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.

As a hydrogen carrier for long-term sustainable energy supply, urea (CO(NH2)2) has been attracting increasing attention due to its stable, relatively non-toxic, non-flammable and renewable properties. Recently, the electrooxidation of urea has been used as an effective approach for hydrogen production as well as treatment of urea-rich wastewater.However, the current major challenge is to improve the catalytic activity and CO-tolerance of the catalyst.

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.

Employing semiconductor powders as photocatalysis for the degradation of organic pollutants in water has received a lot attention in the last decade. Titanium dioxide (TiO2) inhibits amazing photocatalyst properties including high activity, chemical stability, and low cost. Nevertheless, the photocatalytic activity of TiO2 (with band gap of 3.2 eV and excited by photons with wavelengths under 387 nm) is still limited to irradiation by UV wavelengths, so that photocatalytic process does not occur effectively during the irradiation with solar light as only about 4% of the total radiation of the solar spectrum is in ultraviolet region. Thus, modification of TiO2 in the view to obtain a higher light absorption by shifting absorbance to the visible wavelengths has become the aim of many authors. One of the methods is the coupling of TiO2 with other semiconductors such as TiO2/CdS, TiO2/SnO2, TiO2/ZnO, and TiO2/WO3.