Electrospun Transition Metal Nanofibers for Electrocatalytic Water Splitting: Structural Design, Performance Regulation, and Prospects

Electrocatalytic water splitting is a key technology for green hydrogen production. It is severely limited by the sluggish kinetics of the oxygen evolution reaction and the hydrogen evolution reaction. Transition metal elements are abundant in the earth's crust and have tunable electronic structures. However, their catalysts exhibit insufficient active sites, poor electrical conductivity, and low stability. Electrospinning technology offers simple preparation, unique one-dimensional features, and high controllability over composition and morphology. Therefore, it has become an important platform for constructing high-performance electrocatalysts for water electrolysis.This review starts from the principles and preparation of electrospun nanofibers. The basic reaction mechanisms of HER and OER are introduced. Three core structural design strategies are systematically summarized: porous structures, hollow/core-shell structures, and heterojunction structures. How electrospinning technology regulates active site exposure, charge transport efficiency, and electronic structure of transition metal catalysts is deeply analyzed. Finally, the challenges and prospects for further development of electrospun nanofiber materials in water splitting electrocatalysts are discussed. Special emphasis is placed on theoretical calculation-assisted design and performance evaluation under high current densities.