Graphite yakakamurwa kuita artificial graphite uye Natural graphite, iyo inochengeterwa pasi rose yezvakasikwa graphite mumatani anosvika mabhiriyoni maviri.
Artificial graphite inowanikwa nekuparara uye kupisa kupisa kwezvinhu zvine kabhoni pasi pekumanikidzwa kwakajairwa. Shanduko iyi inoda tembiricha yakakwana uye simba sesimba rekutyaira, uye chimiro chakakanganisika chinozoshandurwa kuita yakarongedzerwa graphite crystal chimiro.
Graphitization iri mune yakafara pfungwa yecarbonaceous zvinhu kuburikidza nepamusoro pe2000 ℃ yakanyanya tembiricha yekupisa kabhoni maatomu rearrangement, zvisinei zvimwe kabhoni mune yakanyanya tembiricha iri pamusoro pe3000 ℃ graphitization, rudzi urwu rwekabhoni rwaizivikanwa se "marasha akaomarara", kuitira nyore graphitized kabhoni maatomu, iyo yechinyakare graphitization yakakwira tembiricha nzira, yakakwira graphit uye nzira yekumanikidza yemakemikari. deposition nzira, nezvimwewo.
Graphitization inzira inoshanda yekuwedzera kukosha kwekushandisa kwezvinhu zvekabhoni. Mushure mekutsvagisa kwakadzama uye kwakadzama nenyanzvi, yatokura izvozvi. Nekudaro, zvimwe zvinhu zvisingafadzi zvinomisa kushandiswa kwechinyakare graphitization muindasitiri, saka itsika isingadzivisike yekuongorora nzira nyowani dzegraphitization.
Yakanyungudutswa munyu electrolysis nzira kubva muzana ramakore rechi 19 yaive inopfuura zana yebudiriro, dzidziso yayo yekutanga uye nzira nyowani dzinogara dzichivandudza uye budiriro, ikozvino haichaganhurirwe kune yechinyakare metallurgical indasitiri, pakutanga kwezana ramakore rechi21, iyo simbi muyakanyungudutswa munyu system solid oxide electrolytic kuderedza kugadzirira kwekutanga simbi kwave kutariswa mune yakanyanya kushanda,
Munguva ichangopfuura, nzira itsva yekugadzira magirafu zvinhu neyakanyungudutswa munyu electrolysis yakwezva vanhu vakawanda.
Kuburikidza necathodic polarization uye electrodeposition, iyo miviri yemhando dzakasiyana dzekabhoni raw materials inoshandurwa kuita nano-graphite zvinhu zvine kukosha kwakawedzera. Kuenzaniswa neyechinyakare graphitization tekinoroji, iyo itsva graphitization nzira ine zvakanakira yakaderera graphitization tembiricha uye controllable morphology.
Iri bepa rinoongorora kufambira mberi kwegraphitization ne electrochemical nzira, inosuma iyi tekinoroji nyowani, inoongorora zvayakanakira nezvayakaipira, uye inotarisira maitiro ayo emangwana ebudiriro.
Kutanga, yakanyungudutswa munyu electrolytic cathode polarization nzira
1.1 zvinhu zvakasara
Parizvino, iyo huru yakabikwa yeartificial graphite ndeye tsono coke uye pitch coke yeyakakwira graphitization degree, iyo yakasara yemafuta uye marasha tara seyakagadzirwa kugadzira yakakwira mhando kabhoni zvinhu, ine yakaderera porosity, yakaderera sarufa, yakaderera madota uye zvakanakira graphitization, mushure mekugadzirira kwayo mugraphite, kushomeka kwesimba, kushomeka kwesimba, kushomeka kwemagetsi, kusimba kwesimba, kushomeka kwemagetsi.
Nekudaro, mafuta mashoma akachengetwa uye mitengo yemafuta iri kudonha yakaganhurira kukura kwayo, saka kutsvaga zvigadzirwa zvitsva rave dambudziko rekukurumidza kugadziriswa.
Tsika dzechinyakare graphitization nzira dzine painogumira, uye dzakasiyana graphitization nzira dzinoshandisa akasiyana mbishi zvinhu. Kune isina-graphitized kabhoni, nzira dzechinyakare hadzingaite graphitize, nepo electrochemical formula yeyakanyungudutswa munyu electrolysis inotyora nekudzikiswa kwezvinhu, uye inokodzera zvinenge zvese zvechinyakare kabhoni zvinhu.
Zvechinyakare kabhoni zvinhu zvinosanganisira kabhoni dema, activated kabhoni, marasha, nezvimwewo, pakati peiyo marasha ndiyo inonyanya kuvimbisa. Iyo inki-yakavakirwa marasha inotora marasha seanotangira uye inogadzirirwa kuita zvigadzirwa zvegraphite pakupisa kwakanyanya mushure mekutanga kurapwa.
Munguva ichangopfuura, bepa rino proposes itsva electrochemical nzira, dzakadai Peng, neyakanyungudutswa munyu electrolysis haigoni graphitized kabhoni dema kupinda yakakwirira crystallinity of graphite, electrolysis of graphite samples ane petal chimiro graphite nanometer chips, ane yakakwirira chaiyo pamusoro nzvimbo, apo inoshandiswa kuti lithium bhatiri cathode yakaratidza kunaka electrochemical kushanda kupfuura dzinongoitika girafu.
Zhu et al. isa deashing yakabatwa yakaderera-mhando marasha muCaCl2 yakanyungudutswa munyu system ye electrolysis pa 950 ℃, uye yakabudirira kushandura yakaderera-mhando marasha kuita graphite ine yakakwira crystallinity, iyo yakaratidza kuita kwakanaka kwekuita uye hupenyu hurefu hwekutenderera pakashandiswa seanode ye lithium ion bhatiri.
Kuedza kwacho kunoratidza kuti zvinogoneka kushandura mhando dzakasiyana dzechinyakare kabhoni kuita graphite nenzira yakanyungudutswa yemunyu electrolysis, iyo inovhura nzira nyowani yeramangwana rekugadzira graphite.
1.2 nzira ye
Melten salt electrolysis method inoshandisa kabhoni secathode uye inoishandura kuita graphite ine high crystallinity nenzira ye cathodic polarization. Parizvino, mabhuku aripo anotaura nezvekubviswa kweokisijeni uye kureba kurebazve kwekabhoni maatomu mune inogona kutendeuka nzira ye cathodic polarization.
Kuvapo kweokisijeni mune kabhoni zvinhu kunotadzisa graphitization kune imwe nhanho. Muchinyakare graphitization process, okisijeni inozobviswa zvishoma nezvishoma kana tembiricha yakakwira kupfuura 1600K. Nekudaro, zvakanyanya nyore kuita deoxidize kuburikidza necathodic polarization.
Peng, nezvimwe mukuedza kekutanga kuisa pamberi yakanyungudutswa munyu electrolysis cathodic polarization inogona mashandiro, kureva graphitization kazhinji nzvimbo yekutanga inofanira kuwanikwa mune yakasimba kabhoni microspheres / electrolyte interface, yekutanga kabhoni microsphere fomu yakatenderedza yakaenzana dhayamita graphite goko, uyezve isingambogadzika anhydrous kabhoni kabhoni maatomu apararira kusvika akanyanya kugadzikana.
Iyo graphitization process inoperekedzwa nekubviswa kweokisijeni, iyo inosimbiswa zvakare nemiedzo.
Jin et al. yakaratidzawo pfungwa iyi kuburikidza nekuedza. Mushure mecarbonization yeglucose, graphitization (17% okisijeni yemukati) yakaitwa. Mushure me graphitization, iyo yepakutanga yakasimba carbon spheres (Fig. 1a uye 1c) yakagadzira ganda rinoputika rinoumbwa ne graphite nanosheets (Fig. 1b uye 1d).
Ne electrolysis yekabhoni fibers (16% okisijeni), iyo kabhoni fibers inogona kushandurwa kuita graphite machubhu mushure me graphitization maererano neshanduko nzira inofungidzirwa mumabhuku.
Zvinotendwa kuti, kureba kwekufamba kuri pasi pe cathodic polarization yekabhoni maatomu iyo yakakwira crystal graphite kune amorphous kabhoni rearrange inofanirwa kugadzirisa, synthetic graphite yakasarudzika petals chimiro nanostructures yakabatsirwa nemaatomu eokisijeni kubva, asi iyo chaiyo nzira yekupesvedzera graphite nanometer chimiro haina kujeka, senge okisijeni kubva kabhoni skelede mushure mekuita sei, nezvimwe.
Parizvino, tsvakiridzo pamusoro pemashini ichiri mudanho rekutanga, uye kumwe kutsvagisa kunodiwa.
1.3 morphological maitiro ekugadzira graphite
SEM inoshandiswa kuona iyo microscopic surface morphology yegraphite, TEM inoshandiswa kutarisa morphology yemaitiro isingasviki 0.2 μm, XRD neRaman spectroscopy ndiyo inonyanya kushandiswa nzira kuratidza microstructure yegraphite, XRD inoshandiswa kuratidza ruzivo rwekristaro rwegraphite, uye Raman inoshandiswa kuodha dhigirii redhigirii.
Kune akawanda ma pores mu graphite yakagadzirwa ne cathode polarization ye yakanyungudutswa munyu electrolysis. Kune akasiyana mbishi zvinhu, senge kabhoni dema electrolysis, petal-senge porous nanostructures inowanikwa. XRD uye Raman spectrum ongororo inoitwa pane kabhoni nhema mushure me electrolysis.
Pa827 ℃, mushure mekurapwa ne 2.6V voltage ye 1h, mufananidzo weRaman wekabhoni dema wakada kufanana newekutengesa graphite. Mushure mekunge kabhoni dema yabatwa nekudziya kwakasiyana, iyo inopinza graphite maitiro peak (002) inopimwa. Iyo diffraction peak (002) inomiririra dhigirii rekutarisa kweiyo inonhuhwirira kabhoni layer mugraphite.
Iyo yakanyanya kupinza kabhoni layer, iyo yakanyanya kutarisisa.
Zhu akashandisa marasha akacheneswa akaderera secathode mukuedza, uye microstructure yechigadzirwa che graphiti yakashandurwa kubva kugranular kusvika kuhombe yegirafu chimiro, uye iyo yakasimba girafu layer yakaonekwa zvakare pasi pepamusoro-soro yekufambisa electron maikorosikopu.
MuRaman spectra, neshanduko yemamiriro ekuyedza, iyo ID / Ig kukosha yakachinjawo. Apo tembiricha ye electrolytic yaive 950 ℃, nguva ye electrolytic yaive 6h, uye electrolytic voltage yaive 2.6V, yakaderera ID/Ig kukosha yaive 0.3, uye D peak yaive yakaderera zvakanyanya pane G peak. Panguva imwecheteyo, kutaridzika kwe2D peak zvakare kwakamiririra kuumbwa kweiyo yakanyanya kurongeka graphite chimiro.
Iyo inopinza (002) diffraction peak mumufananidzo weXRD inosimbisawo kubudirira kushandurwa kwemarasha akaderera kuita graphite ine yakakwirira crystallinity.
Mukuita graphitization, kuwedzera kwekushisa uye voltage kuchaita basa rekusimudzira, asi yakawandisa voltage inoderedza goho regraphite, uye yakanyanyisa tembiricha kana yakareba graphitization nguva inotungamira mukuraswa kwezviwanikwa, saka kune akasiyana kabhoni zvinhu, zvinonyanya kukosha kuongorora akanyanya kukodzera mamiriro e electrolytic, ndikowo kutarisa uye kuoma.
Iyi petal-senge flake nanostructure ine yakanakisa electrochemical zvimiro. Nhamba huru ye pores inobvumira ions kuti ikurumidze kuiswa / kuvharwa, ichipa yakakwirira-yepamusoro cathode zvinhu zvemabhatiri, etc. Nokudaro, electrochemical method graphitization inonyatsogona graphitization nzira.
Yakanyungudutswa munyu electrodeposition nzira
2.1 Electrodeposition yecarbon dioxide
Seyakanyanya kukosha gasi regreenhouse, CO2 zvakare isiri-chepfu, isingakuvadzi, yakachipa uye inowanikwa zviri nyore renewable sosi. Nekudaro, kabhoni iri muCO2 iri munzvimbo yepamusoro oxidation, saka CO2 ine yakakwira thermodynamic kugadzikana, izvo zvinoita kuti zviome kushandisa zvakare.
Tsvagiridzo yekutanga paCO2 electrodeposition inogona kurondwa kumashure kuma1960s. Ingram et al. zvakabudirira kugadzirira kabhoni pane electrode yegoridhe mune yakanyungudutswa munyu system yeLi2CO3-Na2CO3-K2CO3.
Van et al. yakaratidza kuti iyo kabhoni poda yakawanikwa pamhando dzakasiyana dzekudzikisa yaive nezvimiro zvakasiyana, zvinosanganisira graphite, amorphous kabhoni uye kabhoni nanofibers.
Nemunyu wakanyungudutswa kutora CO2 uye nzira yekugadzirira yekubudirira kwekabhoni zvinhu, mushure menguva yakareba yekutsvagisa nyanzvi dzakatarisa pane kabhoni deposition kugadzira meshini uye mhedzisiro yemamiriro e electrolysis pachigadzirwa chekupedzisira, zvinosanganisira tembiricha ye electrolytic, electrolytic voltage uye kuumbwa kwemunyu wakanyunguduka uye maelectrodes, nezvimwewo, kugadzirira kwepamusoro kuita kwegraphite zvinhu zve electrodeposition yeCO2 yakateya nheyo yakasimba.
Nekushandura electrolyte uye kushandisa CaCl2-yakanyungudutswa munyu system ine yakakwira CO2 kubatwa zvakanaka, Hu et al. zvakabudirira kugadzirira graphene ine yepamusoro graphitization dhigirii uye kabhoni nanotubes uye zvimwe zvimiro zvenanographite nekudzidza mamiriro e electrolytic senge electrolysis tembiricha, electrode kuumbwa uye yakanyungudutswa munyu.
Kana ichienzaniswa necarbonate system, CaCl2 ine zvakanakira zvekuchipa uye zviri nyore kuwana, yakakwirira conductivity, nyore kunyungudika mumvura, uye kunyungudika kweokisijeni ion, izvo zvinopa mamiriro edzidziso yekushandurwa kweCO2 kuita zvigadzirwa zvegraphite zvine kukosha kwakawedzera.
2.2 Shanduko Mechanism
Kugadzirira kwepamusoro kukosha-yakawedzerwa kabhoni zvinhu ne electrodeposition ye CO2 kubva munyu yakanyungudutswa inonyanya kusanganisira CO2 kubatwa uye kuderedzwa kusina kunanga. Kutorwa kweCO2 kunopedzwa nemahara O2- mumunyu wakanyungudutswa, sezvinoratidzwa muEquation (1) :
CO2+O2-→CO3 2- (1)
Parizvino, nzira nhatu dzisina kunanga dzekudzikisa maitiro dzakatsanangurwa: nhanho imwe-nhanho, maviri-nhanho maitiro uye simbi yekudzikisa maitiro maitiro.
Iyo nhanho-yekuita maitiro yakatanga kukurudzirwa naIngram, sezvakaratidzwa muEquation (2):
CO3 2-+ 4E – →C+3O2- (2)
Maitiro maviri-matanho ekuita akakurudzirwa naBorucka et al., sezvakaratidzwa muEquation (3-4):
CO3 2-+ 2E – →CO2 2-+O2- (3)
CO2 2-+ 2E – →C+2O2- (4)
Iyo nzira yekudzikisa simbi yekuita yakatsanangurwa naDeanhardt et al. Vaitenda kuti iyoni yesimbi yakatanga kuderedzwa kuita simbi mu cathode, uyezve simbi yakaderedzwa kuita carbonate ion, sezvinoratidzwa muEquation (5~6) :
M- + E – →M (5)
4 m + M2CO3 – > C + 3 m2o (6)
Parizvino, danho rimwe rekuita maitiro rinowanzogamuchirwa mumabhuku aripo.
Yin et al. akadzidza Li-Na-K carbonate system ine nickel se cathode, tin dioxide seanode uye sirivheri waya sereferensi electrode, uye akawana iyo cyclic voltammetry test figure iri muFigure 2 (scanning rate ye100 mV/s) panickel cathode, ndokuona kuti paingova nepeak imwe chete yekudzikisa (pa -2.0V) mu negative scanning.
Nokudaro, zvinogona kugumiswa kuti chiitiko chimwe chete chakaitika panguva yekuderedza carbonate.
Gao et al. yakawana yakafanana cyclic voltammetry mune imwechete carbonate system.
Get et al. yakashandisa inert anode uye tungsten cathode kutora CO2 muLiCl-Li2CO3 system uye yakawana mifananidzo yakafanana, uye chete kuderedzwa kwepamusoro kwekabhoni deposition kwakaonekwa mune yakaipa scanning.
Mune alkaline simbi yakanyungudutswa munyu system, alkali simbi uye CO inogadzirwa uku kabhoni ichiiswa necathode. Nekudaro, nekuti iyo thermodynamic mamiriro eiyo kabhoni deposition reaction yakadzikira pane yakaderera tembiricha, chete kudzikiswa kwecarbonate kuita kabhoni ndiko kunoonekwa mukuyedza.
2.3 CO2 inobatwa nemunyu wakanyungudutswa kugadzira zvigadzirwa zvegraphite
High-value-added graphite nanomaterials senge graphene uye carbon nanotubes inogona kugadzirwa ne electrodeposition ye CO2 kubva mumunyu wakanyungudutswa nekudzora mamiriro ekuedza. Hu et al. yakashandisa simbi isina simbi se cathode muCaCl2-NaCl-CaO yakanyungudutswa munyu system uye yakanyungudutswa nemagetsi kwe4h pasi pemamiriro e2.6V anogara ari voltage patembiricha dzakasiyana.
Kutenda kune catalysis yesimbi uye kuputika kweCO pakati pegraphite layers, graphene yakawanikwa pamusoro pecathode. Nzira yekugadzirira yegraphene inoratidzwa mumufananidzo 3.
Mufananidzo
Gare gare zvidzidzo zvakawedzera Li2SO4 pahwaro hweCaCl2-NaClCaO yakanyungudutswa munyu system, tembiricha ye electrolysis yaive 625 ℃, mushure me4h ye electrolysis, panguva imwechete mune cathodic deposition yecarbon yakawana graphene uye kabhoni nanotubes, chidzidzo chakawana kuti Li + uye SO4 2- kuunza mhedzisiro yakanaka pagraphit.
Sulfur inobatanidzwawo zvakabudirira mumutumbi wecarbon, uye ultra-thin graphite sheets uye filamentous carbon inogona kuwanikwa nekudzora mamiriro e electrolytic.
Zvinhu zvakadai se electrolytic tembiricha yekumusoro uye yakaderera pakuumbwa kwegraphene yakakosha, kana tembiricha yakakwira kupfuura 800 ℃ iri nyore kugadzira CO pachinzvimbo chekabhoni, inenge isina kabhoni deposition kana yakakwira kupfuura 950 ℃, saka tembiricha yekudzora yakakosha kuburitsa graphene nekabhoni nanotubes, uye kudzoreredza chinodiwa kabhoni deposition reaction CO reaction cathodeji kuti ive nechokwadi chekuti girafu inogoneka.
Aya mabasa anopa nzira itsva yekugadzirira kwe nano-graphite zvigadzirwa neCO2, iyo inokosha zvikuru yekugadzirisa magasi egreenhouse uye kugadzirira graphene.
3. Pfupiso uye Outlook
Nekukurumidza kukura kweindasitiri yesimba idzva, magirafu echisikigo haana kukwanisa kuzadzisa kudiwa kwazvino, uye artificial graphite ine zviri nani zvemuviri uye zvemakemikari zvivakwa kupfuura girafu yechisikigo, saka zvakachipa, zvinobudirira uye zvakatipoteredza graphitization chinangwa chenguva refu.
Electrochemical nzira graphitization mune yakasimba uye gasi zvinhu zvakasvibirira zvine nzira ye cathodic polarization uye electrochemical deposition yakabudirira kunze kweiyo graphite zvinhu zvine yakawedzera kukosha, zvichienzaniswa neyechinyakare nzira yegraphitization, iyo electrochemical nzira ndeyekunyanya kushanda, kuderera kwesimba rekushandisa, girinhi kuchengetedza kwezvakatipoteredza, kune zvidiki zvakaganhurirwa nezvinhu zvakasarudzwa panguva imwe chete, zvichienderana neakasiyana magadzirirwo emagetsi morphology anogona kugadzirwa.
Inopa nzira inoshanda kune ese marudzi eamorphous kabhoni uye greenhouse magasi kuti ashandurwe kuita akakosha nano-yakarongeka graphite zvinhu uye ine yakanaka application tarisiro.
Parizvino, tekinoroji iyi ichiri kutanga. Kune zvishoma zvidzidzo zve graphitization ne electrochemical nzira, uye kuchine akawanda asingazivikanwe maitiro. Naizvozvo, zvinodikanwa kuti utange kubva kune zvigadzirwa uye kuita chidzidzo chakazara uye chakarongeka pane akasiyana amorphous kabhoni, uye panguva imwechete kuongorora iyo thermodynamics uye dynamics yegraphite kutendeuka mune yakadzika nhanho.
Izvi zvine kukosha kukuru kune ramangwana rekusimudzira indasitiri yegraphite.
Nguva yekutumira: May-10-2021