Selective preparation of Bi2O3 visible light-driven photocatalyst by dispersant and calcination

growthrateofN-dopedb-Bi2O3particlesfrom2hto4hwaslargerthanthatfrom4hto6h(seeFig.15).

Fig.16showsUV–Visdiffusere ectionspectraofthethreeN-dopedb-Bi2O3samples.Theabsorptiondifferenceofthesampleswasquitesmall.Basedonextrapolationprinciple,theabsorptionedgeofN-dopedb-Bi2O3subjectedto6hlocatedat533nm,andthecorrespondingbandgapwas2.45eV.Whentheprecursorwascalcinatedfor4h,theabsorptionedgeshiftedtowards536nmandthebandgapreducedto2.43eV.Whiletheabsorptionedgeandbandgapfor2hwere535nmand2.44eV,respectively(Fig.11).Therefore,whenthecalcinationtimewas4h,the

4.Conclusions

AnewinsightforselectivepreparationofBi2O3photocatalystwithappropriateparticlesizeandcrystallinephasebyusingPEGdispersantandadjustingcalcinationparameterswasproposed.Byinvestigatingin uenceofpreparationconditionsonBi2O3crys-tallinephase,morphologyandotherperformances,N-dopedb-Bi2O3withbestphotocatalyticactivityformalachitegreenwasselectivelyobtainedbyusing2gofPEG1000asdispersantandcal-cinationat350°Cfor4h.Afterilluminationby200W lamentlampfor300min,approximately96.5%ofmalachitegreenwaseliminated.