Reduced CuWO4 photocatalysts for photocatalytic non-oxidative coupling of methane reaction

Thermal reduction of the sol-gel derived CuWO4 in an H2-containing atmosphere can drive the Cu phase segment and yield WO3 or oxygen-deficient WO3−x at the same time. The in-situ formed Cu-WO3−x composite owns the advantages of stronger visible light absorption and an in-situ built metal-metal oxide interface, which are beneficial for utilizing the surface plasmon resonance effect of the Cu nanoparticles and providing catalytic active sites. The photocatalytic activity of the non-oxidative coupling of methane is greatly enhanced compared to that of the pristine CuWO4 and physically mixed CuO+WO3, due to the abundant oxygen vacancies and the additional visible light absorbance brought by the Cu nanoparticles