Hydrogen Production by Electrolysis and Photoelectrochemical System

Abstract Hydrogen energy has been drawing much attention in renewable energy technologies. Hydrogen production by water splitting reaction has especially been widely studied as an environmentally friendly and sustainable energy source. Realization of cost‐effective hydrogen production by water splitting requires electrolysis or photoelectrochemical cells decorated with highly efficient cocatalysts. Here, we briefly summarize the theory of water splitting reaction and discuss various types of catalysts for water splitting reaction (hydrogen evolution reaction and oxygen evolution reaction). Principles of photoelectrochemical hydrogen evolution from light absorbing semiconductors will be described.