Photoelectrocatalytic degradation of refractory pollutants over WO3/W network photoelectrode with heterophase junction for enhancing mass transportation and charge separation

The most crucial factors limiting the degradation performance of photoelectrocatalytic (PEC) process are the low charge separation efficiency and slow mass transportation. Herein, we report a WO3 network photoelectrode by constructing heterophase junction of WO3 on tungsten mesh (hm-m-WO3/W mesh), which exhibits superior PEC performance, as high as 5.6 mA cm−2 of photocurrent density at 1.2 VRHE, achieving a complete degradation (99.9%) and nearly total mineralization (84.5%) of bisphenol A, reaching an apparent reaction rate constant of 5.7 × 10−2 min−1, 1.5 times of WO3 based photoelectrode ever reported. A Schottky junction is formed at m-WO3/W interface which greatly promotes the charge transfer between catalysts and support. The catalysts show appropriate phase alignment, where the parallel directions between built-in electric field of heterophase junction and external potential benefit charge separation. Computational fluid dynamics simulations indicate the network structure favors the diffusion of the fluid containing pollutants. This work demonstrates a viable strategy for designing the photoelectrode with high charge separation efficiency and fast mass transportation in PEC wastewater treatment.