Enhanced visible light PMS activation through novel direct Z-scheme heterojunction of N-doped TiO2 and O-laden g-C3N4

A novel direct Z-scheme heterojunction (NTMO) was synthesized via N-doped TiO 2 and O-doped carbon nitride integration, exhibiting exceptional visible-light photoactivity. Elemental doping narrowed the bandgap and improved the separation efficiency of photo-induced carriers in the heterojunction. Especially, O doping enhanced the adsorption capacity of the heterojunction for PMS, indicating that the presence of O could improve PMS activation through photo-induced electron. The NTMO/PMS system achieved 99.0 % trichloroethylene (TCE) degradation within 1 h 4.7 times and 2.4 times faster than pure TiO 2 and MCN, respectively. Mechanistic studies identified •SO 4 – and h + as dominant reactive species. Furthermore, NTMO exhibited high stability after five cycles of testing. This work provides an efficient visible-light-driven strategy for persistent organic pollutant remediation. • N and O doping narrowed the bandgap and enhanced photo-induced carrier separation in the heterojunction. • Photo-induced e – transfer from (0.5)N-T to MCN-O via a built-in electric field, forming a direct Z-scheme heterojunction. • Doping enhanced the adsorption capacity of the heterojunction for PMS.