ABSTRACT The growing global energy demand and environmental crisis require carbon‐neutral energy solutions. Hydrogen is an attractive energy carrier due to its high gravimetric energy density and clean combustion. Conventional methods such as steam reforming and electrolysis are constrained by fossil dependence, high energy input, and CO 2 emissions. However, the photocatalytic (PC) water splitting offers a sustainable solar‐driven alternative but remains limited by the scarcity of efficient, stable, and earth‐abundant catalysts. Metal‐organic frameworks have recently emerged as a promising photocatalyst due to their structural tunability, large surface areas, and ability to integrate light‐absorbing linkers with catalytically active metal centers. In particular, nickel‐based metal‐organic frameworks (MOFs) contain the abundance and redox activity of Ni with highly tailorable coordination environments, offering unique opportunities to tune band structures, enhance charge separation, and promote surface reactivity. The PC efficacy of Ni‐MOFs‐based catalysts was also modulated by linker functionalization, heterojunction engineering, and co‐catalyst integration. Hence, the present review critically evaluates the design strategies, mechanistic insights, and performance of Ni‐MOFs‐based photocatalysts for hydrogen production, with emphasis on band alignment, charge‐carrier dynamics, stability, and scalability. By combining theoretical and experimental perspectives, authors highlight future directions to unlock the potential of Ni‐MOFs as next‐generation photocatalysts for a sustainable hydrogen economy.
Tyagi et al. (Thu,) studied this question.