Synergistically enhanced electronic modulation in trimetallic Cu–Co–Mo-based heterostructured nanomaterials for green H2 production via efficient alkaline electrolysis

Abstract

Trimetallic Cu, Co, and Mo-based bifunctional electrocatalysts have been developed for H₂ production through water electrolysis at a low synthesis cost of $0.051, $0.053 and $0.052 cm⁻² for CuCoMo-LDH, CuCoMo-P and CuCoMo-S, respectively. CuCoMo-LDH, CuCoMo-P and CuCoMo-S required 307, 331 and 311 mV overpotentials for oxygen evolution and 215, 117 and 265 mV for the hydrogen evolution reaction at 50 mA cm⁻², respectively. Density functional theory calculations show that intermediate species migrating to Cu atoms neighboring Co and Mo on the electrocatalyst surface enhance water adsorption. Electronic modulations among the metals boost the density of electronic states near the Fermi level, resulting in higher electrical conductivity. Among the alkaline electrolyzers, CuCoMo-P (±) exhibited the highest overall water splitting performance, requiring the lowest recorded cell potential of 1.393 V at 10 mA cm⁻² followed by CuCoMo-LDH (±) (1.427 V) and CuCoMo-S (±) (1.540 V), all surpassing RuO₂ (+)‖Pt/C (−) (1.554 V). To our knowledge, the use of CuCoMo-P in water electrolysis has not been previously reported. CuCoMo-P (±) achieves 98.7% faradaic efficiency with an H₂ generation rate of 3.4 mL min⁻¹ costing $0.12255 per 1000 L H₂(g). Consequently, the synthesized electrocatalysts are anticipated to significantly advance water electrolysis for large-scale H₂ production.