Electrochemically deposited quaternary copper-selenium-nickel-cobalt layer electrocatalysts on lyocell-based carbon cloth for the construction of stable overall water splitting

Controlling the interaction between the anchoring metals and the support has been identified as an effective technique for improving electrocatalytic performance by modifying the electrical structure at the interface. However, the development of distinct support and the insight into interfacial electron accumulation in influencing reaction kinetics remain challenging to achieve. We hereby describe the fabrication of hierarchically structured multi-element electrocatalysts for water splitting, composed of copper (Cu), selenium (Se), nickel (Ni), and cobalt (Co), employing an electrodeposition approach on lyocell-carbon cloth (CuSeNiCo@lyocell-CC). The electrocatalyst takes advantage of its carefully designed nanoarchitecture, which features numerous exposed active sites, abundant charge transfer pathways, and significant porosity to facilitate the release of gas bubbles. The optimized electrodeposited CuSeNiCo@lyocell-CC composite exhibits low overpotentials of 250 mV for the OER and 185 mV for the HER at a current density of 20 mA cm⁻², accompanied by Tafel slopes of 59.3 mV dec⁻¹ for the HER and 65.0 mV dec⁻¹ for the OER. Using these catalysts as anode and cathode electrodes makes it possible to achieve small cell voltages of 1.58 V at current densities of 10 mA cm^-2, allowing for a sustained overall water-splitting process. In addition, it revealed significant durability after prolonged water-splitting activities lasting >50 h. The findings of this study are especially useful for practical applications of the water oxidation process, as they provide precise and insightful information on the preliminary development of robust and effective multifunctional electrocatalysts for total water splitting. This study suggests a strategy for improving multi-element catalysts.