Enhanced sulfamethoxazole photodegradation by N-SrTiO3/NH4V4O10 S-scheme photocatalyst: DFT calculation and photocatalytic mechanism insight

In this study, we synthesized a N-SrTiO3/NH4V4O10 S-scheme photocatalyst by modifying NH4V4O10 nanosheets with various proportions of N-doped SrTiO3 nanoparticles using a mild hydrothermal method.Density Functional Theory(DFT) calculations were employed to elucidate thephotocatalytic mechanism, while the electron-hole transfer and separation of the S-type heterojunction were further characterized experimentally. The photocatalyst was applied to the photodegradation of sulfamethoxazole (SMX), a common water pollutant. Among all the prepared photocatalysts, 30 wt% N-SrTiO3/NH4V4O10 (NSN-30) displayed the highest photocatalytic performance. This was attributed to the facile electron transfer mechanism of the S-scheme heterojunction, which facilitated the effective separation of electron-holes and preserved the strong redox property of the catalyst. The possible intermediates anddegradation pathwaysin thephotocatalytic systemwere explored usingelectron paramagnetic resonance(EPR) and DFT calculations. Our findings demonstrate the potential of semiconductor catalysts to remove antibiotics from aqueous environments usinggreen energy.