Hydrogen Production Technologies from Water Decomposition: A Review

Hydrogen is a promising energy carrier in the future, which can help improve air quality and enhance energy security. Hydrogen production mainly relies on fossil fuels (natural gas and coal). Hydrogen production from fossil fuels can result in the significant emissions of carbon dioxide, aggravating the global greenhouse effect. At the same time, fossil fuels are non-renewable, and the use of fossil fuels to produce hydrogen further exacerbates the crisis of fossil fuel shortages. Fortunately, water, as a carbon-free and hydrogen-rich renewable resource, offers one of the best solutions to replace hydrogen production from fossil fuels through its decomposition. Furthermore, hydrogen production by decomposition of water is vital for the realization of the sustainable development. In this paper, we review the current mainstream technologies (electrolysis, pyrolysis and photolysis) for hydrogen production by decomposing water. The principles, processes, advantages and disadvantages and the latest progresses of these technologies are also discussed. At last, this paper provides a summary and outlook on water decomposition for hydrogen production, and thinks that the yield, energy efficiency and cost of hydrogen production from water decomposition are largely dependent on the development of new materials and the improvement of existing materials. Moreover, utilizing renewable energy to decompose water for hydrogen production offers the possibility of achieving the hydrogen economy.