Electrodeposition of multi component alloys for hydrogen evolution reaction – A review

Green hydrogen is a clean, renewable energy carrier crucial to global decarbonization goals. However, its production is limited by the high cost and limited availability of efficient electrocatalysts, traditionally based on noble metals like Pt, Pd, and Ir. High entropy alloys (HEAs) have recently emerged as cost-effective alternatives with comparable electrocatalytic properties. Among various synthesis methods, electrodeposition offers a low-cost, energy-efficient route for fabricating multicomponent alloy electrocatalysts. While existing literature addresses fragmented aspects of electrodeposition, this review provides a comprehensive overview of co-deposition mechanisms, key parameters, and their influence on HER activity. Importantly, the review identifies critical research gaps. This include the challenges in achieving equimolar deposits, the need for thickness and mass loading optimization, mechanistic studies of redox irreversibility, and the role of complexing agents that offer significant insights in the electrodeposition studies. • Reviews electrodeposition as a cost-effective, energy-efficient approach for multicomponent electrocatalyst synthesis. • Summarizes key co-deposition parameters. • Identifies various complexities in electrodeposition of multicomponent alloys and states the future scope. • Highlights the synthesis and Hydrogen Evolution Reaction performance of electrodeposited high-entropy alloys (HEAs).