Integrated heterojunction boosts robust photothermocatalytic VOCs degradation

Integrated heterojunction photocatalyst design concept is proposed. • Integrated heterojunction Bi/Bi2-xWO6-y is designed by in situ surface segregation. • Efficient photoinduced charges interfacial transfer and separation is obtained. • Hierarchical use of full spectrum light is boosted. • Prominent photothermocatalytic VOCs degradation performance is recorded. Development of robust photocatalysts for effectively treating complex environmental pollutants via utilizing full spectrum sunlight has been a highly desirable yet challenging project. Although the design of multicomponent or multiphase heterojunctions holds the potential, it still suffers from the unsatisfied charges migration and separation caused by interfacial incompatibility among heterojunction components. Herein, the integrated heterojunction photocatalyst design concept is proposed to conquer such challenge, in which the components of the heterojunction are tightly connected by “pseudo-single-phase” interfaces to realize efficient interfacial charge transfer. As an example, the defective bismuth tungstate nanosheets (Bi 2-x WO 6-y ) loaded with small-sized homologous Bi metal nanoparticles were synthesized via an in situ surface segregation method, namely Schottky integrated heterojunction H-Bi/VBWO. H-Bi/VBWO not only exhibits strong electronic interactions, which reduce the directional migration barrier of photogenerated charges, but also achieves hierarchical utilization of full spectrum light, resulting in the boosted production of energetic photoinduced charges by enhanced UV–vis absorption (via Bi/O vacancies & plasmonic Bi NPs) and robust photothermal effect caused by NIR absorption (via plasmonic Bi NPs & W 5+ ). The H-Bi/VBWO demonstrates robust photothermal catalytic VOCs degradation under simulated standard sunlight (AM1.5, 100 mW/cm 2 ) without external heat, ranging among the best of state-of-the-art photocatalysts and photothermocatalysts. Such an integrated heterojunction design concept provides a promising way for the design of robust photocatalysts for environmental application. Download: Download high-res image (163KB) Download: Download full-size image