Electrocatalytic hydrogen evolution performance of RuO2 nanorods grown on top of WO3 nanotube arrays

Water electrolysis has been deemed as a simple, safe, and clean way to realize sustainable hydrogen production. However, efficacious water electrolysis for hydrogen production is highly dependent on efficient and stable electrocatalysts. Herein, we report a nanorod/nanotube array composite as highly efficient electrocatalyst toward hydrogen evolution reaction (HER) in both basic and acidic electrolytes. For the nanorod/nanotube array composite, One-dimensional RuO ₂ nanorods (NRs) were grown on top of WO ₃ nanotube arrays (NTA) through a facile solution impregnation method followed by a high-temperature calcination. The obtained RuO ₂ NRs/WO ₃ NTA demonstrates a superb electrocatalytic activity toward HER in both basic and acidic medias. To achieve a current density of 10 mA cm ^− 2 , the required overpotentials are 33 mV in 1 M KOH and 62 mV in 0.5 M H ₂ SO ₄ , respectively. Furthermore, RuO ₂ NRs/WO ₃ NTA also shows an excellent long-term electrochemical stability in both the acidic and alkaline electrolytes. The electrocatalytic HER activity of RuO ₂ NRs/WO ₃ NTA is superior to most of the reported RuO ₂ -based and Ru-based electrocatalysts, and even comparable to the state-of-the-art Pt/C catalyst. The superb HER activity of RuO ₂ NRs/WO ₃ NTA could be attributed to the structural merits including large surface area with abundant catalytically active sites, specific charge transport channel ensuring enhanced reaction kinetics and favorable bubble formation and release. The present work sheds new light on designing novel one-dimensional composite structures as highly efficient electrocatalyst for sustainable hydrogen generation. Simultaneously, the designed nanorod/nanotube array composite structure in this work is also expected to be applied in other energy conversion devices.