Improvement of gaseous pollutant photocatalysis with WO3/TiO2 heterojunctional-electrical layered system

► A novel heterojunctional-electrical layered system for gas-phase photocatalysis. ► The synergistic effect of heterojunction and external low bias is proposed. ► The synergistic effect results in the remarkable improvement of photocatalysis. ► The holes are sufficiently separated and enriched on the surface in this system.