The Electrolytic Water Performances of CuNi Alloy Foil Under the Surface Acoustic Waves

Hydrogen production via water electrolysis faces challenges for large-scale commercial application due to its high electrical energy consumption, yet its immense potential warrants further in-depth investigation. Currently, a force-electrochemical coupling strategy employing external physical fields is emerging as a promising approach to assist both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). This work examines the HER and OER performances of a CuNi alloy electrocatalyst by applying surface acoustic waves (SAW) as an external physical field. The results demonstrate that SAW significantly enhances both HER and OER performances. For HER, the overpotential of the CuNi alloy at 10 mA cm^-2 was reduced by 29 mV under SAW, and the Tafel slope decreased from 115 to 101 mV dec^-1. For OER, the overpotential decreased from 430 to 390 mV, and the Tafel slope was notably reduced from 73.3 to 64 mV dec^-1. The performance enhancement is attributed to the accelerated adsorption of reactive hydrogen species during the HER and the optimized initial electron-transfer step in the OER induced by SAW. This optimization is likely mediated by SAW-induced interfacial lattice strain and the modulation of adsorption energetics for reaction intermediates.