Synergistic photocatalytic removal of U(VI) and tetracycline over a dual Z-scheme g-C3N4/Bi2MoO6/Bi2WO6 heterojunction

A g-C 3 N 4 /Bi 2 MoO 6 /Bi 2 WO 6 ternary heterojunction was constructed via simple mechanical grinding and thermal treatment. • GBMW follows a dual Z -scheme charge-transfer pathway, preserving strong redox capability for enhanced photocatalysis. • U(VI) acts as an electron acceptor to promote charge separation and improve photocatalytic performance. Due to the difficulty of conventional photocatalytic systems in simultaneously achieving strong oxidation and reduction processes, the treatment of wastewater containing coexisting uranium and organic pollutants remains a critical challenge in the field of photocatalysis. Herein, a novel g-C 3 N 4 /Bi 2 MoO 6 /Bi 2 WO 6 (GBMW) ternary photocatalyst with a dual Z -scheme heterojunction architecture was rationally constructed for the removal of U(VI) and tetracycline (TC) under visible-light irradiation. The dual Z-scheme heterojunction extends the visible-light response range and accelerates interfacial charge transfer, while preserving strong redox potentials. Within 100 min, GBMW achieves a U(VI) reduction efficiency of 91.6% and a TC degradation efficiency of 97.6%, with corresponding k obs values of 0.02332 and 0.03664 min −1 , respectively, which are significantly superior to those of BiMO, BiWO, GCN and GBW. Notably, U(VI) can act as an efficient electron acceptor to promote the separation of electrons and holes in GBMW, which significantly facilitates the degradation of TC. Moreover, GBMW demonstrates excellent stability and anti-interference performance in various real water matrices. This work not only provides a feasible strategy for constructing high-efficiency dual Z -scheme heterojunctions photocatalysts, but also offers an effective solution for treating complex wastewater containing coexisting organic pollutants and radioactive contaminants. Download: Download high-res image (264KB) Download: Download full-size image