One-step hydrothermal synthesis of a novel 3D BiFeWOx/Bi2WO6 composite with superior visible-light photocatalytic activity

Abstract

A novel 3D BiFeWO_x/Bi₂WO₆ (BFW/BWO) composite has been synthesized via a facile one-pot hydrothermal process. A tight chemically bonded interface between the BFW and BWO could be constructed by this simple and environmentally benign method. The composite structures and chemical properties were investigated by XRD, FE-SEM, HR-TEM and EDS. The photocatalytic performances of the as-synthesized materials were assessed by photocatalytic oxidation (PCO) of NO under visible light illumination. The optimum BFW/BWO-1 composite exhibited 87% PCO efficiency, which was higher than that of the single phase BWO and BFW. The enhancement of the photocatalytic activity of the BFW/BWO-1 composite was ascribed to the effective separation and reduced recombination rate of the photoinduced charge carriers, evinced by transient photocurrent, EIS and PL measurements. The radical trapping experiment and DMPO spin-trapping ESR measurement revealed that H⁺ and ˙OH were the important active species. The tests for stability and recyclability revealed that the BFW/BWO-1 composite could be a desired photocatalyst for the oxidation of NO in the ecosystem. The kinetics and possible mechanism for the PCO of NO on the BFW/BWO-1 composites were discussed.