Dual S-scheme Bi2MoO6/g-C3N4/Ag2MoO4 ternary heterojunction: Interfacial charge transfer, broadband spectrum, enhanced redox ability

A ternary heterojunction bearing Bi2MoO6 and g-C3N4 is deposited on Ag2MoO4 for the photocatalytic degradation of sulfamethoxazole (SMX) antibiotic. Though the hydrothermal synthesis is non-directional, the dual Sscheme heterojunction formation is governed by the g-C3N4 serving as an electron bridge between Bi2MoO6 and Ag2MoO4. The potent strong interaction with both Bi2MoO6 and Ag2MoO4 facilitates high oxidation and reduction potential. The optimized Bi2MoO6/g-C3N4/Ag2MoO4 heterojunction with extended visible light absorption exhibits 96 % SMX degradation efficiency within 240 min of irradiations. The dual S-scheme configuration endows in-built electric field with vigorous driving force for charge carrier separation. The charge transfer mechanisms were validated by the photoluminescence results. Bi2MoO6/g-C3N4/Ag2MoO4 MoO 4 heterojunction demonstrates pseudo-first order kinetics with 0.143 kmin(-1) for SMX degradation and ternary photo-catalyst 83 % degraded SMX after successive five cycles. In the formed dual S-scheme Bi2MoO6/g-C3N4/Ag2MoO4 heterojunction, (OH)-O-center dot and center dot O-2(-) radicals were the main reactive species for SMX degradation. This research contributes to the formation of stable multicomponent photocatalytic systems.