Optimized trimetallic selenide heterostructures as high-performance trifunctional electrodes for self-sustained hydrogen production

Abstract

The growing need for integrating energy storage and conversion devices highlights the crucial role of multifunctional electrodes in advancing renewable energy technologies and reducing carbon emissions. Herein, we introduce nitrogen-doped trimetallic selenides that comprise Ni₃Se₂, Co_0.85Se, and MoSe₂ heterostructures on 3D nickel foam, synthesized via a one-step selenization process (denoted as N-NCM-Se) serving as highly effective trifunctional electrodes, demonstrating exceptional electrochemical performance in the hydrogen evolution reaction (HER), the oxygen evolution reaction (OER) and supercapacitors (SCs). The optimized N-NCM-Se electrode exhibits low HER and OER overpotentials of 75/157 mV and 286/356 mV, respectively, and an overall water splitting potential of 1.57/1.68 V at current densities of 100/500 mA cm⁻² when used as a bifunctional electrode in alkaline electrolytes. As a cathode material for asymmetric supercapacitors (ASCs), N-NCM-Se delivers a high specific capacitance of 207 F g⁻¹ and a maximum energy density of 73.5 W h kg⁻¹. The outstanding electrocatalytic performance is attributed to the strong synergistic interactions at the trimetallic selenide heterointerfaces and enhanced electronic conductivity, which can increase the catalytic site exposure and charge transfer. Finally, the N-NCM-Se electrode was successfully integrated into a self-powered device, coupling water-splitting with ASCs, marking a significant advancement in multifunctional electrodes for energy storage and conversion technologies.