As the demands for solar energy, pure air and water, and disposing of poisonous and hazardous pollutant are increasing, the use of semiconductor photocatalysts for environmental purification has attracted considerable attention due to their applicability for the removal of a wide variety of pollutants. Especially TiO2 has been studied widely in virtue of the high photocatalytic activity for organic pollutants such as RhB, tetracycline, phenol, and methylene blue under UV irradiation. Although TiO2 has various merits, the practical application of TiO2 is limited by its low photon utilization efficiency and the need for an ultraviolet excitation source which accounts for only a small fraction of solar light (approximately 5%).

Cobalt tungstate (CoWO4) with monoclinic wolframite structure has been used in a wide range of potential applications including supercapacitors, photocatalysts, catalyst for oxygen evolution reaction (OER) and hydrogen production, microwave dielectric ceramics, photovoltaic electrochemical cells, among others. As electrochemical energy storage devices, batteries and supercapacitors have attracted significant attention due to their intrinsic characteristics of energy and power densities, cycling stabilities and charging-discharging rates.

Currently, due to the environmental situation worsening, in various countries and especially in the large cities, more and more funds have been allocated for the development of the green energy industry and environmentally friendly technologies. Hydrogen energy is an energy source that has increased its popularity in recent years. It is a clean energy source that can be used instead of fossil fuels. Hydrogen it can be used instead of fossil fuels due to its higher energy content and less environmental impact. The density of hydrogen is lower than the density of air. The gravimetric density of hydrogen energy is generally about seven times higher than the density of fossil fuels.

A fabrication process of tungsten oxide (WO3) nanoplates with ammonium paratungstate has been performed, the product showed great photocatalytic activity due to the plate-like shape. Tungsten oxide (WO3) is a promising candidate for semiconductor gas sensors, electrochromic devices and photocatalysts. Structure and morphology of WO3 have obvious influences on its properties and applications. It has been reported that tungsten oxide with mixed structures exhibits poor optical properties, whereas the single-structure tungsten oxide, either hexagonal or cubic, exhibits noticeable absorption capacity.