Modification And Photocatalytic Performance Research Of Bismuth Oxycarbonate Photocatalyst With Visible-Light-Driven

Bi2O2CO3 has received better attention due to its diverse structures,simple preparation methods,and strong visible light response.However,the wide band gap and low quantum efficiency of Bi2O2CO3-based photocatalysts limit their performance improvement.Based on two modification techniques,defect regulation and crystal face exposure,this work promotes the exposure of more active sites of Bi2O2CO3-based semiconductor photocatalysts during the degradation process,improves their utilization of visible light,and promotes the separation of photogenerated carriers.The main research contents are as follows:Metal defect engineering is the crux to accomplish the goal of local electronic regulation,which is an important factor for visible light to drive photocatalyst performance.In this paper,the solvothermal-precipitation method was used to reduce Bi in situ via the glucose to construct Ag-AgI/Bi-Bi2O2CO3-OVs heterojunction.The Ag-AgI/Bi-Bi2O2CO3-OVs composite photocatalyst has excellent photoresponse ability and fast charge carrier separation.In addition,the powerful S-scheme heterojunction retains the original redox capability of the components.The unique lawn-like structure exhibits favorable surface scattering and reflection,which promotes the efficient separation of photoinduced charge carriers.Especially,30%Ag-AgI/Bi-Bi2O2CO3-OVs exhibit brilliant photocatalytic performance for the degradation of tetracycline,which is 4.85 times and 1.15 times higher than the original Bi2O2CO3 and AgI,respectively.The enhanced photocatalytic activity is mainly attributed to the presence of oxygen vacancies,the sensitization of Ag-AgI,the double surface plasmon resonance(SPR)effect,and the heterogeneous interface due to the improved morphology,which effectively inhibits the recombination of electron-hole pairs.This work provides a new perspective for the reasonable construction and simple synthesis of high-performance Bi-based semiconductor photocatalysts.Appropriate interfacial contact and defect engineering in heterojunction materials play a key role in enhancing photocatalytic activity.In this article,Bi2O2CO3/g-C3N4 S-scheme heterojunction photocatalysts linked by carbon bridges were synthesized by a hydrothermal method.Among them,the carboxylated carbon nanotubes,as a bridge,have excellent electrochemical energy storage performance and favorable stability.The FCNT-Bi2O2CO3/30%-g-C3N4 exhibited the best photocatalytic degradation activity(96%)for tetracycline hydrochloride under visible light irradiation.The enhancement of photocatalytic performance may be due to the generation of latent defects in the system caused by the doping of nanotubes,and the exposure of {001} crystal planes to induce bulk defects,which in turn promotes the separation of photogenerated charge carriers.Moreover,the obtained FCNT-Bi2O2CO3/g-C3N4 S-scheme heterojunction photocatalysts perform better than pure g-C3N4 and Bi2O2CO3.Furthermore,the formation and practical application of composite heterostructures are discussed in detail,providing new insights into the design and construction of novel S-scheme heterojunction photocatalysts.