Ag/γ-AgI/Bi2O2CO3/Bi S-scheme heterojunction with enhanced photocatalyst performance

The 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 reducer 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 efficient separation of photoinduced charge carriers. Especially, 30% Ag-AgI/Bi-Bi2O2CO3-OVs exhibits 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 mainly attributes 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.