Fabrication of porous electrodes for green hydrogen evolution: A review of additive manufacturing, laser texturing, dynamic hydrogen bubble templating, powder metallurgy, lithography, and nano-ink printing

• Engineered porosity improves HER via enhanced bubble release and ion transport • Laser texturing, DHBT, and AM enable low overpotentials at high current densities • Hybrid porous electrodes show promise for scalable, stable green H 2 production The rising global energy demand and the environmental impact of fossil-based hydrogen production have increased the urgency for scalable clean energy solutions. Green hydrogen generated through acidic or alkaline water electrolysis offers a sustainable alternative; however, its efficiency is often limited by high overpotentials and mass transport constraints. Recent studies demonstrate that engineered porous electrodes can significantly enhance the hydrogen evolution reaction (HER) by increasing electrochemically active surface area, improving bubble detachment, and facilitating electrolyte transport. This review critically evaluates porous electrode fabrication strategies, including additive manufacturing, laser texturing, dynamic hydrogen bubble templating, powder metallurgy, lithography, and nano-ink printing, with a particular focus on structure–property–performance relationships. Across these approaches, optimized porous architectures consistently demonstrate reduced overpotentials, enhanced stability at high current densities, and improved long-term operational durability. Hierarchical and architected structures, in particular, enable efficient gas management and sustained operation under industrially relevant conditions. At the same time, key challenges remain, including structural reproducibility, long-term mechanical robustness, scalability, and standardized performance benchmarking. By identifying these limitations and emerging knowledge gaps, this review outlines future directions for the development of hybrid and scalable porous electrode designs toward efficient, durable, and industrially viable green hydrogen production.