Dimension-dependent heterostructure catalysts for acidic oxygen evolution reaction: Challenges and prospects

The oxygen evolution reaction (OER) is a crucial half-reaction in water splitting, which is essential to produce hydrogen through electrolysis. However, the sluggish dynamics and large overpotential of OER, particularly in acidic electrolytes, remain significant challenges for efficient energy conversion. Recent advancements in dimension-dependent heterostructure catalysts have demonstrated remarkable progress in addressing these issues. By integrating materials with distinct dimensionalities, ranging from 0D nanoparticles to 3D porous frameworks, these heterostructures optimize electronic properties, facilitate electron transfer and expose more active surface, leading to superior catalytic performance. The fundamental pathways of OER are discussed, including the lattice oxygen mechanism (LOM), adsorbate evolution mechanism (AEM), and oxide path mechanism (OPM), and the importance of dimensional engineering in designing efficient catalysts is emphasized. Furthermore, various synthetic strategies, structural modifications like doping and defect engineering, and the role of carbon-based materials as cost-effective and durable catalyst supports in enhancing OER performance are addressed. This review provides a comprehensive framework for constructing next-generation OER catalysts for sustainable energy applications with superior performance in acidic environments.