Unveiling S-Scheme Bi2WO6@Black-TiO2 Heterostructure for Superior Photoelectrocatalytic Water Remediation

Abstract

Developing targeted functionalized photoelectrodes based on charge transfer kinetics is a pivotal strategy to achieve efficient photoelectrocatalytic (PEC) process. Herein, Bi₂WO₆@Black-TiO₂ hierarchical heterogeneous network architectures are prepared by coupling Bi₂WO₆ nanosheets with a three-dimensional B(black)-TiO₂ network structure via a sequence simple hydrothermal/solvothermal strategy for application in water pollution remediation. The optimized Bi₂WO₆@B-TiO₂-2.0 photoelectrode exhibits excellent PEC degradation efficiency for sulfamethoxazole and various organic pollutants, including reactive brilliant blue KN-R, rhodamine B, and bisphenol A. And the Bi₂WO₆@B-TiO₂-2.0 photoelectrode also demonstrated well catalytic stability by long-term stability and recycling experiments, which can be attributed to its unique nanonetwork structure bringing an abundance of active sites. Furthermore, a S-Scheme carriers transfer mechanism with solid ability to induce long lifetime electron/hole with strong redox, was identified via in situ x-ray photoelectron spectroscopy and time-resolved photoluminescence, resulting in the efficient production of active species (·OH and·O₂⁻) to achieve superior PEC degradation efficiency. The work reveals Bi₂WO₆@B-TiO₂-2.0 as promising catalysts for water remediation but also unlocks that S-Scheme heterojunctions facilitate carrier transport and utilization, guiding the designing of heterojunctions for other optoelectronic applications.