As a secondary energy with great commercialization potential

hydrogen energy has been widely studied due to the high calorific value

clean combustion products and various reduction methods. At present

the blueprint of hydrogen energy economy in the world is gradually taking shape. Compared with the traditional high-energy consuming methane steam reforming hydrogen production method

the electrocatalytic water splitting hydrogen production stands out among other process of hydrogen production owning to the mild reaction conditions

high-purity hydrogen generation and sustainable production process. Basing on current technical economy situation

the highly electric power cost limits the further promotion of electrocatalytic water splitting hydrogen production process. Consequently

the rational design and development of low overpotential and high stability electrocatalytic water splitting catalysts are critical toward the realization of low-cost hydrogen production technology. In this review

we summarize the existing hydrogen production methods

elaborate the reaction mechanism of the electrocatalytic water splitting reaction under acidic and alkaline conditions and the recent progress of the respective catalysts for the two half-reactions. The structure–activity relationship of the catalyst was deep-going discussed

together with the prospects of electrocatalytic water splitting and the current challenges

aiming at provide insights for electrocatalytic water splitting catalyst development and its industrial applications.