Abstract: Electrochemical water splitting represents a sustainable technology for hydrogen (H2) production. However, its large-scale implementation is hindered by the high overpotentials required for both the cathodic hydrogen evolution reaction (HER) and the anodic oxygen evolution reaction (OER). Transition metal-based catalysts have garnered significant research interest as promising alternatives to noble-metal catalysts, owing to their low cost, tunable composition, and noble-metal-like catalytic activity. Nevertheless, systematic reviews on their application as bifunctional catalysts for overall water splitting (OWS) are still limited. This review comprehensively outlines the principal categories of bifunctional transition metal electrocatalysts derived from electrospun nanofibers (NFs), including metals, oxides, phosphides, sulfides, and carbides. Key strategies for enhancing their catalytic performance are systematically summarized, such as heterointerface engineering, heteroatom doping, metal-nonmetal-metal bridging architectures, and single-atom site design. Finally, current challenges and future research directions are discussed, aiming to provide insightful perspectives for the rational design of high-performance electrocatalysts for OWS.

Key words: Electrospinning; Nanofibers, Transition-metal-based catalysts, Overall water splitting, Performance optimization