A na-ekewa graphite ka ọ bụrụ graphite wuruwuru na graphite eke, ihe nchekwa graphite eke egosipụtara n'ụwa n'ihe dị ka ijeri ijeri abụọ.
A na-enweta graphite artificial site na nbibi na ọgwụgwọ okpomọkụ nke ihe ndị nwere carbon n'okpuru nrụgide nkịtị. Ngbanwe a na-achọ oke okpomọkụ na ume dị elu dị ka ike na-anya ụgbọ ala, a ga-agbanwe usoro ahụ mebiri emebi ka ọ bụrụ nhazi kristal graphite nyere iwu.
Graphitization bụ n'echiche sara mbara nke carbonaceous ihe site na n'elu 2000 ℃ okpomọkụ okpomọkụ ọgwụgwọ carbon atom rearrangement, Otú ọ dị ụfọdụ carbon ihe na elu okpomọkụ n'elu 3000 ℃ graphitization, ụdị carbon ihe a maara dị ka "ike unyi", maka mfe graphitized carbon, usoro nke usoro okpomọkụ dị elu na-agụnye usoro okpomọkụ dị elu, usoro ihe osise dị elu na usoro okpomọkụ, usoro mmepụta ihe na-eme ka usoro okpomọkụ dị elu. usoro ntinye uzuoku, wdg.
Graphitization bụ ụzọ dị irè nke itinye uru dị elu nke ihe carbonaceous. Ka ndị ọkà mmụta nyochachara nke ọma na nke miri emi, o tozuru oke ugbu a. Otú ọ dị, ụfọdụ ihe na-adịghị mma na-egbochi ngwa nke graphitization omenala na ụlọ ọrụ, n'ihi ya, ọ bụ ihe a na-apụghị izere ezere iji nyochaa ụzọ graphitization ọhụrụ.
Elekere nnu electrolysis usoro kemgbe narị afọ nke 19 bụ ihe karịrị otu narị afọ nke mmepe, ya bụ isi tiori na ọhụrụ ụzọ na-mgbe niile ọhụrụ na mmepe, ugbu a agaghịkwa ejedebere na omenala metallurgical ụlọ ọrụ, ná mmalite nke narị afọ nke 21, na metal ke gbazere nnu usoro siri ike oxide electrolytic Mbelata nkwadebe nke elemental ọla aghọwo ndị na-elekwasị anya na ndị ọzọ na-arụsi ọrụ ike,
N'oge na-adịbeghị anya, usoro ọhụrụ maka ịkwadebe ihe graphite site na electrolysis nnu a wụrụ awụ adọtala mmasị dị ukwuu.
Site na polarization cathodic na electrodeposition, ụdị abụọ dị iche iche nke akụrụngwa carbon na-agbanwe ka ọ bụrụ ihe nano-graphite nwere uru dị elu. E jiri ya tụnyere nkà na ụzụ graphitization ọdịnala, usoro graphitization ọhụrụ ahụ nwere uru nke okpomọkụ graphitization dị ala na morphology na-achịkwa.
Akwụkwọ a na-enyocha ọganihu nke graphitization site na usoro electrochemical, na-ewebata nkà na ụzụ ọhụrụ a, nyochaa uru na ọghọm ya, ma na-atụ anya usoro mmepe ya n'ọdịnihu.
Nke mbụ, a gbazere nnu electrolytic cathode polarization usoro
1.1 ihe eji eme ihe
Ugbu a, isi akụrụngwa nke artificial graphite bụ agịga coke na pitch coke nke elu graphitization ogo, ya bụ site mmanụ fọdụrụnụ na coal tar dị ka akụrụngwa na-emepụta a elu-edu carbon ihe, na ala porosity, ala sọlfọ, ala uyi ọdịnaya na uru nke graphitization, mgbe nkwadebe ya n'ime graphite nwere ezigbo iguzogide mmetụta, elu n'ibu ike, ala resistivity, ala resistivity.
Agbanyeghị, oke nchekwa mmanụ na ọnụ ahịa mmanụ na-agbanwe agbanwe egbochila mmepe ya, yabụ ịchọ akụrụngwa ọhụrụ abụrụla nsogbu dị ngwa a ga-edozi.
Ụzọ graphitization omenala nwere oke, na ụzọ graphitization dị iche iche na-eji ngwa dị iche iche. Maka carbon na-abụghị graphitized, usoro ọdịnala enweghị ike ịkọwa ya, ebe usoro elektrọnịkị nke nnu a wụrụ awụ na-agbaji site na mmachi nke akụrụngwa, yana dabara maka ihe niile carbon ọdịnala.
Ihe carbon carbon ọdịnala gụnyere carbon ojii, carbon arụ ọrụ, coal, wdg, n'ime nke coal bụ nke kacha ekwe nkwa. Ink dabeere na coal na-ewere coal dị ka ihe mbụ ma kwadebere ya na ngwaahịa graphite na okpomọkụ dị elu mgbe a gwọchara ya.
Na nso nso a, akwụkwọ a obụp ọhụrụ electrochemical ụzọ, dị ka Peng, site a wụrụ awụ electrolysis bụ eleghi anya graphitized carbon nwa n'ime elu crystallinity nke graphite, na electrolysis nke graphite samples nwere petal udi graphite nanometer ibe, nwere elu kpọmkwem elu ebe, mgbe eji lithium batrị cathode gosiri magburu onwe electrochemical arụmọrụ karịa eke graphite arụmọrụ.
Zhu et al. tinye deashing mesoro coal dị ala n'ime usoro nnu a wụrụ awụ nke CaCl2 maka electrolysis na 950 ℃, wee gbanwee nke ọma coal dị ala ka ọ bụrụ graphite nwere nnukwu crystallinity, nke gosipụtara arụmọrụ ọnụego dị mma na ogologo ndụ okirikiri mgbe ejiri ya dị ka anode nke batrị lithium ion.
Nnwale ahụ na-egosi na ọ ga-ekwe omume ịtụgharị ụdị carbon carbon dị iche iche ka ọ bụrụ graphite site na nnu a wụrụ awụ, bụ nke na-emepe ụzọ ọhụrụ maka graphite sịntetik n'ọdịnihu.
1.2 usoro nke
Usoro nnu a wụrụ awụ na-eji ihe carbon dị ka cathode wee tụgharịa ya ka ọ bụrụ graphite nwere nnukwu crystallinity site na polarization cathodic. Ka ọ dị ugbu a, akwụkwọ ndị dị ugbu a na-ekwu maka iwepụ oxygen na nhazigharị anya nke carbon carbon na usoro ntụgharị nke cathodic polarization nwere ike ime.
Ọnụnọ nke oxygen na ihe carbon ga-egbochi graphitization ruo n'ókè ụfọdụ. N'ime usoro eserese nke ọdịnala, oxygen ga-eji nwayọọ nwayọọ wepụ ya mgbe okpomọkụ dị elu karịa 1600K. Agbanyeghị, ọ dị oke mma iji deoxidize site na polarization cathodic.
Peng, wdg na nnwale maka oge mbụ tinye n'ihu nnu a wụrụ awụ electrolysis cathodic polarization usoro nwere ike, ya bụ graphitization kasị ebe na-amalite bụ na-emi odude ke siri ike carbon microspheres / electrolyte interface, mbụ carbon microsphere na-etolite gburugburu a isi otu dayameta graphite shei, na mgbe ahụ, ọ dịghị mgbe kwụsiri ike anhydrous carbon carbon carbon atoms gbasaa ka kwụsie ike n'èzí, ruo mgbe graphite flagraphite na-agbasa ka kwụsie ike n'èzí, ruo mgbe graphite flagraph.
Usoro graphitization na-esonyere na mwepụ nke oxygen, nke a na-akwadokwa site na nyocha.
Jin et al. gosikwara echiche a site na nnwale. Mgbe carbonization nke glucose gasịrị, a na-eme grafitization (17% oxygen ọdịnaya). Mgbe graphitization, mbụ siri ike carbon spheres (Fig. 1a na 1c) kpụrụ a porous shei mejupụtara graphite nanosheets (Fig. 1b na 1d).
Site na electrolysis nke carbon fibers (16% oxygen), enwere ike ịtụgharị carbon fibers ka ọ bụrụ tubes graphite mgbe graphitization dị ka usoro ngbanwe nke akọwara n'akwụkwọ.
Kwere na, ogologo anya ije bụ n'okpuru cathodic polarization nke carbon atọm na elu crystal graphite ka amorphous carbon rearrange ga hazie, sịntetik graphite pụrụ iche petals na-akpụ nanostructures uru site oxygen atọm si, ma kpọmkwem otú mmetụta graphite nanometer Ọdịdị bụ doro anya, dị ka oxygen si carbon skeletonde mgbe otú na cathoton.
Ka ọ dị ugbu a, nyocha nke usoro ahụ ka nọ na mmalite mmalite, a chọkwara nyocha ọzọ.
1.3 Nkọwapụta gbasara mmụọ nke graphite sịntetik
A na-eji SEM na-ekiri ihe omimi nke graphite nke microscopic, a na-eji TEM na-ahụ usoro nhazi nke ihe na-erughị 0.2 μm, XRD na Raman spectroscopy bụ ihe a na-ejikarị eme ihe iji mara microstructure nke graphite, XRD na-eji mara ozi kristal nke graphite, na Raman orders grafite na-eji akara ngosi.
Enwere ọtụtụ pores na graphite nke a kwadebere site na cathode polarization nke nnu a wụrụ awụ electrolysis. Maka akụrụngwa dị iche iche, dị ka carbon black electrolysis, petal-dị ka porous nanostructures na-enwetara. A na-eme nyocha ụdị dị iche iche nke XRD na Raman na carbon ojii mgbe electrolysis gasịrị.
Na 827 ℃, mgbe ejiri 2.6V voltaji agwọ ya maka 1h, ihe onyonyo nke Raman nke carbon ojii fọrọ nke nta ka ọ bụrụ otu nke graphite azụmahịa. Mgbe ejiri okpomoku dị iche iche meso oji carbon ahụ, a na-atụ ọnụ ọgụgụ kacha elu nke graphite (002). Ọnụ ọgụgụ kachasị elu (002) na-anọchi anya ogo nghazi nke oyi akwa carbon aromatic na graphite.
Ka carbon oyi akwa na-adị nkọ karị, ka ọ na-agbado anya karị.
Zhu jiri kol dị obere dị ọcha dị ka cathode na nnwale ahụ, a gbanwere microstructure nke ngwaahịa graphitized site na granular gaa na nnukwu eserese graphite, a na-ahụkwa oyi akwa graphite siri ike n'okpuru microscope eletrọn dị elu.
Na Raman spectra, na mgbanwe nke ọnọdụ nnwale, uru ID/Ig agbanwekwara. Mgbe electrolytic okpomọkụ bụ 950 ℃, electrolytic oge bụ 6h, na electrolytic voltaji bụ 2.6V, kasị ala ID / Ig uru bụ 0.3, na ọnụ ọnụ D dị nnọọ ala karịa G elu. N'otu oge ahụ, mpụta nke 2D ọnụ ọgụgụ kasị elu na-anọchi anya nguzobe nke usoro graphite nke ukwuu nyere iwu.
Ọnụ ọgụgụ kasị elu dị nkọ (002) dị na foto XRD na-egosikwa ngbanwe nke ọma nke coal dị ala n'ime graphite nwere nnukwu crystallinity.
Na usoro graphitization, mmụba nke okpomọkụ na voltaji ga-arụ ọrụ na-akwalite, ma oke voltaji ga-ebelata mkpụrụ nke graphite, na oke okpomọkụ ma ọ bụ ogologo oge graphitization ga-eduga n'iyi nke ihe onwunwe, ya mere maka ihe dị iche iche carbon, ọ dị mkpa karịsịa iji nyochaa ọnọdụ electrolytic kasị mma, bụkwa ihe na-elekwasị anya na ihe isi ike.
Nke a petal-dị ka flake nanostructure nwere magburu onwe electrochemical Njirimara. Ọnụ ọgụgụ dị ukwuu nke pores na-ekwe ka ion ngwa ngwa tinye / deembedded, na-enye ihe dị elu cathode maka batrị, wdg. Ya mere, usoro electrochemical graphitization bụ nnọọ ike graphitization usoro.
Usoro electrodeposition nnu gbazere
2.1 Electrodeposition nke carbon dioxide
Dị ka gas griin haus kacha mkpa, CO2 bụkwa ihe na-adịghị egbu egbu, nke na-adịghị emerụ ahụ, dị ọnụ ala ma dị mfe ịnweta. Otú ọ dị, carbon na CO2 nọ na steeti oxidation kasị elu, ya mere CO2 nwere nkwụsi ike nke thermodynamic dị elu, nke na-eme ka o sie ike iji mee ihe ọzọ.
Enwere ike ịchọta nchọpụta mbụ na CO2 electrodeposition na 1960s. Ingram et al. kwadebere nke ọma carbon na electrode ọla edo na sistemụ nnu gbazere nke Li2CO3-Na2CO3-K2CO3.
Van et al. rụtụrụ aka na ntụ ntụ carbon enwetara na ikike mbelata dị iche iche nwere usoro dị iche iche, gụnyere graphite, carbon amorphous na carbon nanofibers.
Site gbazere nnu weghara CO2 na nkwadebe usoro nke carbon ihe ịga nke ọma, mgbe ogologo oge nke nnyocha ndị ọkà mmụta lekwasịrị anya carbon deposition guzobe usoro na mmetụta nke electrolysis ọnọdụ na ikpeazụ ngwaahịa, nke gụnyere electrolytic okpomọkụ, electrolytic voltaji na mejupụtara nke wụrụ awụ nnu na electrodes, wdg, nkwadebe nke elu arụmọrụ nke graphite ihe maka electrodeposition nke CO2 tọrọ ntọala siri ike.
Site n'ịgbanwe electrolyte na iji usoro nnu a wụrụ awụ nke CaCl2 nwere arụmọrụ CO2 dị elu, Hu et al. kwadebere nke ọma graphene nwere ogo graphitization dị elu na carbon nanotubes na ihe ndị ọzọ nanographite site n'ịmụ ọnọdụ electrolytic dị ka okpomọkụ electrolysis, ihe mejupụtara electrode na ngwakọta nnu gbazere.
E jiri ya tụnyere usoro carbonate, CaCl2 nwere uru dị ọnụ ala ma dị mfe ịnweta, elu conductivity, dị mfe igbari na mmiri, na elu solubility nke oxygen ion, nke na-enye usoro usoro maka ntughari nke CO2 n'ime graphite ngwaahịa na elu gbakwunyere uru.
2.2 Usoro mgbanwe
Nkwadebe nke ihe carbon bara uru dị elu site na electrodeposition nke CO2 sitere na nnu a wụrụ awụ na-agụnye njide CO2 na mbelata ozugbo. Emechara ijide CO2 site na O2- na nnu a wụrụ awụ n'efu, dị ka egosiri na nha (1):
CO2+O2-→CO3 2- (1)
Ka ọ dị ugbu a, a tụpụtala usoro mmeghachi omume mbelata atọ na-apụtachaghị ìhè: mmeghachi omume otu nzọụkwụ, mmeghachi omume nzọụkwụ abụọ na usoro mmeghachi omume mbelata ígwè.
Ingram tụpụtara usoro mmeghachi omume otu nzọụkwụ mbụ, dịka egosiri na nha (2):
CO3 2-+ 4E – →C+3O2- (2)
Borucka et al tụpụtara usoro mmeghachi omume nzọụkwụ abụọ, dịka egosiri na nha nha (3-4):
CO3 2-+ 2E – →CO2 2-+O2- (3)
CO2 2-+ 2E – →C+2O2- (4)
Usoro mmeghachi omume mbelata metal bụ nke Deanhardt et al tụpụtara ya. Ha kwenyere na ion metal na-ebu ụzọ belata ka ọ bụrụ metal na cathode, wee belata metal ahụ ka ọ bụrụ ion carbonate, dị ka egosiri na nha (5 ~ 6):
M- + E – →M (5)
4 m + M2CO3 – > C + 3 m2o (6)
Ka ọ dị ugbu a, a na-anabata usoro mmeghachi omume nke otu nzọụkwụ n'akwụkwọ ndị dị ugbu a.
Yin et al. mụọ usoro Li-Na-K carbonate na nickel dị ka cathode, tin dioxide dị ka anode na ọlaọcha ọlaọcha dị ka electrode ntụaka, wee nweta ọnụọgụ nyocha nke cyclic voltammetry na Figure 2 (ọnụego nyocha nke 100 mV / s) na nickel cathode, wee chọpụta na ọ bụ naanị otu mbelata elu (na -2.0V) na nyocha na-adịghị mma.
Ya mere, enwere ike ikwubi na ọ bụ naanị otu mmeghachi omume mere n'oge mbelata carbonate.
Gao et al. nwetara otu voltammetry cyclic n'otu sistemu carbonate.
Ge et al. eji inert anode na tungsten cathode weghara CO2 na sistemu LiCl-Li2CO3 wee nweta ihe onyonyo yiri ya, na naanị mbelata elu nke ntinye carbon pụtara na nyocha na-adịghị mma.
N'ime usoro nnu a wụrụ awụ nke alkaline, a ga-emepụta ọla alkali na CO ka cathode na-echekwa carbon. Otú ọ dị, n'ihi na ọnọdụ thermodynamic nke mmeghachi omume ntinye carbon dị ala na obere okpomọkụ, naanị mbelata carbonate na carbon ka enwere ike ịhụ na nnwale ahụ.
2.3 CO2 ijide nnu gbazere iji kwadebe ngwaahịa graphite
Enwere ike ịkwadebe nanomaterials graphite dị elu dị elu dị ka graphene na carbon nanotubes site na electrodeposition nke CO2 sitere na nnu gbazere site na ịchịkwa ọnọdụ nnwale. Hu et al. eji igwe anaghị agba nchara dị ka cathode na usoro nnu a wụrụ awụ nke CaCl2-NaCl-CaO na electrolyzed maka 4h n'okpuru ọnọdụ nke voltaji 2.6V mgbe niile na okpomọkụ dị iche iche.
N'ihi catalysis nke ígwè na mmetụta mgbawa nke CO n'etiti graphite layers, a chọtara graphene n'elu cathode. E gosipụtara usoro nkwadebe nke graphene na Fig 3.
Foto a
Mgbe e mesịrị ọmụmụ kwukwara Li2SO4 na ndabere nke CaCl2-NaClCaO a wụrụ awụ usoro nnu, electrolysis okpomọkụ bụ 625 ℃, mgbe 4h nke electrolysis, n'otu oge ahụ na cathodic ntinye nke carbon hụrụ graphene na carbon nanotubes, ọmụmụ chọpụtara na Li + na SO4 2- na-eweta mmetụta dị mma na graphitization.
A na-ejikọta sọlfọ nke ọma n'ime ahụ carbon, na enwere ike nweta mpempe akwụkwọ graphite dị oke mkpa na carbon filamentous site na ịchịkwa ọnọdụ electrolytic.
Ihe dị ka electrolytic okpomọkụ nke elu na ala maka e guzobere graphene dị oké egwu, mgbe okpomọkụ dị elu karịa 800 ℃ dị mfe n'ịwa CO kama carbon, ọ fọrọ nke nta ka ọ dịghị carbon ntinye mgbe elu karịa 950 ℃, otú okpomọkụ akara dị oké mkpa na-emepụta graphene na carbon nanotubes, na weghachi mkpa carbon deposition mmeghachi omume CO mmeghachi omume synerhode iji hụ na n'ịwa ahụ siri ike.
Ọrụ ndị a na-enye usoro ọhụrụ maka nkwadebe ngwaahịa nano-graphite site na CO2, nke dị oke mkpa maka ngwọta nke gas griin haus na nkwadebe nke graphene.
3. Nchịkọta na Outlook
Site na mmepe ngwa ngwa nke ụlọ ọrụ ume ọhụrụ, graphite eke enweghị ike imezu ihe a chọrọ ugbu a, na graphite artificial nwere akụrụngwa anụ ahụ na kemịkalụ ka mma graphite eke, yabụ ọnụ ala, nke ọma na graphitization na gburugburu ebe obibi bụ ebumnuche ogologo oge.
Electrochemical ụzọ graphitization na siri ike na gaseous akụrụngwa na usoro nke cathodic polarization na electrochemical deposition bụ nke ọma si na graphite ihe na elu agbakwunyere uru, ma e jiri ya tụnyere omenala ụzọ graphitization, na electrochemical usoro bụ nke elu arụmọrụ, obere ume oriri, green gburugburu ebe obibi nchebe, maka obere mmachi site nhọrọ ihe n'otu oge, dị ka dị iche iche electrolysis Ọdịdị nwere ike kwadebere n'ụdị dị iche iche electrolysis.
Ọ na-enye ụzọ dị irè maka ụdị carbon amorphous na ikuku griin ha ga-agbanwe ka ọ bụrụ ihe graphite arụnyere nano bara uru ma nwee atụmanya ngwa dị mma.
Ka ọ dị ugbu a, teknụzụ a ka dị ọhụrụ. Enwere ọmụmụ ole na ole gbasara graphitization site na usoro electrochemical, ma a ka nwere ọtụtụ usoro a na-amaghị. Ya mere, ọ dị mkpa ịmalite site na akụrụngwa ma na-eduzi ọmụmụ ihe zuru oke na nhazi usoro dị iche iche nke carbon amorphous, ma n'otu oge ahụ nyochaa thermodynamics na ike nke ntụgharị graphite na ọkwa dị omimi.
Ndị a nwere uru dị ukwuu maka mmepe nke ụlọ ọrụ graphite n'ọdịnihu.
Oge nzipu: Mee-10-2021