A handbook for graphitic carbon nitrides: revisiting the thermal synthesis and characterization towards experimental standardization

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Fidan T., Arat R., Bayazit M. K.

MATERIALS RESEARCH EXPRESS, vol.10, no.9, pp.95905-95918, 2023 (SCI-Expanded)

  • Publication Type: Article / Article
  • Volume: 10 Issue: 9
  • Publication Date: 2023
  • Doi Number: 10.1088/2053-1591/acf9dd
  • Journal Name: MATERIALS RESEARCH EXPRESS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, Compendex, INSPEC, Metadex, Directory of Open Access Journals, Civil Engineering Abstracts
  • Page Numbers: pp.95905-95918
  • Open Archive Collection: AVESIS Open Access Collection
  • Istanbul University Affiliated: Yes

Abstract

Graphiticcarbonnitrides(g-C3N4s)havecontinuedtoattractattentionasmetal-free,low-cost semiconductorcatalysts.Herein,asystematicsynthesisandcharacterizationofg-C3N4sprepared usingfourconventionalprecursors(urea(U),dicyandiamide(DCDA),semicarbazidehydrochloride (SC-HCl),andthiosemicarbazide(TSC))andanunexploredone(thiosemicarbazidehydrochloride (TSC-HCl))ispresented.Equalsynthesisconditions(e.g.heatingandcoolingrates,temperature, atmosphere,reactortype/volumeetc)mitigatedtheexperimentalerror,offeringfaircomparability foralibraryofg-C3N4s.Thehighestg-C3N4amountpermoleoftheprecursorwasobtainedfor D-C3N4(∼37.85g),whilethelowestwasforS-C3N4(∼0.78g).HCladditiontoTSCincreasedthe g-C3N4productionyield(∼5-fold)andtheoxygencontent(T-C3N4∼3.17%versusTCl-C3N4∼3.80%); however,ithadanegligibleeffectonthelevelofsulphurdoping(T-C3N4∼0.52%versusTClC3N4∼0.45%).S-C3N4wasthedarkestincolor(reddishbrown),andthebandgapenergieswere S-C3N4(2.00eV)<T-C3N4(2.74eV)<TCl-C3N4(2.83eV) D-C3N4(2.84eV)<U-C3N4(2.97eV).The experimentallyderivedconductionbandpositionofS-C3N4(−0.01eV)wasclosertotheFermienergy levelthantheothers,attributabletohighoxygenatomdoping(∼5.11%).S-C3N4displayedthe smallestcrystallitesize(∼3.599nmbyXRD)butthelargestinterlayerdistance(∼0.3269nm). Furthermore,BETsurfaceareaswere138.52(U-C3N4),22.24(D-C3N4),18.63(T-C3N4),10.51 (TCl-C3N4),and9.31m2g−1(S-C3N4).Forthefirsttime,thiscomprehensivehandbookgivesa glimpseofaresearcherplanningg-C3N4-basedresearch.Italsointroducesanoveloxygen-sulphur co-dopedg-C3N4(TCl-C3N4)asanewhalogen-freecatalystwitharelativelyhighproductionyieldper moleofprecursor(∼24.09g).