Direct solar water splitting driven by inexpensive semiconducting materials is an attractive method to produce hydrogen as a zero-greenhouse gas emission fuel. During the past three decades, however, it has been shown that the main challenge consists in identifying materials that are stable under illumination in aqueous solutions, efficiently absorb sunlight, and induce efficient water splitting. Due to their inherent stability against oxidation and low cost, semiconducting oxides are promising materials to be employed in this process. Unfortunately, relatively fast recombination of photogenerated charge carriers, either in the bulk or at the surface, and slow charge transfer kinetics from the semiconductor to the electrolyte solution restrict their performance.

Due to widely use of fossil fuels, the environmental issues and climate change has been critical global topic. hydrogen fuel cells are clean energy considered to be possible substitutes of fossil fuel. It is even used as powerful rocket fuel for NASA’s space shuttles.

Monoclinic ammonium paratungstate, (APT, NH4)10[H2W12O42]·4H2O ) which will be referred to as APT, is widely used as the industrial feedstock for the production of tungsten carbide, WC for the powder metallurgical production of tungsten filaments, for various tungsten heavy alloys and also as starting material for producing ammonium metatungstate (AMT), which is utilized in the catalyst industry.

Nitrogen oxides (NOx), produced by burning of the biofossil fuels, have been recognized as an air pollutant that can cause a series of NH3-SCR has been demonstrated to be one of the state-of-the-art technologies.