakai na iya kashe ƙwayoyin cuta masu amfani da hasken rana a cikin ruwa, suna barazana ga yaɗuwar ƙwayoyin cuta masu kashe ƙwayoyin cuta, da kuma ƙara juriya ga ƙwayoyin cuta, don haka dole ne a cire wannan gurɓataccen abu daga ruwan sharar gida. Lalacewar DC ta halitta a cikin ruwa tsari ne mai jinkiri sosai. Tsarin sinadarai kamar photolysis, biodegradation da adsorption na iya raguwa ne kawai a ƙananan yawa da kuma a ƙananan rates7,8. Duk da haka, hanya mafi araha, sauƙi, mai sauƙin sarrafawa da inganci ita ce adsorption9,10.
Nano sifili valent iron (nZVI) abu ne mai ƙarfi wanda zai iya cire maganin rigakafi da yawa daga ruwa, gami da metronidazole, diazepam, ciprofloxacin, chloramphenicol, da tetracycline. Wannan ikon ya samo asali ne saboda kyawawan halaye da nZVI ke da su, kamar yawan amsawa, babban yanki, da wurare da yawa na ɗaurewa na waje11. Duk da haka, nZVI yana da saurin taruwa a cikin ruwa saboda ƙarfin van der Wells da manyan halayen maganadisu, wanda ke rage tasirinsa wajen cire gurɓatattun abubuwa saboda samuwar yadudduka na oxide waɗanda ke hana amsawar nZVI10,12. Ana iya rage taruwar ƙwayoyin nZVI ta hanyar gyara saman su da surfactants da polymers ko ta hanyar haɗa su da wasu kayan nano a cikin nau'in mahaɗan, wanda ya tabbatar da cewa hanya ce mai kyau don inganta kwanciyar hankali a cikin muhalli13,14.
Graphene wani abu ne mai girman carbon mai girma biyu wanda ya ƙunshi ƙwayoyin carbon masu haɗaka da aka shirya a cikin ragar zuma. Yana da babban yanki na saman, ƙarfin injina mai mahimmanci, kyakkyawan aikin electrocatalytic, babban ƙarfin zafi, saurin motsi na electrons, da kuma kayan ɗaukar kaya masu dacewa don tallafawa ƙwayoyin nanoparticles marasa tsari a saman sa. Haɗin ƙwayoyin nanoparticles na ƙarfe da graphene na iya wuce fa'idodin kowane abu daban-daban, kuma saboda kyawawan halayensa na zahiri da sinadarai, yana samar da mafi kyawun rarraba ƙwayoyin nanoparticles don ingantaccen maganin ruwa15.
Cirewar tsirrai shine mafi kyawun madadin magungunan rage sinadarai masu cutarwa waɗanda ake amfani da su wajen haɗa sinadarin graphene oxide (rGO) da nZVI saboda suna samuwa, masu araha, mataki ɗaya, masu aminci ga muhalli, kuma ana iya amfani da su azaman magungunan rage sinadarai. Kamar flavonoids da mahaɗan phenolic suma suna aiki azaman mai daidaita sinadarai. Saboda haka, an yi amfani da cirewar ganyen Atriplex halimus L. azaman maganin gyarawa da rufewa don haɗawar mahaɗan rGO/nZVI a cikin wannan binciken. Atriplex halimus daga dangin Amaranthaceae itace ce mai son nitrogen mai tsayi tare da kewayon yanayi mai faɗi16.
A cewar wallafe-wallafen da ake da su, an fara amfani da Atriplex halimus (A. halimus) don yin haɗin rGO/nZVI a matsayin hanyar haɗa abubuwa masu araha da aminci ga muhalli. Don haka, manufar wannan aikin ta ƙunshi sassa huɗu: (1) phytosynthesis na rGO/nZVI da haɗin nZVI na iyaye ta amfani da cirewar ganyen ruwa na halimus, (2) halayyar haɗin phytosynthesized ta amfani da hanyoyi da yawa don tabbatar da nasarar ƙirƙirar su, (3) nazarin tasirin haɗin gwiwa na rGO da nZVI a cikin shawa da cire gurɓatattun ƙwayoyin cuta na doxycycline a ƙarƙashin sigogi daban-daban na amsawa, inganta yanayin tsarin shawa, (3) bincika kayan haɗin gwiwa a cikin magunguna daban-daban bayan zagayowar sarrafawa.
Doxycycline hydrochloride (DC, MM = 480.90, dabarar sinadarai C22H24N2O·HCl, 98%), ƙarfe chloride hexahydrate (FeCl3.6H2O, 97%), foda graphite da aka saya daga Sigma-Aldrich, Amurka. An sayi Sodium hydroxide (NaOH, 97%), ethanol (C2H5OH, 99.9%) da hydrochloric acid (HCl, 37%) daga Merck, Amurka. An sayi NaCl, KCl, CaCl2, MnCl2 da MgCl2 daga Tianjin Comio Chemical Reagent Co., Ltd. Duk abubuwan haɗin suna da tsarkin nazari sosai. An yi amfani da ruwan da aka tace sau biyu don shirya duk ruwan da ke cikinsa.
An tattara samfuran A. halimus daga mazauninsu na halitta a cikin Nilu Delta da kuma ƙasashen da ke bakin tekun Bahar Rum na Masar. An tattara kayan shuka bisa ga ƙa'idodin ƙasa da na duniya masu dacewa17. Farfesa Manal Fawzi ya gano samfuran shuka bisa ga Boulos18, kuma Ma'aikatar Kimiyyar Muhalli ta Jami'ar Alexandria ta ba da izinin tattara nau'ikan tsire-tsire da aka yi nazari a kansu don dalilai na kimiyya. Ana gudanar da samfuran takardun shaida a Herbarium na Jami'ar Tanta (TANE), takardun shaida masu lamba 14 122–14 127, wani gidan ciyawa na jama'a wanda ke ba da damar samun kayan da aka ajiye. Bugu da ƙari, don cire ƙura ko datti, a yanka ganyen shukar zuwa ƙananan guntu, a wanke sau 3 da famfo da ruwan da aka tace, sannan a bushe a 50°C. An niƙa shukar, an nutsar da 5 g na foda mai laushi a cikin 100 ml na ruwan da aka tace sannan a juya a 70°C na tsawon minti 20 don samun ruwan da aka tace. An tace ruwan da aka samo daga Bacillus nicotianae ta hanyar takardar tacewa ta Whatman kuma an adana shi a cikin bututu masu tsabta da aka tace a 4°C don ƙarin amfani.
Kamar yadda aka nuna a Hoto na 1, an yi GO daga foda graphite ta hanyar hanyar Hummers da aka gyara. An watsa 10 MG na foda GO a cikin 50 ml na ruwan da aka cire ionized na tsawon minti 30 a ƙarƙashin sonication, sannan aka haɗa 0.9 g na FeCl3 da 2.9 g na NaAc na tsawon minti 60. An ƙara 20 ml na cirewar ganyen atriplex a cikin ruwan da aka juya tare da juyawa kuma aka bar shi a 80°C na tsawon awanni 8. An tace murfin baƙar fata da ya haifar. An wanke nanocomposites da aka shirya da ethanol da ruwan bidistilled sannan aka busar da su a cikin tanda mai injin tsotsa a 50°C na tsawon awanni 12.
Hotunan tsari da na dijital na haɗakar kore na hadaddun rGO/nZVI da nZVI da kuma cire maganin rigakafi na DC daga gurɓataccen ruwa ta amfani da ruwan Atriplex halimus.
A taƙaice, kamar yadda aka nuna a Hoto na 1, an ƙara 10 ml na maganin baƙin ƙarfe chloride mai ɗauke da ions 0.05 M Fe3+ a cikin ruwan da aka zuba a cikin 20 ml na ruwan da aka cire daga ganyen mai ɗaci na tsawon mintuna 60 tare da dumamawa da juyawa matsakaici, sannan aka sanya maganin a cikin injin centrifuge a 14,000 rpm (Hermle , 15,000 rpm) na tsawon mintuna 15 don samar da ƙwayoyin baƙi, waɗanda aka wanke sau 3 da ethanol da ruwan da aka tace sannan aka busar da su a cikin tanda mai sanyi a 60°C. dare ɗaya.
An siffanta mahaɗan rGO/nZVI da nZVI masu siffar tsirrai ta hanyar amfani da na'urar hangen nesa ta UV (T70/T80 jerin UV/Vis spectrophotometers, PG Instruments Ltd, UK) a cikin kewayon ɗaukar hoto na 200-800 nm. Don yin nazarin yanayin ƙasa da rarraba girman mahaɗan rGO/nZVI da nZVI, an yi amfani da na'urar hangen nesa ta TEM (JOEL, JEM-2100F, Japan, ƙarfin lantarki mai sauri 200 kV). Don kimanta ƙungiyoyin aiki waɗanda za su iya shiga cikin cirewar tsire-tsire waɗanda ke da alhakin dawo da tsarin daidaitawa, an gudanar da na'urar hangen nesa ta FT-IR (na'urar hangen nesa ta JASCO a cikin kewayon 4000-600 cm-1). Bugu da ƙari, an yi amfani da na'urar nazarin zeta (Zetasizer Nano ZS Malvern) don nazarin cajin saman nanomaterials da aka haɗa. Don auna bambancin hasken X-ray na kayan nano na foda, an yi amfani da na'urar auna hasken X-ray diffractometer (X'PERT PRO, Netherlands), tana aiki a yanayin zafi (40 mA), ƙarfin lantarki (45 kV) a cikin kewayon 2θ daga 20° zuwa 80° da kuma hasken CuKa1 (\(\lambda =\ ) 1.54056 Ao). Na'urar auna hasken X-ray mai watsa makamashi (EDX) (samfurin JEOL JSM-IT100) ita ce ke da alhakin nazarin abubuwan da ke cikin sinadaran lokacin tattara hasken X-ray na Al K-α monochromatic daga -10 zuwa 1350 eV akan XPS, girman tabo 400 μm K-ALPHA (Thermo Fisher Scientific, Amurka) makamashin watsa cikakken bakan shine 200 eV kuma kunkuntar bakan shine 50 eV. Ana matse samfurin foda a kan mai riƙe samfurin, wanda aka sanya a cikin ɗakin injin. An yi amfani da bakan C 1 a matsayin nuni a 284.58 eV don tantance ƙarfin ɗaurewa.
An gudanar da gwaje-gwajen adsorption don gwada ingancin nanocomposites na rGO/nZVI da aka haɗa wajen cire doxycycline (DC) daga ruwan da aka tace. An gudanar da gwaje-gwajen adsorption a cikin flasks na Erlenmeyer na 25 ml a saurin girgiza na 200 rpm akan na'urar girgiza orbital (Stuart, Orbital Shaker/SSL1) a 298 K. Ta hanyar narkar da maganin DC stock (1000 ppm) da ruwan bidistilled. Don tantance tasirin maganin rGO/nSVI akan ingancin adsorption, an ƙara nanocomposites masu nauyi daban-daban (0.01–0.07 g) zuwa 20 ml na maganin DC. Don nazarin kinetics da adsorption isotherms, an nutsar da 0.05 g na adsorbent a cikin ruwan CD tare da yawan farko (25–100 mg L–1). An yi nazarin tasirin pH akan cire DC a pH (3-11) da kuma yawan farko na 50 mg L-1 a 25°C. Daidaita pH na tsarin ta hanyar ƙara ƙaramin adadin HCl ko NaOH (mita Crison pH, mita pH, pH 25). Bugu da ƙari, an binciki tasirin zafin amsawa akan gwaje-gwajen shaye-shaye a cikin kewayon 25-55°C. An yi nazarin tasirin ƙarfin ionic akan tsarin shaye-shaye ta hanyar ƙara yawan NaCl (0.01-4 mol L-1) daban-daban a farkon yawan DC na 50 mg L-1, pH 3 da 7), 25°C, da kuma adadin shaye-shaye na 0.05 g. An auna shaƙar DC mara shaƙar ta amfani da na'urar auna haske ta UV-Vis mai walƙiya mai walƙiya biyu (jerin T70/T80, PG Instruments Ltd, UK) wacce aka sanye da ma'aunin ma'aunin quartz mai tsawon santimita 1.0 a matsakaicin tsayin tsayi (λmax) na 270 da 350 nm. An auna kaso na cire maganin rigakafi na DC (R%; Eq. 1) da adadin shaƙar DC, qt, Eq. 2 (mg/g) ta amfani da lissafin da ke ƙasa.
inda %R shine ƙarfin cire DC (%), Co shine farkon yawan DC a lokacin 0, kuma C shine yawan DC a lokacin t, bi da bi (mg L-1).
inda qe shine adadin DC da aka sha a kowace naúrar nauyin mai sha (mg g-1), Co da Ce sune yawan da ake samu a lokacin sifili da kuma a daidaito, bi da bi (mg l-1), V shine girman maganin (l), kuma m shine reagent na taro na sha (g).
Hotunan SEM (Hotuna 2A–C) suna nuna yanayin lamellar na mahaɗin rGO/nZVI tare da ƙwayoyin ƙarfe masu siffar ƙwallo waɗanda aka watsar a samansa, wanda ke nuna nasarar haɗewar nZVI NPs zuwa saman rGO. Bugu da ƙari, akwai wasu wrinkles a cikin ganyen rGO, suna tabbatar da cire ƙungiyoyin da ke ɗauke da iskar oxygen a lokaci guda tare da dawo da A. halimus GO. Waɗannan manyan wrinkles suna aiki azaman wuraren ɗaukar NPs na ƙarfe masu aiki. Hotunan nZVI (Hoto na 2D-F) sun nuna cewa NPs na ƙarfe masu siffar ƙwallo sun warwatse sosai kuma ba su taruwa ba, wanda ya faru ne saboda yanayin rufewar abubuwan da ke cikin shukar. Girman ƙwayoyin ya bambanta tsakanin 15-26 nm. Duk da haka, wasu yankuna suna da yanayin mesoporous tare da tsarin bulges da cavities, wanda zai iya samar da ƙarfin sha na nZVI mai inganci, tunda suna iya ƙara yiwuwar kama ƙwayoyin DC a saman nZVI. Lokacin da aka yi amfani da ruwan Rosa Damascus don haɗa nZVI, NPs da aka samu ba su da kama da juna, tare da voids da siffofi daban-daban, wanda ya rage ingancinsu a cikin shaƙar Cr(VI) kuma ya ƙara lokacin amsawa 23. Sakamakon ya yi daidai da nZVI da aka haɗa daga ganyen itacen oak da mulberry, waɗanda galibi ƙananan ƙwayoyin halitta ne masu siffar ƙwallo tare da girman nanometer daban-daban ba tare da haɗuwa a bayyane ba.
Hotunan SEM na haɗakar rGO/nZVI (AC), nZVI (D, E) da kuma tsarin EDX na haɗakar nZVI/rGO (G) da nZVI (H).
An yi nazarin abubuwan da suka shafi sinadaran rGO/nZVI da nZVI da aka haɗa da tsire-tsire ta amfani da EDX (Hoto na 2G, H). Bincike ya nuna cewa nZVI ya ƙunshi carbon (38.29% ta taro), oxygen (47.41% ta taro) da baƙin ƙarfe (11.84% ta taro), amma akwai wasu abubuwa kamar phosphorus24, waɗanda za a iya samu daga abubuwan da aka cire daga tsire-tsire. Bugu da ƙari, babban kaso na carbon da oxygen ya faru ne saboda kasancewar sinadarai masu rai daga abubuwan da aka cire daga tsire-tsire a cikin samfuran nZVI na ƙarƙashin ƙasa. Waɗannan abubuwan suna rarraba daidai gwargwado akan rGO amma a cikin rabo daban-daban: C (39.16 wt %), O (46.98 wt %) da Fe (10.99 wt %), EDX rGO/nZVI kuma yana nuna kasancewar wasu abubuwa kamar S, waɗanda za a iya dangantawa da abubuwan da aka cire daga tsire-tsire, ana amfani da su. Rabon C:O da sinadarin ƙarfe a cikin haɗin rGO/nZVI ta amfani da A. halimus ya fi kyau fiye da amfani da ruwan ganyen eucalyptus, domin yana siffanta abun da ke cikin C (23.44 wt.%), O (68.29 wt.%) da Fe (8.27 wt.%). wt %) 25. Nataša et al., 2022 sun ba da rahoton irin wannan abun da ke cikin nZVI da aka haɗa daga ganyen itacen oak da mulberry kuma sun tabbatar da cewa ƙungiyoyin polyphenol da sauran ƙwayoyin da ke cikin ruwan ganyen suna da alhakin rage aikin.
Siffar nZVI da aka haɗa a cikin tsire-tsire (Hoto na S2A,B) ta kasance mai siffar ƙwallo kuma ba ta daidaita ba, tare da matsakaicin girman barbashi na 23.09 ± 3.54 nm, duk da haka an lura da tarin sarƙoƙi saboda ƙarfin van der Waals da ferromagnetism. Wannan siffar barbashi mafi yawanci tana da girma da siffar ƙwallo mai siffar ƙwallo ya yi daidai da sakamakon SEM. An gano irin wannan lura ta Abdelfatah et al. a cikin 2021 lokacin da aka yi amfani da cirewar ganyen castor wajen haɗa nZVI11. Ruelas tuberosa cirewar ganye NPs da aka yi amfani da su azaman wakili mai ragewa a cikin nZVI suma suna da siffar ƙwallo mai diamita na 20 zuwa 40 nm26.
Hotunan TEM masu haɗakar rGO/nZVI (Hoto na S2C-D) sun nuna cewa rGO wani babban tsari ne mai lanƙwasa da lanƙwasa wanda ke samar da wurare da yawa na ɗaukar nauyin nZVI NPs; wannan yanayin lamellar kuma yana tabbatar da nasarar ƙirƙirar rGO. Bugu da ƙari, nZVI NPs suna da siffar zagaye tare da girman barbashi daga 5.32 zuwa 27 nm kuma an saka su a cikin layin rGO tare da watsawa kusan iri ɗaya. An yi amfani da cirewar ganyen Eucalyptus don haɗa Fe NPs/rGO; Sakamakon TEM kuma ya tabbatar da cewa wrinkles a cikin layin rGO sun inganta watsawar Fe NPs fiye da tsarkakakken Fe NPs kuma sun ƙara amsawar mahaɗan. Bagheri et al. 28 sun sami irin wannan sakamakon lokacin da aka ƙera mahaɗan ta amfani da dabarun ultrasonic tare da matsakaicin girman ƙarfe nanoparticle kusan 17.70 nm.
An nuna FTIR spectra na A. halimus, nZVI, GO, rGO, da rGO/nZVI a cikin Fig. 3A. Kasancewar ƙungiyoyin aiki a saman ganyen A. halimus ya bayyana a 3336 cm-1, wanda ya yi daidai da polyphenols, da 1244 cm-1, wanda ya yi daidai da ƙungiyoyin carbonyl da furotin ya samar. An kuma lura da wasu ƙungiyoyi kamar alkanes a 2918 cm-1, alkenes a 1647 cm-1 da kuma CO-O-CO a 1030 cm-1, wanda ke nuna kasancewar abubuwan da ke cikin shuka waɗanda ke aiki a matsayin masu rufewa kuma suna da alhakin murmurewa daga Fe2+ zuwa Fe0 da GO zuwa rGO29. Gabaɗaya, spectra na nZVI yana nuna kololuwar sha kamar sukari mai ɗaci, amma tare da ɗan canjin matsayi. Wani babban madauri yana bayyana a 3244 cm-1 wanda ke da alaƙa da girgizar OH (phenols), kololuwar da ke 1615 ta yi daidai da C=C, kuma madauri a 1546 da 1011 cm-1 suna tasowa saboda shimfiɗa C=O (polyphenols da flavonoids), an kuma lura da ƙungiyoyin CN na amines masu aromatic da amines masu aliphatic a 1310 cm-1 da 1190 cm-1, bi da bi13. FTIR bakan GO yana nuna kasancewar ƙungiyoyi da yawa masu ɗauke da iskar oxygen mai ƙarfi, gami da madauri mai shimfiɗa alkoxy (CO) a 1041 cm-1, madauri mai shimfiɗa epoxy (CO) a 1291 cm-1, madauri mai shimfiɗa C=O. wani rukunin girgizar C=C mai tsayi a 1619 cm-1, wani rukunin a 1708 cm-1 da kuma babban rukunin girgizar OH mai tsayi a 3384 cm-1 sun bayyana, wanda aka tabbatar ta hanyar ingantaccen hanyar Hummers, wanda ya yi nasarar lalata tsarin graphite. Lokacin da ake kwatanta haɗin rGO da rGO/nZVI tare da GO spectra, ƙarfin wasu ƙungiyoyi masu ɗauke da oxygen, kamar OH a 3270 cm-1, ya ragu sosai, yayin da wasu, kamar C=O a 1729 cm-1, sun ragu gaba ɗaya. wanda ke nuna nasarar cire ƙungiyoyin aiki masu ɗauke da oxygen a cikin GO ta hanyar cire A. halimus. An lura da sabbin kololuwar halayen rGO a C=C a kusan 1560 da 1405 cm-1, wanda ke tabbatar da raguwar GO zuwa rGO. An lura da bambance-bambance daga 1043 zuwa 1015 cm-1 da kuma daga 982 zuwa 918 cm-1, wataƙila saboda haɗa kayan shuka31,32. Weng et al., 2018 sun kuma lura da raguwar ƙungiyoyin aiki masu amfani da iskar oxygen a cikin GO, wanda ya tabbatar da nasarar samuwar rGO ta hanyar bioreduction, tunda cirewar ganyen eucalyptus, waɗanda aka yi amfani da su don haɗa ƙananan haɗin ƙarfe na graphene oxide, sun nuna kusancin FTIR na ƙungiyoyin aiki na ɓangaren shuka. 33.
A. FTIR bakan gallium, nZVI, rGO, GO, composed rGO/nZVI (A). Haɗaɗɗun Roentgenogrammy rGO, GO, nZVI da rGO/nZVI (B).
An tabbatar da samuwar rGO/nZVI da nZVI ta hanyar tsarin diffraction na X-ray (Hoto na 3B). An lura da babban kololuwar Fe0 a 2Ɵ 44.5°, wanda ya yi daidai da ma'aunin (110) (JCPDS lamba 06–0696)11. Wani kololuwar a 35.1° na jirgin (311) an danganta shi da magnetite Fe3O4, 63.2° na iya dangantawa da ma'aunin Miller na jirgin (440) saboda kasancewar ϒ-FeOOH (JCPDS lamba 17-0536)34. Tsarin X-ray na GO yana nuna kololuwar kaifi a 2Ɵ 10.3° da wani kololuwar a 21.1°, yana nuna cikakken cire graphite ɗin da kuma nuna kasancewar ƙungiyoyi masu ɗauke da iskar oxygen a saman GO35. Tsarin haɗin gwiwa na rGO da rGO/nZVI sun rubuta ɓacewar kololuwar GO masu kama da juna da kuma samuwar kololuwar rGO masu faɗi a 2Ɵ 22.17 da 24.7° ga mahaɗan rGO da rGO/nZVI, bi da bi, wanda ya tabbatar da nasarar dawo da GO ta hanyar cirewar tsire-tsire. Duk da haka, a cikin tsarin haɗin gwiwa na rGO/nZVI, an lura da ƙarin kololuwar da ke da alaƙa da layin lattice na Fe0 (110) da bcc Fe0 (200) a 44.9\(^\circ\) da 65.22\(^\circ\), bi da bi.
Ƙarfin zeta shine yuwuwar da ke tsakanin layin ionic da aka haɗe a saman barbashi da kuma ruwan da ke tantance halayen electrostatic na wani abu kuma yana auna daidaitonsa37. Binciken yuwuwar Zeta na haɗakar nZVI, GO, da rGO/nZVI da aka haɗa da tsire-tsire ya nuna daidaitonsu saboda kasancewar cajin mara kyau na -20.8, -22, da -27.4 mV, bi da bi, a saman su, kamar yadda aka nuna a Hoto na S1A-C. . Irin waɗannan sakamakon sun yi daidai da rahotanni da dama waɗanda suka ambaci cewa mafita waɗanda ke ɗauke da barbashi tare da ƙimar yuwuwar zeta ƙasa da -25 mV gabaɗaya suna nuna babban matakin kwanciyar hankali saboda tura wutar lantarki tsakanin waɗannan barbashi. Haɗin rGO da nZVI yana ba da damar haɗakar ta sami ƙarin cajin mara kyau kuma don haka yana da kwanciyar hankali mafi girma fiye da ko dai GO ko nZVI kaɗai. Saboda haka, abin da ke faruwa na tura wutar lantarki zai haifar da samuwar haɗakar rGO/nZVI39 mai karko. Fuskar GO mara kyau tana ba da damar warwatsewa daidai a cikin ruwa ba tare da haɗuwa ba, wanda ke haifar da yanayi mai kyau don hulɗa da nZVI. Cajin mara kyau na iya alaƙa da kasancewar ƙungiyoyi daban-daban na aiki a cikin ruwan kankana mai ɗaci, wanda kuma yana tabbatar da hulɗar da ke tsakanin GO da abubuwan da suka fara aiki da ƙarfe da kuma ruwan shuka don samar da rGO da nZVI, bi da bi, da kuma hadaddun rGO/nZVI. Waɗannan mahaɗan tsire-tsire kuma suna iya aiki azaman abubuwan rufewa, saboda suna hana tarin ƙwayoyin nano da suka haifar kuma don haka suna ƙara kwanciyar hankali40.
An ƙayyade yanayin abubuwan da ke cikin nZVI da rGO/nZVI ta hanyar XPS (Hoto na 4). Binciken XPS gabaɗaya ya nuna cewa haɗin rGO/nZVI ya ƙunshi abubuwan C, O, da Fe, daidai da taswirar EDS (Hoto na 4F–H). Bakan C1s ya ƙunshi kololuwa uku a 284.59 eV, 286.21 eV da 288.21 eV waɗanda ke wakiltar CC, CO da C=O, bi da bi. An raba bakan O1s zuwa kololuwa uku, gami da 531.17 eV, 532.97 eV, da 535.45 eV, waɗanda aka sanya wa ƙungiyoyin O=CO, CO, da NO, bi da bi. Duk da haka, kololuwa a 710.43, 714.57 da 724.79 eV suna nufin Fe 2p3/2, Fe+3 da Fe p1/2, bi da bi. Siffar XPS ta nZVI (Hoto na 4C-E) ta nuna kololuwar abubuwan da ke cikin C, O, da Fe. Kololuwar a 284.77, 286.25, da 287.62 eV ta tabbatar da kasancewar ƙarfe-carbon gami, kamar yadda suke nuni zuwa ga CC, C-OH, da CO, bi da bi. Siffar O1s ta yi daidai da kololuwar C–O/iron carbonate guda uku (531.19 eV), hydroxyl radical (532.4 eV) da O–C=O (533.47 eV). An danganta kololuwar a 719.6 da Fe0, yayin da FeOOH ya nuna kololuwar a 717.3 da 723.7 eV, ban da haka, kololuwar a 725.8 eV yana nuna kasancewar Fe2O342.43.
Nazarin XPS na mahaɗan nZVI da rGO/nZVI, bi da bi (A, B). Cikakken bakan nZVI C1s (C), Fe2p (D), da O1s (E) da rGO/nZVI C1s (F), Fe2p (G), O1s (H).
Ma'aunin shaƙa/shaƙatawa na N2 (Hoto na 5A, B) ya nuna cewa mahaɗan nZVI da rGO/nZVI suna cikin nau'in II. Bugu da ƙari, takamaiman yankin saman (SBET) na nZVI ya ƙaru daga 47.4549 zuwa 152.52 m2/g bayan makanta da rGO. Ana iya bayanin wannan sakamakon ta hanyar raguwar halayen maganadisu na nZVI bayan makanta rGO, ta haka rage tarin ƙwayoyin cuta da ƙara yankin saman mahaɗan. Bugu da ƙari, kamar yadda aka nuna a Hoto na 5C, girman ramin (8.94 nm) na mahaɗan rGO/nZVI ya fi na ainihin nZVI (2.873 nm). Wannan sakamakon ya yi daidai da El-Monaem et al. 45.
Domin kimanta ƙarfin shaƙar iska don cire DC tsakanin mahaɗan rGO/nZVI da nZVI na asali dangane da ƙaruwar yawan ruwan da aka samu a farkon, an yi kwatancen ta hanyar ƙara yawan ruwan da aka ci gaba da sha na kowane mai shaƙar iska (0.05 g) zuwa DC a yawan ruwan da aka samu a farkon. An binciki maganin [25]. –100 mg l–1] a 25°C. Sakamakon ya nuna cewa ingancin cirewa (94.6%) na mahaɗan rGO/nZVI ya fi na nZVI na asali (90%) a ƙaramin yawan ruwa (25 mg L-1). Duk da haka, lokacin da aka ƙara yawan ruwan da aka fara sha zuwa 100 mg L-1, ingancin cirewa na rGO/nZVI da nZVI na iyaye ya ragu zuwa 70% da 65%, bi da bi (Hoto na 6A), wanda ƙila ya faru ne saboda ƙarancin wuraren aiki da lalacewar ƙwayoyin nZVI. Akasin haka, rGO/nZVI ya nuna ingantaccen cirewar DC, wanda zai iya kasancewa saboda tasirin haɗin gwiwa tsakanin rGO da nZVI, inda wuraren aiki masu ƙarfi da ake da su don shaye-shaye sun fi yawa, kuma a yanayin rGO/nZVI, za a iya shaye DC fiye da nZVI mara lahani. Bugu da ƙari, a cikin hoto na 6B ya nuna cewa ƙarfin shaye-shaye na mahaɗan rGO/nZVI da nZVI ya ƙaru daga 9.4 mg/g zuwa 30 mg/g da 9 mg/g, bi da bi, tare da ƙaruwa a cikin yawan farko daga 25-100 mg/L. -1.1 zuwa 28.73 mg g-1. Saboda haka, ƙimar cirewar DC ta kasance mara kyau tare da yawan DC na farko, wanda ya faru ne saboda ƙarancin adadin cibiyoyin amsawa da kowane mai shaye-shaye ke tallafawa don shaye-shaye da cire DC a cikin maganin. Saboda haka, daga waɗannan sakamakon za a iya kammalawa cewa haɗakar rGO/nZVI suna da ingantaccen aiki na shaye-shaye da raguwa, kuma rGO a cikin abun da ke cikin rGO/nZVI za a iya amfani da shi duka a matsayin mai shaye-shaye da kuma a matsayin kayan ɗaukar kaya.
Ingancin cirewa da ƙarfin shaƙar DC na mahaɗin rGO/nZVI da nZVI sune (A, B) [Co = 25 mg l-1–100 mg l-1, T = 25 °C, kashi = 0.05 g], pH. akan ƙarfin shaƙar da ingancin cire DC akan mahaɗin rGO/nZVI (C) [Co = 50 mg L–1, pH = 3–11, T = 25°C, kashi = 0.05 g].
Maganin pH muhimmin abu ne a nazarin hanyoyin sha, tunda yana shafar matakin ionization, speciation, da ionization na mai sha. An gudanar da gwajin a 25°C tare da yawan shan ruwa akai-akai (0.05 g) da kuma yawan farko na 50 MG L-1 a cikin kewayon pH (3-11). A cewar wani bita na wallafe-wallafe46, DC kwayar amphiphilic ce mai ƙungiyoyin aiki da yawa masu iya aiki (phenols, amino groups, alcohols) a matakan pH daban-daban. Sakamakon haka, ayyuka daban-daban na DC da tsarin da ke da alaƙa a saman mahaɗin rGO/nZVI na iya yin mu'amala ta hanyar lantarki kuma suna iya wanzuwa azaman cations, zwitterions, da anions, ƙwayar DC tana wanzuwa azaman cationic (DCH3+) a pH < 3.3, zwitterionic (DCH20) 3.3 < pH < 7.7 da anionic (DCH− ko DC2−) a PH 7.7. Sakamakon haka, ayyuka daban-daban na DC da tsarin da ke da alaƙa a saman mahaɗin rGO/nZVI na iya yin mu'amala ta hanyar lantarki kuma suna iya wanzuwa azaman cations, zwitterions, da anions, ƙwayar DC tana wanzuwa azaman cationic (DCH3+) a pH < 3.3, zwitterionic (DCH20) 3.3 < pH < 7.7 da anionic (DCH- ko DC2-) a PH 7.7. В результате различные функции ДК и связанных эlektrostatychesky da kuma mu'ujiza существать в виде катов, цвиter-ionov da kuma antyonov, molekula ДК сучеть. (DCH3+) pH <3,3, цвитер-ионный (DCH20) 3,3
An gudanar da tasirin zafin jiki akan shaƙar ruwan maganin DC a (25–55°C). Hoto na 7A ya nuna tasirin ƙaruwar zafin jiki akan ingancin cirewar maganin rigakafi na DC akan rGO/nZVI, a bayyane yake cewa ƙarfin cirewa da ƙarfin sha ya ƙaru daga 83.44% da 13.9 mg/g zuwa 47% da 7.83 mg/g., bi da bi. Wannan raguwa mai mahimmanci na iya faruwa ne saboda ƙaruwar kuzarin zafi na ions na DC, wanda ke haifar da raguwar narkewa47.
Tasirin Zafin Jiki akan Ingancin Cirewa da Ƙarfin Shafawa na CD akan rGO/nZVI Composites (A) [Co = 50 mg L–1, pH = 7, Dosage = 0.05 g], Dosage Mai Shafawa akan Cirewa Ingancin Cirewa da Cirewa Ingancin CD Tasirin Tarin Farko akan ƙarfin shawa da ingancin cirewar DC akan mahaɗin rGO/nSVI (B) [Co = 50 mg L–1, pH = 7, T = 25°C] (C, D) [Co = 25–100 mg L–1, pH = 7, T = 25 °C, dosage = 0.05 g].
An nuna tasirin ƙara yawan sinadarin rGO/nZVI mai haɗakar sinadarai daga 0.01 g zuwa 0.07 g akan ingancin cirewa da ƙarfin shaye-shaye a cikin Hoto na 7B. Ƙara yawan sinadarin ya haifar da raguwar ƙarfin shaye-shaye daga 33.43 mg/g zuwa 6.74 mg/g. Duk da haka, tare da ƙaruwar yawan sinadarin daga 0.01 g zuwa 0.07 g, ingancin cirewa yana ƙaruwa daga 66.8% zuwa 96%, wanda, saboda haka, yana iya alaƙa da ƙaruwar adadin cibiyoyin aiki akan saman nanocomposite.
An yi nazarin tasirin farko na yawan shan ruwa da kuma ingancin cirewa [25–100 mg L-1, 25°C, pH 7, kashi 0.05 g]. Lokacin da aka ƙara yawan shan ruwa daga 25 mg L-1 zuwa 100 mg L-1, kashi na cirewa na rGO/nZVI ya ragu daga 94.6% zuwa 65% (Hoto na 7C), wataƙila saboda rashin wuraren aiki da ake so. . Yana ɗaukar manyan abubuwan da ke cikin DC49. A gefe guda kuma, yayin da yawan shan ruwa ya ƙaru, ƙarfin sha shi ma ya ƙaru daga 9.4 mg/g zuwa 30 mg/g har sai an cimma daidaito (Hoto na 7D). Wannan amsawar da ba makawa ta faru ne saboda ƙaruwar ƙarfin tuƙi tare da ƙarfin DC na farko wanda ya fi ƙarfin jure wa canja wurin taro na DC ion don isa saman 50 na rGO/nZVI compound.
Lokacin hulɗa da nazarin motsi suna nufin fahimtar lokacin daidaitawar sha. Da farko, adadin DC da aka sha a cikin mintuna 40 na farko na lokacin hulɗa ya kai kusan rabin jimlar adadin da aka sha a tsawon lokacin (minti 100). Yayin da ƙwayoyin DC da ke cikin maganin suka haɗu wanda ke sa su yi ƙaura da sauri zuwa saman mahaɗin rGO/nZVI wanda ke haifar da sha mai yawa. Bayan mintuna 40, shawarwar DC ta ƙaru a hankali da sannu a hankali har sai an kai daidaito bayan mintuna 60 (Hoto na 7D). Tunda an sha mai ma'ana a cikin mintuna 40 na farko, za a sami ƙarancin karo da ƙwayoyin DC kuma za a sami ƙananan wuraren aiki ga ƙwayoyin da ba su sha ba. Saboda haka, ana iya rage ƙimar shawarwar51.
Domin fahimtar kinetics na adsorption sosai, an yi amfani da zane-zanen layi na tsari na farko na pseudo (Hoto na 8A), tsari na biyu na pseudo (Hoto na 8B), da Elovich (Hoto na 8C). Daga sigogin da aka samu daga nazarin kinetic (Tebur S1), ya bayyana cewa samfurin pseudosecond shine mafi kyawun samfurin don bayyana kinetics na adsorption, inda aka saita ƙimar R2 sama da sauran samfura biyu. Akwai kuma kamanceceniya tsakanin ƙarfin adsorption da aka ƙididdige (qe, cal). Tsarin pseudo-second da ƙimar gwaji (qe, exp.) ƙarin shaida ne cewa tsari na pseudo-second shine mafi kyawun samfurin fiye da sauran samfura. Kamar yadda aka nuna a Jadawali na 1, ƙimar α (ƙimar adsorption ta farko) da β (matsayin desorption) sun tabbatar da cewa ƙimar adsorption ta fi ƙimar desorption girma, yana nuna cewa DC yana son adsorption yadda ya kamata akan haɗin rGO/nZVI52. .
Tsarin motsin shaye-shaye na layi na tsari na biyu na karya (A), tsari na farko na karya (B) da Elovich (C) [Co = 25–100 mg l–1, pH = 7, T = 25 °C, kashi = 0.05 g].
Nazarin isotherms na adsorption yana taimakawa wajen tantance ƙarfin adsorption na adsorbent (RGO/nRVI composite) a yawan adsorbate daban-daban (DC) da yanayin zafin tsarin. An ƙididdige matsakaicin ƙarfin adsorption ta amfani da isotherm na Langmuir, wanda ya nuna cewa adsorption ɗin yayi kama da juna kuma ya haɗa da ƙirƙirar monolayer adsorbate a saman adsorbent ɗin ba tare da hulɗa tsakanin su ba53. Wasu samfuran isotherm guda biyu da ake amfani da su sosai sune samfuran Freundlich da Temkin. Kodayake ba a amfani da samfurin Freundlich don ƙididdige ƙarfin adsorption ba, yana taimakawa wajen fahimtar tsarin adsorption iri-iri kuma cewa guraben da ke kan adsorbent suna da kuzari daban-daban, yayin da samfurin Temkin yana taimakawa wajen fahimtar halayen zahiri da na sinadarai na adsorption54.
Hotuna 9A-C sun nuna layukan layin samfurin Langmuir, Freindlich, da Temkin, bi da bi. Ƙimar R2 da aka ƙididdige daga layukan Freundlich (Hoto na 9A) da Langmuir (Hoto na 9B) kuma aka gabatar a cikin Jadawali na 2 sun nuna cewa shaƙar DC akan haɗin rGO/nZVI yana bin samfuran isotherm na Freundlich (0.996) da Langmuir (0.988) da Temkin (0.985). Matsakaicin ƙarfin shaƙar (qmax), wanda aka ƙididdige ta amfani da samfurin isotherm na Langmuir, shine 31.61 mg g-1. Bugu da ƙari, ƙimar da aka ƙididdige ta hanyar rabo mara girma (RL) tana tsakanin 0 da 1 (0.097), yana nuna kyakkyawan tsarin shaƙar. In ba haka ba, madaidaicin Freundlich da aka ƙididdige (n = 2.756) yana nuna fifiko ga wannan tsarin shaƙar. A cewar samfurin layi na isotherm na Temkin (Hoto na 9C), shaƙar DC akan mahaɗin rGO/nZVI tsari ne na shaƙar jiki, tunda b shine ˂ 82 kJ mol-1 (0.408)55. Kodayake shaƙar jiki yawanci yana faruwa ne ta hanyar ƙarfin van der Waals mai rauni, shaƙar kai tsaye akan mahaɗin rGO/nZVI yana buƙatar ƙarancin kuzarin shaƙar [56, 57].
Freundlich (A), Langmuir (B), da Temkin (C) isotherms na shaƙatawa masu layi [Co = 25–100 mg L–1, pH = 7, T = 25 °C, kashi = 0.05 g]. Tsarin lissafin van't Hoff don shaƙatawa na DC ta hanyar haɗakar rGO/nZVI (D) [Co = 25–100 mg l-1, pH = 7, T = 25–55 °C da kashi = 0.05 g].
Domin kimanta tasirin canjin zafin amsawa akan cire DC daga mahaɗan rGO/nZVI, an ƙididdige sigogin thermodynamic kamar canjin entropy (ΔS), canjin enthalpy (ΔH), da canjin makamashi kyauta (ΔG) daga lissafi. 3 da 458.
inda \({K}_{e}\)=\(\frac{{C}_{Ae}}{{C}_{e}}\) – daidaitaccen daidaiton thermodynamic, Ce da CAe – rGO a cikin maganin, bi da bi /nZVI DC yawansu a ma'aunin saman. R da RT sune yanayin iskar gas da kuma zafin sha, bi da bi. Tsarin zane ln Ke akan 1/T yana ba da layi madaidaiciya (Hoto na 9D) wanda daga ciki za a iya tantance ∆S da ∆H.
Ƙimar ΔH mara kyau tana nuna cewa tsarin yana cikin yanayin zafi. A gefe guda kuma, ƙimar ΔH tana cikin tsarin sharar jiki. Ƙimar ΔG mara kyau a cikin Jadawali na 3 yana nuna cewa sharar yana yiwuwa kuma ba zato ba tsammani. Ƙimar ΔS mara kyau tana nuna babban tsari na ƙwayoyin shararwa a mahaɗin ruwa (Jadawali na 3).
Tebur na 4 ya kwatanta haɗin rGO/nZVI da sauran masu shaye-shaye da aka ruwaito a cikin binciken da ya gabata. A bayyane yake cewa haɗin VGO/nCVI yana da ƙarfin shaye-shaye mai yawa kuma yana iya zama abu mai kyau don cire maganin rigakafi na DC daga ruwa. Bugu da ƙari, shaye-shayen haɗin rGO/nZVI tsari ne mai sauri tare da lokacin daidaitawa na minti 60. Ana iya bayanin kyawawan halayen shaye-shaye na haɗin rGO/nZVI ta hanyar tasirin haɗin gwiwa na rGO da nZVI.
Sifofi 10A, B sun nuna hanyar da ta dace don cire maganin rigakafi na DC ta hanyar haɗakar rGO/nZVI da nZVI. Dangane da sakamakon gwaje-gwaje kan tasirin pH akan ingancin shaƙar DC, tare da ƙaruwa a pH daga 3 zuwa 7, shaƙar DC akan mahaɗin rGO/nZVI ba a sarrafa shi ta hanyar hulɗar electrostatic ba, tunda yana aiki azaman zwitterion; saboda haka, canji a cikin ƙimar pH bai shafi tsarin shaƙar ba. Daga baya, ana iya sarrafa hanyar shaƙar ta hanyar hulɗar da ba ta electrostatic ba kamar haɗin hydrogen, tasirin hydrophobic, da hulɗar stacking π-π tsakanin mahaɗin rGO/nZVI da DC66. An san cewa an bayyana hanyar shaƙar aromatic a saman graphene mai layi ta hanyar hulɗar stacking π–π a matsayin babban ƙarfin tuƙi. Haɗaɗɗen abu ne mai layi kamar graphene tare da matsakaicin shaƙar a 233 nm saboda canjin π-π*. Dangane da kasancewar zobba huɗu masu ƙamshi a cikin tsarin ƙwayoyin halittar DC adsorbate, mun yi hasashen cewa akwai hanyar hulɗar π-π-stacking tsakanin aromatic DC (π-electron acceptor) da yankin da ke da wadataccen π-electrons akan saman RGO. /nZVI composites. Bugu da ƙari, kamar yadda aka nuna a cikin hoto na 10B, an gudanar da nazarin FTIR don nazarin hulɗar ƙwayoyin halittar rGO/nZVI tare da DC, kuma an nuna FTIR spectra na rGO/nZVI composites bayan DC adsorption a cikin Hoto na 10B. 10b. An lura da sabon kololuwa a 2111 cm-1, wanda ya yi daidai da rawar jiki na tsarin haɗin C=C, wanda ke nuna kasancewar ƙungiyoyin aiki na halitta masu dacewa akan saman 67 rGO/nZVI. Sauran kololuwa suna canzawa daga 1561 zuwa 1548 cm-1 kuma daga 1399 zuwa 1360 cm-1, wanda kuma ya tabbatar da cewa hulɗar π-π tana taka muhimmiyar rawa wajen shaƙar graphene da gurɓatattun abubuwa na halitta68,69. Bayan shaƙar DC, ƙarfin wasu ƙungiyoyi masu ɗauke da iskar oxygen, kamar OH, ya ragu zuwa 3270 cm-1, wanda ke nuna cewa haɗin hydrogen yana ɗaya daga cikin hanyoyin shaƙar. Don haka, bisa ga sakamakon, shaƙar DC akan mahaɗin rGO/nZVI yana faruwa ne galibi saboda hulɗar tara π-π da haɗin H.
Tsarin hankali na shaƙar ƙwayoyin cuta na DC ta hanyar haɗakar ƙwayoyin cuta na rGO/nZVI da nZVI (A). FTIR adsorption spectra na DC akan rGO/nZVI da nZVI (B).
Ƙarfin madaurin sha na nZVI a 3244, 1615, 1546, da 1011 cm–1 ya ƙaru bayan shaƙar DC akan nZVI (Hoto na 10B) idan aka kwatanta da nZVI, wanda ya kamata ya kasance yana da alaƙa da hulɗa da ƙungiyoyin aiki na ƙungiyoyin carboxylic acid O a DC. Duk da haka, wannan ƙaramin kashi na watsawa a cikin duk madaurin da aka lura yana nuna babu wani canji mai mahimmanci a cikin ingancin shaƙar phytosynthetic adsorbent (nZVI) idan aka kwatanta da nZVI kafin tsarin shaƙar. A cewar wani bincike na cire DC tare da nZVI71, lokacin da nZVI ya yi hulɗa da H2O, ana sakin electrons sannan ana amfani da H+ don samar da hydrogen mai aiki mai ragewa sosai. A ƙarshe, wasu mahaɗan cationic suna karɓar electrons daga hydrogen mai aiki, wanda ke haifar da -C=N da -C=C-, wanda aka danganta da rabuwar zoben benzene.
Lokacin Saƙo: Nuwamba-14-2022