Hydrogen-bond based charge bridge in a heterojunction system for the synergistic degradation and detoxification of two PPCPs

Abstract

The use of photocatalysis to remove pharmaceuticals and personal care products (PPCPs) is emerging as a promising method, but few studies have investigated the simultaneous degradation of multiple PPCPs. Here, we constructed a hydrogen-bonded bridged MIL-101(Cr)–NH2/BiOCl-OH (MCN/BOCH) system to degrade sulfamethoxazole and ethyl p-aminobenzoate alone or in combination. The MCN/BOCH system effectively removed two PPCPs under visible light and exerted a synergistic effect on degrading the combined pollutants. Meanwhile, the degradation products of the mixture changed significantly compared with that of a single pollutant, and the toxicity of the composite pollutants was significantly reduced through the combined effect of synergistic degradation. The bridging of hydrogen bonds effectively accelerated charge transfer at the heterojunction interface under visible light. Moreover, the separated redox side of the MCN/BOCH heterojunction system and the electron donor and acceptor effect of the two PPCPs significantly enhanced the synergistic photocatalytic degradation performance. This work might be useful for controllable designs of hydrogen-bonded photocatalysts for the treatment of complex PPCP pollution.