I-Graphite yahlulwe yaba yi-graphite yokwenziwa kunye ne-graphite yendalo, iindawo ezigciniweyo zehlabathi ze-graphite yendalo ezimalunga neetoni ezi-2 zeebhiliyoni.
I-graphite yokwenziwa ifunyanwa ngokubola nonyango lobushushu bezinto ezine-carbon phantsi koxinzelelo oluqhelekileyo. Olu tshintsho lufuna ubushushu obuphezulu namandla aneleyo njengamandla okuqhuba, kwaye isakhiwo esiphazamisekileyo siya kuguqulwa sibe sisakhiwo sekristale se-graphite esicwangcisiweyo.
I-Graphitization ngokwengqiqo ebanzi yezinto ze-carbonaceous ngokusebenzisa unyango lobushushu obuphezulu obungaphezulu kwe-2000 ℃, nangona kunjalo, ezinye izinto ze-carbon kwiqondo lobushushu eliphezulu elingaphezulu kwe-3000 ℃ i-graphitization, olu hlobo lwezinto ze-carbon lwalubizwa ngokuba yi-"hard charcoal", ukuze kube lula ukusebenzisa izinto ze-carbon, indlela yendabuko ye-graphitization ibandakanya indlela yobushushu obuphezulu kunye noxinzelelo oluphezulu, i-catalytic graphitization, indlela yokufaka umphunga wekhemikhali, njl.
Ukwenziwa kwegrafiti yindlela esebenzayo yokusetyenziswa kwexabiso eliphezulu kwezinto ezinekhabhoni. Emva kophando olunzulu nolunzulu olwenziwe zizazi, ngoku sele ivuthiwe. Nangona kunjalo, ezinye izinto ezingathandekiyo ziyawuthintela ukusetyenziswa kwegrafiti yendabuko kushishino, ngoko ke ngumkhwa ongenakuphepheka ukuhlola iindlela ezintsha zokwenziwa kwegrafiti.
Indlela ye-electrolysis yetyuwa enyibilikisiweyo ukususela kwinkulungwane ye-19 ibingaphezulu kwenkulungwane yophuhliso, ithiyori yayo esisiseko kunye neendlela ezintsha zihlala ziyintsha kwaye iphuhlisa, ngoku ayisekho kuphela kushishino lwemveli lwe-metallurgical, ekuqaleni kwenkulungwane yama-21, isinyithi kwinkqubo yetyuwa enyibilikisiweyo ukulungiswa kokunciphisa i-oxide eqinileyo ye-electrolytic yesinyithi esisisiseko sibe yinto ephambili ekusebenzeni ngakumbi,
Kutshanje, indlela entsha yokulungiselela izinto zegrafiti nge-electrolysis yetyuwa enyibilikisiweyo itsale ingqalelo enkulu.
Ngokusebenzisa i-cathodic polarization kunye ne-electrodeposition, iintlobo ezimbini ezahlukeneyo zezinto ezikrwada zekhabhoni ziguqulwa zibe zizinto ze-nano-graphite ezinexabiso elongezelelekileyo. Xa kuthelekiswa netekhnoloji ye-graphitization yendabuko, indlela entsha ye-graphitization ineengenelo zobushushu obuphantsi be-graphitization kunye ne-morphology elawulekayo.
Eli phepha liphonononga inkqubela phambili ye-graphitization ngendlela ye-electrochemical, lazisa obu buchwepheshe butsha, lihlalutya iingenelo kunye neengxaki zalo, kwaye lijonge phambili kwindlela yalo yophuhliso kwixesha elizayo.
Okokuqala, indlela yokupholanisa i-electrolytic cathode yetyuwa enyibilikisiweyo
1.1 izinto ezikrwada
Okwangoku, izinto eziphambili zokwenza i-graphite yokwenziwa yi-needle coke kunye ne-pitch coke enezinga eliphezulu le-graphitization, oko kukuthi, ngokusebenzisa i-oyile residue kunye ne-coal tar njengezinto zokwenza izinto zekhabhoni ezikumgangatho ophezulu, ezine-porosity ephantsi, i-sulfur ephantsi, umxholo ophantsi womlotha kunye neenzuzo ze-graphitization, emva kokulungiswa kwayo ibe yi-graphite inokumelana okuhle nempembelelo, amandla aphezulu oomatshini, ukumelana okuphantsi,
Nangona kunjalo, ukugcinwa kweoyile okuncinci kunye namaxabiso eoyile atshintshatshintshayo kuye kwathintela uphuhliso lwayo, ngoko ke ukufuna izinto ezintsha ezikrwada kuye kwaba yingxaki engxamisekileyo ekufuneka isonjululwe.
Iindlela zemveli zokufaka igrafiti zinemida, kwaye iindlela ezahlukeneyo zokufaka igrafiti zisebenzisa izinto ezahlukeneyo ezikrwada. Kwikhabhoni engeyiyo igrafiti, iindlela zemveli azinakukwazi ukuyifaka igrafiti, ngelixa ifomula ye-electrochemical yetyuwa enyibilikisiweyo iphula umda wezinto ezikrwada, kwaye ifanelekile phantse kuzo zonke izinto zemveli zekhabhoni.
Izinto zekhabhoni zemveli ziquka umnyama wekhabhoni, i-activated carbon, amalahle, njl.njl., apho amalahle elona lithembisayo. I-inki esekwe kumalahle ithatha amalahle njengesandulela kwaye ilungiswa ibe ziimveliso zegrafiti kubushushu obuphezulu emva konyango lwangaphambi konyango.
Kutshanje, eli phepha licebisa iindlela ezintsha ze-electrochemical, ezifana nePeng, nge-electrolysis yetyuwa enyibilikisiweyo akunakwenzeka ukuba i-graphitized carbon black ibe yikristale ephezulu ye-graphite, i-electrolysis yeesampuli ze-graphite eziqulethe iitships ze-graphite nanometer ze-petal shape, inomphezulu othile ophezulu, xa isetyenziselwa i-cathode yebhetri ye-lithium ibonise ukusebenza kakuhle kwe-electrochemical ngaphezu kwe-graphite yendalo.
UZhu nabanye bafaka amalahle acociweyo akumgangatho ophantsi acociweyo kwinkqubo yetyuwa enyibilikisiweyo yeCaCl2 ukuze i-electrolysis ibe yi-950 ℃, baza batshintsha ngempumelelo amalahle akumgangatho ophantsi aba yi-graphite enekristali ephezulu, nto leyo ebonisa ukusebenza kakuhle kunye nobomi bomjikelo omde xa isetyenziswa njenge-anode yebhetri ye-lithium ion.
Olu vavanyo lubonisa ukuba kunokwenzeka ukuguqula iintlobo ezahlukeneyo zezinto zekhabhoni zemveli zibe yigraphite ngokusebenzisa i-electrolysis yetyuwa enyibilikisiweyo, evula indlela entsha yegraphite yokwenziwa yexesha elizayo.
1.2 indlela yokusebenza
Indlela ye-electrolysis yetyuwa enyibilikisiweyo isebenzisa izinto zekhabhoni njenge-cathode kwaye iyiguqula ibe yi-graphite enekristali ephezulu ngokusebenzisa i-cathodic polarization. Okwangoku, uncwadi olukhoyo lukhankanya ukususwa kweoksijini kunye nokulungiswa kwakhona kweeathom zekhabhoni kumgama omde kwinkqubo yokuguqulwa kwe-cathodic polarization.
Ukubakho kweoksijini kwizinto zekhabhoni kuya kuyithintela i-graphitization ukuya kwinqanaba elithile. Kwinkqubo yesiqhelo ye-graphitization, ioksijini iya kususwa kancinci xa ubushushu buphezulu kune-1600K. Nangona kunjalo, kulula kakhulu ukuyisusa nge-cathodic polarization.
UPeng, njl. kwizilingo okokuqala ngqa wabeka phambili indlela enokunyibilika yetyuwa i-electrolysis cathodic polarization potential, oko kukuthi i-graphitization indawo yokuqala kukuba ibekwe kwi-solid carbon microspheres/electrolyte interface, i-carbon microsphere yokuqala ijikeleze i-basic same diameter graphite shell, kwaye emva koko ii-athomu ze-carbon carbon ezizinzileyo azizange zihlale zizinzile zisasazeka kwi-external graphite flake ezizinzileyo, de zibe yi-graphitized ngokupheleleyo.
Inkqubo ye-graphization ihamba nokususwa kweoksijini, eqinisekiswa nazizilingo.
UJin nabanye bakhe babonakalisa olu luvo ngokusebenzisa iimvavanyo. Emva kokwenziwa kwe-carbonization ye-glucose, kwenziwa i-graphitization (umxholo we-oksijini oyi-17%). Emva kokwenziwa kwe-graphitization, ii-solid carbon spheres zokuqala (Umzobo 1a kunye no-1c) zenze igobolondo elineembobo elenziwe ngama-nanosheets e-graphite (Umzobo 1b kunye no-1d).
Ngokusebenzisa i-electrolysis yeefayibha zekhabhoni (i-16% yeoksijini), iifayibha zekhabhoni zinokuguqulwa zibe ziityhubhu zegrafiti emva kokwenziwa kwegrafiti ngokwendlela yokuguqula eqikelelwayo kwiincwadi.
Kukholelwa ukuba, intshukumo yomgama omde iphantsi kwe-cathodic polarization yee-athomu zekhabhoni, i-graphite ephezulu yekristale ukuya kwi-carbon amorphous rearrang kufuneka iqhubeke, i-graphite yokwenziwa kunye neepetali ezizodwa zinee-nanostructures ezizuze kwii-athomu ze-oksijini, kodwa indlela ethile yokuphembelela isakhiwo se-graphite nanometer ayicacanga, njenge-oksijini evela kwi-carbon skeleton emva kokuba i-cathode reaction iphelile, njl.
Okwangoku, uphando malunga nale ndlela lusekwinqanaba lokuqala, kwaye uphando olongezelelweyo luyadingeka.
1.3 Indlela igraphite eyenziwe ngayo ichazwa ngayo ngokwemo yayo
I-SEM isetyenziselwa ukujonga imo yobuso be-graphite nge-microscopic, i-TEM isetyenziselwa ukujonga imo yolwakhiwo engaphantsi kwe-0.2 μm, i-XRD kunye ne-Raman spectroscopy zezona ndlela zisetyenziswa kakhulu ukuchaza imo yolwakhiwo lwe-graphite, i-XRD isetyenziselwa ukuchaza ulwazi lwekristale lwe-graphite, kwaye i-Raman spectroscopy isetyenziselwa ukuchaza iziphene kunye nomgangatho wolandelelwano lwe-graphite.
Kukho iimbobo ezininzi kwi-graphite ezilungiselelwe yi-cathode polarization ye-electrolysis yetyuwa enyibilikisiweyo. Kwizinto ezahlukeneyo eziluhlaza, ezifana ne-carbon black electrolysis, kufunyanwa ii-nanostructures ezifana ne-petal-porous. Uhlalutyo lwe-XRD kunye ne-Raman spectrum lwenziwa kwi-carbon black emva kwe-electrolysis.
Kwi-827 ℃, emva kokuphathwa nge-voltage ye-2.6V kangangeyure eli-1, umfanekiso we-Raman spectral we-carbon black uphantse ufane nowe-graphite yorhwebo. Emva kokuba i-carbon black iphathwe ngamaqondo obushushu ahlukeneyo, i-graphite characteristic peak ebukhali (002) iyalinganiswa. I-diffraction peak (002) imele inqanaba lokujonga umaleko we-carbon onuka kamnandi kwi-graphite.
Okukhona umaleko wekhabhoni ubukhali, kokukhona ujongeka ngakumbi.
UZhu wasebenzisa ilahle eliphantsi elicociweyo njenge-cathode kuvavanyo, kwaye isakhiwo semveliso ye-graphitized saguqulwa ukusuka kwi-granular ukuya kwisakhiwo esikhulu se-graphite, kwaye umaleko we-graphite oqinileyo nawo wabonwa phantsi kwe-high rate transmission electron microscope.
Kwi-Raman spectra, ngotshintsho lweemeko zovavanyo, ixabiso le-ID/Ig nalo latshintsha. Xa ubushushu be-electrolytic babuyi-950 ℃, ixesha le-electrolytic laliyi-6h, kwaye i-voltage ye-electrolytic yayiyi-2.6V, ixabiso eliphantsi le-ID/Ig laliyi-0.3, kwaye i-D peak yayiphantsi kakhulu kune-G peak. Kwangaxeshanye, ukubonakala kwe-2D peak nako kwakubonisa ukwakheka kwesakhiwo se-graphite esicwangcisiweyo kakhulu.
Incopho ebukhali (002) yokusasazwa kombane kumfanekiso we-XRD ikwaqinisekisa ukuguqulwa ngempumelelo kwamalahle angaphantsi abe yi-graphite enekristali ephezulu.
Kwinkqubo yokwenza i-graphitization, ukunyuka kobushushu kunye ne-voltage kuya kudlala indima yokunyusa, kodwa i-voltage ephezulu kakhulu iya kunciphisa isivuno se-graphite, kwaye ubushushu obuphezulu kakhulu okanye ixesha elide kakhulu lokwenza i-graphitization liya kukhokelela ekuchithekeni kwezixhobo, ngoko ke kwizinto ezahlukeneyo zekhabhoni, kubaluleke kakhulu ukuphonononga iimeko ezifanelekileyo ze-electrolytic, kukwayinto ephambili kunye nobunzima.
Le nanostructure efana nepetal flake ineempawu ezintle kakhulu ze-electrochemical. Inani elikhulu lee-pores livumela ii-ion ukuba zifakwe/zisuswe ngokukhawuleza, nto leyo ebonelela ngezinto ze-cathode ezisemgangathweni ophezulu kwiibhetri, njl. Ke ngoko, i-electrochemical method graphitization yindlela enokwenzeka kakhulu ye-graphitization.
Indlela yokuma kwe-electrode yetyuwa enyibilikisiweyo
2.1 Ukufakwa kwe-electrode kwi-carbon dioxide
Njengeyona gesi ibalulekileyo yegreenhouse, i-CO2 ikwangumthombo ohlaziyekayo ongenabungozi, ongenabungozi, ongabizi kakhulu kwaye ofumaneka lula. Nangona kunjalo, ikhabhoni kwi-CO2 ikwimeko ephezulu ye-oxidation, ngoko ke i-CO2 inozinzo oluphezulu lwe-thermodynamic, nto leyo eyenza kube nzima ukuyisebenzisa kwakhona.
Uphando lokuqala malunga nokuma kwe-CO2 electrode lungalandelelwa emva kwiminyaka yoo-1960. U-Ingram nabanye balungiselela ngempumelelo i-carbon kwi-electrode yegolide kwinkqubo yetyuwa enyibilikisiweyo ye-Li2CO3-Na2CO3-K2CO3.
UVan et al. babonise ukuba iipowder zekhabhoni ezifunyenwe kwiindlela ezahlukeneyo zokunciphisa zinezakhiwo ezahlukeneyo, kuquka i-graphite, i-carbon engabonakaliyo kunye ne-carbon nanofibers.
Ngokusebenzisa ityuwa enyibilikisiweyo ukuze kubanjwe i-CO2 kunye nendlela yokulungiselela impumelelo yezinto zekhabhoni, emva kwexesha elide leengcali zophando zigxile kwindlela yokwakheka kwekhabhoni kunye nempembelelo yeemeko ze-electrolysis kwimveliso yokugqibela, equka ubushushu be-electrolytic, i-voltage ye-electrolytic kunye nokwakheka kwetyuwa enyibilikisiweyo kunye nee-electrodes, njl.njl., ukulungiswa kokusebenza okuphezulu kwezinto zegrafiti zokubeka i-electrode ye-CO2 kubeke isiseko esiqinileyo.
Ngokutshintsha i-electrolyte nokusebenzisa inkqubo yetyuwa enyibilikisiweyo esekwe kwi-CaCl2 enobuchule obuphezulu bokubanjwa kwe-CO2, uHu nabanye balungiselele ngempumelelo i-graphene enezinga eliphezulu le-graphitization kunye nee-carbon nanotubes kunye nezinye izakhiwo ze-nanographite ngokufunda iimeko ze-electrolytic ezifana nobushushu be-electrolysis, ukwakheka kwe-electrode kunye nokwakheka kwetyuwa enyibilikisiweyo.
Xa ithelekiswa nenkqubo ye-carbonate, i-CaCl2 ineenzuzo zokuba ingabizi kwaye kulula ukuyifumana, i-conductivity ephezulu, kulula ukuyinyibilikisa emanzini, kunye nokunyibilika okuphezulu kwee-ion ze-oxygen, ezibonelela ngeemeko zethiyori zokuguqulwa kwe-CO2 ibe yimveliso yegrafiti enexabiso elongezelelweyo.
2.2 Indlela yoGuquko
Ukulungiswa kwezinto zekhabhoni ezinexabiso eliphezulu ngokubeka i-CO2 kwityuwa enyibilikisiweyo kubandakanya ukubanjwa kwe-CO2 kunye nokunciphisa ngokungathanga ngqo. Ukubanjwa kwe-CO2 kugqitywa yityuwa enyibilikisiweyo ye-O2- ekhululekileyo, njengoko kubonisiwe kwiSilinganiso (1):
CO2+O2-→CO3 2- (1)
Okwangoku, kuye kwacetyiswa iindlela ezintathu zokunciphisa ngokungangqalanga: ukusabela okunenyathelo elinye, ukusabela okunenyathelo ezimbini kunye nendlela yokunciphisa isinyithi.
Indlela yokusabela yenyathelo elinye yaqala ukucetyiswa ngu-Ingram, njengoko kubonisiwe kwi-Equation (2):
CO3 2-+ 4E – →C+3O2- (2)
Indlela yokusabela enamanyathelo amabini yacetywa nguBorucka et al., njengoko kubonisiwe kwi-Equation (3-4):
CO3 2-+ 2E – →CO2 2-+O2- (3)
I-CO2 2-+ 2E – →C+2O2- (4)
Indlela yokusabela kokunciphisa isinyithi yacetywa nguDeanhardt et al. Babekholelwa ukuba ii-ion zesinyithi zaqala zancitshiswa zaba yintsimbi kwi-cathode, zaza emva koko isinyithi sancitshiswa saba yi-ion ze-carbonate, njengoko kubonisiwe kwi-Equation (5~6):
M- + E – →M (5)
4 m + M2CO3 – > C + 3 m2o (6)
Okwangoku, indlela yokusabela yenyathelo elinye iyamkelwa ngokubanzi kwiincwadi ezikhoyo.
UYin nabanye bafunde inkqubo ye-Li-Na-K carbonate ene-nickel njenge-cathode, i-tin dioxide njenge-anode kunye ne-silver wire njenge-electrode yokubhekisa, baza bafumana umfanekiso wovavanyo lwe-cyclic voltammetry kuMfanekiso 2 (izinga lokuskena le-100 mV/s) kwi-nickel cathode, baza bafumanisa ukuba kukho incopho enye yokunciphisa (kwi--2.0V) kwi-negative scanning.
Ngoko ke, kunokugqitywa kwelokuba kukho impendulo enye kuphela eyenzekileyo ngexesha lokunciphisa i-carbonate.
UGao nabanye bafumana i-cyclic voltammetry efanayo kwinkqubo efanayo ye-carbonate.
UGe nabanye basebenzise i-anode engangeniyo kunye ne-tungsten cathode ukubamba i-CO2 kwinkqubo ye-LiCl-Li2CO3 baza bafumana imifanekiso efanayo, kwaye kuphela incopho yokunciphisa ukubekwa kwekhabhoni ebonakele kwi-negative scanning.
Kwinkqubo yetyuwa enyibilikisiweyo yesinyithi se-alkaline, iimetali ze-alkali kunye ne-CO ziya kuveliswa ngelixa ikhabhoni ibekwa yi-cathode. Nangona kunjalo, ngenxa yokuba iimeko ze-thermodynamic zempendulo yekhabhoni ziphantsi kubushushu obuphantsi, kuphela ukwehla kwekhabhoni ibe yikhabhoni okunokubonwa kuvavanyo.
2.3 Ukubanjwa kwe-CO2 ngetyuwa enyibilikisiweyo ukulungiselela iimveliso zegrafiti
Izinto ze-graphite nanomaterials ezinexabiso eliphezulu ezifana ne-graphene kunye nee-carbon nanotubes zinokulungiswa ngokubeka i-CO2 kwi-electrode kwityuwa enyibilikisiweyo ngokulawula iimeko zovavanyo. UHu et al. basebenzise intsimbi engagqwaliyo njenge-cathode kwinkqubo yetyuwa enyibilikisiweyo ye-CaCl2-NaCl-CaO kwaye bayifaka i-electrolyze kangangeeyure ezi-4 phantsi kwemeko ye-voltage engaguqukiyo ye-2.6V kumaqondo obushushu ahlukeneyo.
Ngenxa ye-catalysis yesinyithi kunye nefuthe eliqhumayo le-CO phakathi kweengqimba zegrafiti, i-graphene yafunyanwa kumphezulu we-cathode. Inkqubo yokulungiselela i-graphene iboniswe kuMfanekiso 3.
Umfanekiso
Izifundo kamva zongeze iLi2SO4 ngokusekelwe kwinkqubo yetyuwa enyibilikisiweyo yeCaCl2-NaClCaO, ubushushu be-electrolysis babuyi-625 ℃, emva kweeyure ezi-4 ze-electrolysis, kwangaxeshanye kwi-cathodic deposition ye-carbon efunyenwe i-graphene kunye ne-carbon nanotubes, uphando lufumanise ukuba iLi+ kunye neSO4 2- zizisa impembelelo entle kwi-graphitization.
I-sulfur ikwadibaniswa ngempumelelo nomzimba wekhabhoni, kwaye amaphepha e-graphite abhityile kakhulu kunye nekhabhoni ene-filamentous anokufunyanwa ngokulawula iimeko ze-electrolytic.
Izinto ezifana nobushushu obuphezulu nobuphantsi be-electrolytic bokwakhiwa kwe-graphene zibalulekile, xa ubushushu obuphezulu kuno-800 ℃ kulula ukuvelisa i-CO endaweni ye-carbon, phantse akukho carbon deposition xa ingaphezulu kuno-950 ℃, ngoko ke ulawulo lobushushu lubaluleke kakhulu ukuvelisa i-graphene kunye neetyhubhu ze-carbon nanotubes, kwaye ukubuyisela isidingo sokudibanisa i-carbon deposition reaction CO ukuze kuqinisekiswe ukuba i-cathode ivelisa i-graphene ezinzileyo.
Le misebenzi ibonelela ngendlela entsha yokulungiselela iimveliso ze-nano-graphite nge-CO2, ebaluleke kakhulu kwisisombululo seegesi ezibangela ubushushu kunye nokulungiselela i-graphene.
3. Isishwankathelo kunye neMbono
Ngenxa yophuhliso olukhawulezileyo lweshishini elitsha lamandla, i-graphite yendalo ayikwazanga ukuhlangabezana neemfuno zangoku, kwaye i-graphite yokwenziwa ineempawu zomzimba nezekhemikhali ezingcono kune-graphite yendalo, ngoko ke i-graphitization engabizi, esebenzayo neyobuhlobo nokusingqongileyo yinjongo yexesha elide.
Iindlela ze-electrochemical graphitization kwizixhobo eziqinileyo nezinegesi ngendlela ye-cathodic polarization kunye ne-electrochemical deposition ziphume ngempumelelo kwizixhobo ze-graphite ezinexabiso eliphezulu elongeziweyo, xa kuthelekiswa nendlela yendabuko ye-graphitization, indlela ye-electrochemical isebenza kakuhle kakhulu, ukusetyenziswa kwamandla aphantsi, ukhuseleko oluluhlaza kokusingqongileyo, kuba izinto ezincinci zinqunyelwe zizinto ezikhethiweyo ngaxeshanye, ngokweemeko ezahlukeneyo ze-electrolysis zinokulungiswa kwi-morphology eyahlukeneyo yesakhiwo se-graphite,
Ibonelela ngendlela esebenzayo yokuba zonke iintlobo ze-carbon amorphous kunye neegesi ze-greenhouse ziguqulwe zibe zizinto ezixabisekileyo ze-graphite ezakhiwe ngendlela encinci kwaye zinethuba elihle lokusetyenziswa.
Okwangoku, obu buchwephesha busesebuncinaneni. Zimbalwa izifundo malunga nokuguqulwa kwegrafu ngendlela ye-electrochemical, kwaye kusekho iinkqubo ezininzi ezingaziwayo. Ke ngoko, kuyimfuneko ukuqala kwizinto eziluhlaza kwaye wenze uphando olupheleleyo nolucwangcisiweyo kwiikhabhoni ezahlukeneyo ze-amorphous, kwaye kwangaxeshanye uhlolisise i-thermodynamics kunye ne-dynamics yokuguqulwa kwegrafu kwinqanaba elinzulu.
Ezi zinto zibaluleke kakhulu kuphuhliso lwexesha elizayo lweshishini legrafiti.
Ixesha lokuthumela: Meyi-10-2021