Controlling oxygen vacancies of WO_x suboxides by ZnWO₄ nanophase hybridization

Substoichiometric tungsten oxide (WO_x, 2 < x < 3) nanomaterials are important nanoscale semiconductor materials with broad applications in optoelectronic devices; however a controllable modification of their physical properties remains challenging task. Here, we report an alternative green synthesis of hybrid nanostructures composed by WO_x and ZnWO₄ phases in ethanol via a solvothermal process using ZnO and WCl₆ as the precursors. The results indicate that the formation of ZnWO₄ leads to the structural conversion of WO_x from nanorods to nanoparticles due to the effect of ZnWO₄ on the side growth of WO_x nanostructures. Moreover, the surface morphology tailored by ZnWO₄ and crystalline phase transformation induce different photoluminescence (PL) emission from pure WO_x nanostructures and WO_x/ZnWO₄ hybrid nanostructures due to the increased number of oxygen vacancies.