Recent Advances in Laser-Induced Graphene-Based Electrocatalysts for Water Splitting Reactions

Graphene foams produced by chemical vapor deposition (CVD) and wet-chemical methods offer high surface area but require energy-intensive processing involving high temperatures, pure gases, or harsh chemicals. In contrast, laser-induced graphene (LIG), obtained by direct laser scribing of polyimide (PI) or other carbon-rich substrates, including organic wastes, provides a simple, rapid, and chemical-free route to three-dimensional porous graphene. LIG combines high surface area, tunable porosity, excellent electrical conductivity, mechanical flexibility, and stability, making it an attractive platform for electrochemical energy applications. This review focuses on the role of LIG in water splitting, where it functions both as a metal-free catalyst through heteroatom doping and defect engineering, and as a conductive support for metal-based catalysts. We discuss fabrication strategies, including electrodeposition, in situ and ex situ laser scribing of metal precursors, and MOF-derived approaches, that enable efficient catalysis of the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). We further highlight integrated LIG-based devices for overall water splitting, where monolithic electrochemical cells demonstrate competitive performance compared to benchmarks using noble metals. Finally, we identify key challenges, including control over defect density, dopant concentration, metal oxidation states, and scalable fabrication, and outline future directions such as advanced deposition strategies, theoretical modeling, and device integration. Overall, LIG has emerged as a cost-effective, versatile, and multifunctional platform with strong potential to advance sustainable hydrogen production and next-generation water-splitting technologies.