2D/2D/2D CuO-MXene-OCN heterojunction with enhanced photocatalytic removal of pharmaceuticals and personal care products: Characterization, efficiency and mechanism

Limit caused by insufficient charge transfer between interfaces is one of the current topics in the photocatalytic degradation of pharmaceuticals and personal care products (PPCPs). Photocatalysts designed as 2D/2D/2D structures have a faster separation rate of the heterojunction interface and a better carrier transfer speed to improve their performance. In this work, 2D CuO nanosheets have been synthesized by the drip method at normal temperature. And layered MXenes are introduced as the charge transfer bridges into the system of O-doped g-C3N4 nanosheets and CuO nanosheets to construct a 2D/2D/2D CuO-MXene-OCN S-scheme heterojunction. The photocatalytic performance of CuO-MXene-OCN is much higher than CuO-OCN heterojunction due to the intimate interaction between interfaces. The degradation efficiencies of different PPCPs in 60 min under visible light irradiation are 98.2 % for TC, 75.6 % for MT, 92.6 % for DCF. This unique interfacial engineering gives new insight into the construction of layered S-scheme heterojunctions with 2D/2D/2D structure for photocatalytic degradation of PPCPs.