Sustained hydrogen production through alkaline water electrolysis using Bridgman–Stockbarger derived indium-impregnated copper chromium selenospinel

Abstract

The depletion of conventional fossil fuels necessitates the development of sustainable energy alternatives, with electrochemical water splitting for hydrogen (H<inf>2</inf>) production being a promising solution. However, large-scale hydrogen generation is hindered by the scarcity of cost-effective electrocatalysts to replace noble metals such as Pt and RuO<inf>2</inf> in the Oxygen Evolution Reaction (OER) and Hydrogen Evolution Reaction (HER). In this study, we report the synthesis of CuCr<inf>2-x</inf>In<inf>x</inf>Se<inf>4</inf> (x = 0, 0.2, 0.4) using a dual approach combining the Bridgman-Stockbarger method and ball milling. Among the synthesized materials, CuCr<inf>1.8</inf>In<inf>0.2</inf>Se<inf>4</inf> demonstrates outstanding HER activity in 1.0 M KOH, achieving a potential of ?0.16 V vs. RHE at a current density of 10 mA cm?2. Moreover, the material shows remarkable durability during a three-electrode accelerated degradation test in an alkaline medium, maintaining its performance over 24 h at a constant current density of ?200 mA cm?2, with a stable potential of ?0.57 V vs. RHE. Additionally, CuCr<inf>1.8</inf>In<inf>0.2</inf>Se<inf>4</inf> was tested in a two-electrode configuration alongside CoFe LDH, achieving a benchmark of 1.7 V for overall water splitting. It sustained a current density of 400 mA cm?2 for 24 h in an accelerated degradation test, exhibiting a minimal loss of 0.1 V after the testing period. These results highlight CuCr<inf>1.8</inf>In<inf>0.2</inf>Se<inf>4</inf> as a promising non-noble metal catalyst for HER, demonstrating its potential to reduce reliance on noble materials for large-scale hydrogen production. © 2024 Hydrogen Energy Publications LLC