Graphite yakakamurwa kuita graphite yekugadzira uye graphite yechisikigo, matura egraphite yechisikigo akavonekwa pasi rose muhuwandu hwematani angangoita mabhiriyoni maviri.
Graphite yekugadzira inowanikwa nekuora nekupisa zvinhu zvine kabhoni pasi pekumanikidzwa kwakajairika. Kuchinja uku kunoda tembiricha yakakwana nesimba sesimba rinokutungamirira, uye chimiro chisina kurongeka chichashandurwa kuita chimiro chekristaro chegraphite chakarongeka.
Graphitization iri mupfungwa yakakura yezvinhu zvecarbonaceous kuburikidza nekupisa kwakanyanya kupisa kwepamusoro pe2000 ℃ kurapwa kwemaatomu ecarbon rearrangement, zvisinei, zvimwe zvinhu zvecarbon zviri mukupisa kwakanyanya pamusoro pe3000 ℃ graphitization, rudzi urwu rwezvinhu zvecarbon rwaizivikanwa se "charcoal yakaoma", kuti zvive nyore kushandisa graphitized carbon materials, nzira ye graphitization yechinyakare inosanganisira tembiricha yakakwira uye nzira yekumanikidza yakakwira, catalytic graphitization, chemical vapor deposition method, nezvimwewo.
Kugadzira girafiti inzira inoshanda yekushandisa zvinhu zvine kabhoni zvakanyanya. Mushure mekutsvagurudza kwakadzama nenyanzvi, yakura izvozvi. Zvisinei, zvimwe zvinhu zvisina kunaka zvinoganhurira kushandiswa kwegirafiti yechinyakare mumaindasitiri, saka inzira isingadzivisike yekutsvaga nzira itsva dzekugadzira girafiti.
Nzira ye electrolysis yemunyu wakanyungudutswa kubvira muzana remakore rechi19 yaive nemakore anopfuura zana ekukura, dzidziso yayo huru uye nzira itsva dzinogara dziri hunyanzvi nekukura, ikozvino haisisiri kungogumira kuindasitiri yesimbi yechinyakare, pakutanga kwezana remakore rechi21, gadziriro yesimbi muhurongwa hwemunyu wakanyungudutswa ye solid oxide electrolytic reduction yesimbi dze elemental yave chinhu chinonyanya kukosha mune zvakanyanya kushanda,
Munguva pfupi yapfuura, nzira itsva yekugadzira zvinhu zvegrafiti ne electrolysis yemunyu wakanyungudutswa yakakwezva vanhu vakawanda.
Nekushandisa cathodic polarization uye electrodeposition, mhando mbiri dzakasiyana dzezvinhu zvekabhoni zvinoshandurwa kuita zvinhu zve nano-graphite zvine kukosha kwakanyanya. Kana zvichienzaniswa netekinoroji yechinyakare yegraphitization, nzira itsva yegraphitization ine zvakanakira zvekudzikira kwekushisa kwegraphitization uye morphology inodzoreka.
Pepa iri rinoongorora kufambira mberi kwegraphitization nenzira ye electrochemical, rinounza tekinoroji iyi itsva, rinoongorora zvakanakira nezvayakaipira, uye rinotarisira mafambiro ayo ekuvandudza mune ramangwana.
Chekutanga, nzira yekupolarization yemunyu wakanyungudutswa electrolytic cathode
1.1 zvinhu zvakagadziriswa
Parizvino, zvinhu zvikuru zvekugadzira graphite i-needle coke nepitch coke zvine dhigirii repamusoro re graphitization, kureva kuti, mafuta akasara uye marasha etara sezvinhu zvakagadzirwa kuti zvigadzire zvinhu zvemhando yepamusoro zvekabhoni, zvine porosity yakaderera, sarufa yakaderera, dota shoma uye zvakanakira zve graphitization, mushure mekugadzirira kwayo kuita graphite ine kuramba kwakanaka kwekurova, simba guru remuchina, resistivity yakaderera,
Zvisinei, kushaikwa kwemafuta akachengetwa pamwe nemitengo yemafuta iri kuchinja-chinja zvakaderedza kukura kwayo, saka kutsvaga zvinhu zvitsva kwave dambudziko rinoda kugadziriswa nekukurumidza.
Nzira dzechinyakare dzekugadzira girafiti dzine miganhu, uye nzira dzakasiyana dzekugadzira girafiti dzinoshandisa zvinhu zvakasiyana. Kune kabhoni isina girafiti, nzira dzechinyakare hadzigone kuigadzira girafiti, nepo fomura yemagetsi yemunyu wakanyungudutswa inopinda muganho wezvinhu zvakacheneswa, uye yakakodzera kune zvese zvinhu zvekabhoni zvechinyakare.
Zvinhu zvekabhoni zvechinyakare zvinosanganisira kabhoni nhema, kabhoni yakakangwa, marasha, nezvimwewo, pakati pazvo marasha ndiwo anonyanya kuvimbisa. Inki yakagadzirwa nemarasha inotora marasha senzira yekutanga uye inogadzirwa kuita zvigadzirwa zvegrafiti pakupisa kwakanyanya mushure mekugadzirisa.
Munguva pfupi yapfuura, bepa iri rinokurudzira nzira itsva dze electrochemical, dzakadai sePeng, ne electrolysis yemunyu wakanyungudutswa hazvigoneke kuti graphitized kabhoni nhema ipinde mu crystallinity yakakura ye graphite, electrolysis yemasampuli e graphite ane petal shape graphite nanometer chips, ine nzvimbo yepamusoro chaiyo, kana ikashandiswa ye lithium battery cathode yakaratidza kushanda kwakanaka kwe electrochemical kupfuura natural graphite.
Zhu nevamwe vake vakaisa marasha asina kunaka akagadziriswa muCaCl2 mold salt system kuti ishandiswe pa 950 ℃, uye vakabudirira kushandura marasha asina kunaka kuita graphite ine crystallinity yakakura, iyo yakaratidza kushanda zvakanaka uye hupenyu hwenguva refu kana ikashandiswa seanode yebhatiri re lithium ion.
Kuedza uku kunoratidza kuti zvinokwanisika kushandura mhando dzakasiyana dzezvinhu zvekabhoni zvechinyakare kuita graphite kuburikidza neelectrolysis yemunyu wakanyungudutswa, izvo zvinovhura nzira itsva yegirafiti yekugadzira mune ramangwana.
1.2 mashandiro e
Nzira ye electrolysis yemunyu wakanyungudutswa inoshandisa zvinhu zvekabhoni se cathode uye inoishandura kuita graphite ine crystallinity yakakwira kuburikidza ne cathodic polarization. Parizvino, mabhuku aripo anotaura nezve kubviswa kweokisijeni uye kugadziriswazve kwemaatomu ekabhoni kure kure mukuchinja kunogona kuitika kwe cathodic polarization.
Kuvapo kweokisijeni muzvinhu zvekabhoni kunokanganisa kugadzirwa kwegirafiti kusvika pamwero wakati. Mukuita kwegirafiti, okisijeni inobviswa zvishoma nezvishoma kana tembiricha yakwira kupfuura 1600K. Zvisinei, zviri nyore kwazvo kubvisa okisijeni kuburikidza ne cathodic polarization.
Peng, nezvimwewo mukuyedza kekutanga vakaisa pamberi nzira yekunyungudutswa kwemunyu electrolysis cathodic polarization potential mechanism, kureva kuti graphitization inonyanya kutanga iri munzvimbo yakasimba yekabhoni microspheres/electrolyte interface, kutanga kabhoni microsphere inoumba yakakomberedza ganda regirafu regirafu rimwe chete, uye ipapo maatomu ekabhoni kabhoni asingagadzike anopararira kune girafu rekunze rakagadzikana, kusvika ranyatsogadzirwa.
Maitiro ekugadzira graphitization anoperekedzwa nekubviswa kweokisijeni, izvo zvinosimbiswawo nekuyedza.
Jin nevamwe vake vakaratidzawo maonero aya kuburikidza nekuyedza. Mushure mekuiswa kweglucose mu carbonization, graphitization (17% oxygen content) yakaitwa. Mushure mekuiswa kwegraphitization, ma solid carbon sphere ekutanga (Mufananidzo 1a na 1c) akaumba goko rine maburi rakaumbwa ne graphite nanosheets (Mufananidzo 1b na 1d).
Nekushandisa electrolysis ye carbon fibers (16% okisijeni), carbon fibers dzinogona kushandurwa kuita machubhu e graphite mushure me graphitization zvichienderana nemaitiro ekushandura anofungidzirwa mumabhuku.
Vaidavira kuti kufamba kure kuri pasi pe cathodic polarization yemaatomu ekabhoni, iyo high crystal graphite kusvika amorphous carbon rearrange inofanira kugadziriswa, graphite yakagadzirwa ine petals yakasiyana ine nanostructures dzakabatsirwa nemaatomu eokisijeni kubva, asi maitiro chaiwo ekuchinja graphite nanometer structure haana kujeka, akadai se oxygen kubva kumatafura ekabhoni mushure mekuita cathode, nezvimwewo.
Parizvino, tsvakiridzo pamusoro pemuchina uyu ichiri padanho rekutanga, uye tsvakiridzo yakawedzerwa inodiwa.
1.3 Kutsanangurwa kwechimiro chegraphite yakagadzirwa
SEM inoshandiswa kuona morphology yepamusoro pe graphite iri pasi pe microscopic, TEM inoshandiswa kuona structural morphology iri pasi pe 0.2 μm, XRD uye Raman spectroscopy ndiyo nzira inonyanya kushandiswa kuratidza microstructure ye graphite, XRD inoshandiswa kuratidza crystal information ye graphite, uye Raman spectroscopy inoshandiswa kuratidza zvikanganiso uye order degree ye graphite.
Kune maburi akawanda mugraphite anogadzirwa ne cathode polarization ye molten salt electrolysis. Kune zvinhu zvakasiyana-siyana, zvakaita se carbon black electrolysis, ma nanostructures akafanana ne petal-like porous anowanikwa. XRD ne Raman spectrum analysis zvinoitwa pa carbon black mushure me electrolysis.
Pa 827 ℃, mushure mekubatwa ne 2.6V voltage kwe 1 awa, mufananidzo weRaman spectral we carbon black unenge wakafanana newe commercial graphite. Mushure mekunge carbon black yabatwa nekupisa kwakasiyana, sharp graphite characteristic peak (002) inoyerwa. Diffraction peak (002) inomiririra mwero we aromatic carbon layer mu graphite.
Kana kabhoni yakapinza, ndipo painotaridzika zvakanyanya.
Zhu akashandisa marasha asina kucheneswa se cathode mukuyedza, uye chimiro che microstructure chechigadzirwa che graphitized chakachinjwa kubva pa granular kuita chimiro chikuru che graphite, uye tight graphite layer yakaonekwawo pasi pe high rate transmission electron microscope.
MuRaman spectra, nekuchinja kwemamiriro ekuyedza, kukosha kweID/Ig kwakachinjawo. Kana tembiricha ye electrolytic yaive 950 ℃, nguva ye electrolytic yaive 6h, uye voltage ye electrolytic yaive 2.6V, kukosha kweID/Ig kwakaderera kwaive 0.3, uye D peak yaive yakaderera zvakanyanya pane G peak. Panguva imwe chete, kuoneka kwe2D peak kwaimiririrawo kuumbwa kwechimiro chegraphite chakarongeka zvakanyanya.
Kupenya kwakapinza (002) kwe diffraction mumufananidzo weXRD kunosimbisawo kushandurwa kwakabudirira kwemarasha asina simba kuita graphite ane crystallinity yakakwira.
Mukuita graphitization, kuwedzera kwekupisa uye voltage kuchaita basa rekusimudzira, asi voltage yakawandisa inoderedza goho regraphite, uye tembiricha yakakwira kana nguva yakareba yegraphitization inotungamira mukurasikirwa kwezviwanikwa, saka kune zvakasiyana-siyana zvekabhoni, zvakakosha zvikuru kuongorora mamiriro emagetsi akakodzera, ndiyo zvakare pfungwa uye kuoma.
Iyi nanostructure yakaita sepetal ine electrochemical properties yakanaka kwazvo. Maburi akawanda anobvumira maion kuti apinzwe/abviswe nekukurumidza, zvichipa zvinhu zve cathode zvemhando yepamusoro zvemabhatiri, nezvimwewo. Saka, electrochemical method graphitization inzira inogona kushandiswa zvakanyanya pa graphitization.
Nzira yekumisikidza electrode yemunyu wakanyungudutswa
2.1 Kuiswa kweElectrode kwecarbon dioxide
Segasi rinopisa zvakanyanya, CO2 imhepo isingakuvadzi, isingakuvadzi, yakachipa uye inowanikwa nyore nyore. Zvisinei, kabhoni iri muCO2 iri mumamiriro ekupisa akanyanya, saka CO2 ine kugadzikana kwakanyanya kwethermodynamic, izvo zvinoita kuti zviome kushandisa zvakare.
Tsvagiridzo yekutanga pamusoro pekuiswa kwemagetsi eCO2 inogona kuteverwa kumashure kusvika kuma1960. Ingram nevamwe vake vakabudirira kugadzira electrode yekabhoni pagoridhe muhurongwa hwemunyu wakanyungudutswa weLi2CO3-Na2CO3-K2CO3.
Van nevamwe vake vakataura kuti hupfu hwekabhoni hwakawanikwa pamatanho akasiyana ekuderedza hune maumbirwo akasiyana, anosanganisira graphite, amorphous carbon uye carbon nanofibers.
Nekushandisa munyu wakanyungudutswa kubata CO2 uye nzira yekugadzirira kubudirira kwezvinhu zvekabhoni, mushure menguva refu yekutsvagurudza nyanzvi dzakatarisa pakugadzira kabhoni uye mhedzisiro yemamiriro emagetsi pakugadzirwa kwekupedzisira, ayo anosanganisira tembiricha yemagetsi, voltage yemagetsi uye kuumbwa kwemunyu wakanyungudutswa nemaelectrode, nezvimwewo, kugadzirira kushanda kwepamusoro kwezvinhu zvegraphite zvekuisa CO2 pamagetsi kwave nehwaro hwakasimba.
Nekuchinja electrolyte uye kushandisa CaCl2-based moldured salt system ine CO2 capture efficiency yakakwira, Hu nevamwe vakabudirira kugadzira graphene ine graphitization degree yakakwira uye carbon nanotubes nedzimwe nanographite structures nekudzidza mamiriro e electrolytic akadai se electrolysis temperature, electrode composition uye moldured salt composition.
Kana tichienzanisa ne carbonate system, CaCl2 ine zvakanakira zvekuti haina mari yakawanda uye iri nyore kuwana, ine conductivity yakawanda, iri nyore kunyungudika mumvura, uye ine oxygen ions yakawanda inonyungudika, izvo zvinopa mamiriro edzidziso ekushandura CO2 kuita zvigadzirwa zve graphite zvine kukosha kwakanyanya.
2.2 Maitiro ekushandura
Kugadzirwa kwezvinhu zvine kabhoni yakawanda nekuisa CO2 kubva mumunyu wakanyungudutswa kunosanganisira kubata CO2 uye kuderedza zvisina kunanga. Kubata CO2 kunozadziswa nemunyu wakanyungudutswa weO2- wakasununguka, sezvakaratidzwa muEquation (1):
CO2+O2-→CO3 2- (1)
Parizvino, nzira nhatu dzekuderedza zvisina kunanga dzakarongwa: reaction yedanho rimwe chete, reaction yedanho rimwe chete uye reaction yekuderedza simbi.
Maitiro ekuita chimwe chete akatanga kutaurwa naIngram, sezvakaratidzwa muEquation (2):
CO3 2-+ 4E – →C+3O2- (2)
Maitiro ekuita zvinhu nenzira mbiri akakurudzirwa naBorucka nevamwe vake, sezvakaratidzwa muEquation (3-4):
CO3 2-+ 2E – →CO2 2-+O2- (3)
CO2 2-+ 2E – →C+2O2- (4)
Maitiro ekuderedza simbi akataurwa naDeanhardt nevamwe vake. Vaitenda kuti maion esimbi aitanga aderedzwa kuita simbi mu cathode, uye simbi yacho yakadzikiswa kuita maion e carbonate, sezvakaratidzwa muEquation (5~6):
M- + E – →M (5)
4 m + M2CO3 – > C + 3 m2o (6)
Parizvino, nzira yekuita chimwe chinhu nenzira imwe chete inogamuchirwa mumabhuku aripo.
Yin nevamwe vake vakadzidza Li-Na-K carbonate system ine nickel se cathode, tin dioxide se anode uye silver wire se reference electrode, uye vakawana cyclic voltammetry test figure iri muMufananidzo 2 (scanning rate ye100 mV/s) pa nickel cathode, uye vakaona kuti paive ne reduction peak imwe chete (pa -2.0V) mu negative scanning.
Saka, zvinogona kugumiswa kuti mhinduro imwe chete yakaitika panguva yekuderedzwa kwecarbonate.
Gao nevamwe vake vakawana cyclic voltammetry yakafanana mune imwecheteyo carbonate system.
Ge nevamwe vake vakashandisa anode isina simba uye tungsten cathode kubata CO2 muLiCl-Li2CO3 system uye vakawana mifananidzo yakafanana, uye kuderedzwa kwehuwandu hwecarbon deposition kwakaonekwa chete mu negative scanning.
Mumushonga wemunyu wakanyungudutswa wesimbi ine alkaline, simbi dzine alkali neCO2 zvinogadzirwa ukuwo kabhoni ichiiswa ne cathode. Zvisinei, nekuti mamiriro e thermodynamic e carbon deposition reaction akaderera patembiricha yakaderera, kuderedzwa kwe carbonate kuita kabhoni chete ndiko kunogona kuonekwa mukuyedza.
2.3 Kubatwa kweCO2 nemunyu wakanyungudutswa kugadzira zvigadzirwa zvegrafiti
Zvinhu zve graphite zvine mutengo wakakwira zvakaita se graphene ne carbon nanotubes zvinogona kugadzirwa ne electrodeposition ye CO2 kubva mumunyu wakanyungudutswa nekudzora mamiriro ekuyedza. Hu nevamwe vakashandisa simbi isina ngura se cathode muCaCl2-NaCl-CaO molded salt system uye vakaisa electrolyze kwemaawa mana pasi pe 2.6V constant voltage patembiricha dzakasiyana.
Nekuda kwekugadziriswa kwesimbi uye kuputika kweCO2 pakati pezvikamu zvegraphite, graphene yakawanikwa pamusoro pe cathode. Maitiro ekugadzirira graphene anoratidzwa muMufananidzo 3.
Mufananidzo wacho
Zvidzidzo zvakazotevera zvakawedzera Li2SO4 zvichibva paCaCl2-NaClCaO yakanyungudutswa munyu, tembiricha ye electrolysis yaive 625 ℃, mushure memaawa mana e electrolysis, panguva imwe chete mu cathodic deposition ye carbon yakawanikwa graphene uye carbon nanotubes, chidzidzo chakawana kuti Li+ uye SO4 2- zvinounza mhedzisiro yakanaka pa graphitization.
Sarufa inobatanidzwawo zvinobudirira mumuviri wekabhoni, uye mapepa egrafiti akatetepa zvakanyanya uye kabhoni ine filamentous zvinogona kuwanikwa nekudzora mamiriro emagetsi.
Zvinhu zvakadai sekupisa kwe electrolytic kwepamusoro nepasi kwe graphene zvakakosha, kana tembiricha iri pamusoro pe 800 ℃ iri nyore kugadzira CO panzvimbo pe kabhoni, inenge isina kabhoni yakawanda kana iri pamusoro pe 950 ℃, saka kudzora tembiricha kwakakosha zvikuru kugadzira graphene ne carbon nanotubes, uye kudzorera kudiwa kwe carbon deposition reaction CO reaction synergy kuti cathode igadzire graphene yakagadzikana.
Mabasa aya anopa nzira itsva yekugadzira zvigadzirwa zve nano-graphite neCO2, iyo inokosha zvikuru pakugadziriswa kwemagasi egreenhouse uye kugadzirira graphene.
3. Pfupiso uye Maonero
Nekukura kuri kuita indasitiri itsva yesimba, girafiti yechisikigo haina kukwanisa kusangana nezvinodiwa pari zvino, uye girafiti yekugadzira ine hunhu huri nani hwemuviri nemakemikari pane girafiti yechisikigo, saka girafiti yakachipa, inoshanda uye ine hushamwari kune zvakatipoteredza chinangwa chenguva refu.
Nzira dzemagetsi dzekugadzira graphitization muzvinhu zvakasimba uye zvegasi nenzira ye cathodic polarization uye electrochemical deposition yakabudirira kubva muzvinhu zve graphite zvine kukosha kwakanyanya, zvichienzaniswa nenzira yechinyakare ye graphitization, nzira ye electrochemical inoshanda zvakanyanya, kushandiswa kwesimba kwakaderera, kuchengetedzwa kwezvakatipoteredza kwakasvibirira, kune zvinhu zvidiki zvinosarudzwa panguva imwe chete, zvichienderana nemamiriro akasiyana e electrolysis anogona kugadzirwa pamhando dzakasiyana dze graphite structure,
Inopa nzira inoshanda yekuti marudzi ese emagasi asina chimiro uye magasi egreenhouse ashandurwe kuita zvinhu zvakakosha zvegrafiti uye ine mukana wakanaka wekushandiswa.
Parizvino, tekinoroji iyi ichiri kutanga. Kune zvidzidzo zvishoma pamusoro pekugadzira graphitization nenzira ye electrochemical, uye kuchine maitiro akawanda asingazivikanwe. Nokudaro, zvakakosha kutanga nezvinhu zvakagadziriswa uye kuita chidzidzo chakakwana uye chakarongeka pamakabhoni akasiyana-siyana asina chimiro, uye panguva imwe chete kuongorora thermodynamics uye simba rekushandurwa kwegraphite zvakadzama.
Izvi zvine kukosha kukuru mukukura kweindasitiri yegraphite mune ramangwana.
Nguva yekutumira: Chivabvu-10-2021