Strategically coupled tungsten oxide-zinc oxide photosystems for solar-driven nerve agent simulant degradation and hydrogen evolution

In response to the urgent need for environmental remediation and sustainable energy sources, this study focuses on the multidimensional aspects of solar-driven decontamination of hazardous materials and hydrogen (H₂) generation. To achieve these objectives, ZnO and WO₃ particles were coupled through two distinct strategies, resulting in the formation of morphologically and characteristically distinguished ZWO-I and ZWO-II photosystems. The addition of Hexamethylenetetramine (HMTA) in a particular reaction step played a crucial role in facilitating the fabrication of the desired products. ZWO-I photosystem was formed by the fusion of ZnO and WO₃, yielding pseudo octahedral ZnWO₄ microparticles. On the other hand, the ZWO-II photosystem was obtained by decorating WO₃ nanoparticles (NPs) onto quasi-aligned ZnO nanorods (NRs). Both multifunctional photosystems exhibited remarkable efficiency in solar-driven nerve agent simulants (diethyl methylphosphonate (DEMP)) degradation and hydrogen production while maintaining excellent photostability and recyclability. Notably, the ZWO-II outperformed the ZWO-I photosystem due to the facile construction of type-II heterojunction between ZnO NRs and WO₃ NPs at the interface. This study demonstrates the promising potential of ZnO-WO₃ coupled photosystems for efficient solar-driven degradation of hazardous materials and sustainable green H₂ production.