Recent Updates in Direct Radiation Water-splitting Methods of Hydrogen Production

The exploration of green energy is a demanding issue due to climate change and ecology. Green energy hydrogen is gaining importance in the area of alternative energy sources. Many methods are being explored for this but most of them are utilizing other sources of energy to produce hydrogen. Therefore, these approaches are not economic and acceptable at the industrial level. Sunlight and nuclear radiation as free or low-cost energy sources to split water for hydrogen. These methods are gaining importance in recent times. Therefore, attempts are made to explore the latest updates in direct radiation water-splitting methods of hydrogen production. This article discusses the advances made in green hydrogen production by water splitting using visible and UV radiations as these are freely available in the solar spectrum. Besides, water splitting by gamma radiation (a low-cost energy source) is also reviewed. Eforts are also made to describe the water-splitting mechanism in photo- and gamma-mediated water splitting. In addition to these, challenges and future perspectives have also been discussed to make this article useful for further advanced research.