Exploring Metal Oxides Nanostructures for Sustainable Hydrogen Evolution via Indoor Electrocatalytic Water Splitting

The widespread adoption of green hydrogen production plays a pivotal role in establishing a sustainable circular economy. A major challenge lies in the efficient production of hydrogen to meet the demands of commercial scale applications. Hydrogen production through water electrolysis is an effective method to utilize surplus renewable energy efficiently, offering advantages in energy conversion and storage, where catalysis or electrocatalysis plays a pivotal role. The development of active, cost effective, and stable catalysts or electrocatalysts is a critical prerequisite for efficient electrocatalytic hydrogen production from water splitting for practical applications, which is primary focus of this review. On the one hand, precious metals are commonly utilized to investigate the two half-cell reactions namely the HER and OER. However, the use of precious metals such as Au, Ag, Pt, Ru, as electrocatalysts, is limited by their cost and less availability, hindering their practical application. In contrast, non-precious metal-based electrocatalysts are abundant, environmentally friendly, and low-cost, which demonstrating high electrical conductivity and electrocatalytic performance comparable to noble metals. Thus, these electrocatalysts have the potential to replace precious metals in the water electrolysis process. In this review, we present key fundamental insights into water electrolysis, which not only enables higher hydrogen production but is also cost-effective.