High-Performance 3D Semiconductor-Based Heterostructure Photocatalyst in Sustained Control of Harmful Gas-Phase Pollutants Under Visible-Light Illumination

Herein, a highly efficient three-dimensional (3D) semiconductor-based heterostructure photocatalyst (i.e., WO3–g-C3N4 monolithic architecture; WOCNM) was developed by immobilizing a WO3–g-C3N4 heterostructure powder on a melamine foam (MF) framework. Subsequently, the sustained control of two harmful model gas-phase pollutants (i.e., n-butanol and o-xylene) over WOCNM and selected monolithic counterparts (i.e., MF-supported WO3 monolith and MF-supported g-C3N4 monolith) was investigated under visible-light irradiation. WOCNM exhibited higher photocatalytic capabilities in the sustained control of the two model pollutants than those of individual WO3 and g-C3N4 monoliths because the WO3–g-C3N4 heterojunction enhanced its charge-separation ability. Notably, WOCNM exhibited highly efficient photocatalytic capabilities in the sustained control of n-butanol (up to 97%) and o-xylene (up to 86%). Moreover, no noticeable changes were observed in the WOCNM photocatalytic capability after the final run of successive applications. The fresh and successively used WOCNMs were nearly identical, and the photocatalyst powder was not observed in the reaction chamber after its successive application. As a result, WOCNM was a highly efficient and stable 3D heterostructure photocatalyst for the sustained control of gas-phase n-butanol and o-xylene, without significant catalyst powder loss. Promisingly, this study will expedite the future development of 3D photocatalysts for the sustained control of harmful gas-phase pollutants.