Unraveling the role of metal composition in glycerate-derived Ni–Co–Mo selenides for oxygen evolution electrocatalysis and electrochemical energy storage

Transition metal selenides are promising electrode materials for electrocatalysis and electrochemical energy storage, yet the influence of metal composition on application-specific performance remains unclear. Herein, mono-, binary-, and trimetallic selenides were synthesized via a glycerate-assisted strategy followed by thermal selenization to systematically investigate composition-dependent electrochemical behavior. Binary CoMo–Se exhibited the best oxygen evolution reaction (OER) activity, delivering overpotentials of 353 and 419 mV at 10 and 50 mA cm −2 , respectively, with favorable reaction kinetics and charge-transfer characteristics. In contrast, binary NiMo–Se achieved the highest supercapacitor performance, outperforming trimetallic NiCoMo–Se. These findings demonstrate that increasing the number of metal components does not necessarily improve electrochemical performance, and that the optimal composition depends on the target application. This work establishes clear composition–structure–property relationships and provides design guidelines for multifunctional selenide electrodes for energy conversion and storage.