Leveraging acoustic and mechanical wave phenomena to fabricate Cu(2-x)CoxP2O7 as electrocatalysts for energy storage and electrochemical water splitting application

Abstract

The development of renewable energy systems require the unification of efficient energy storage and hydrogen production facilities. Trifunctional electrocatalysts function as a single system which synchronously enables charge storage, hydrogen evolution reaction (HER), and oxygen evolution reaction (OER), providing a congruent platform. Systematic synthesis techniques promote the enhancement of catalytic activity, and long-term stability. In this context, low-frequency ultrasound (∼20 kHz) induces severe cavitation with the resultant physical forces generating radicals that primarily drive sonochemical processes. In this work, we employed a mechanical wave-assisted synthesis method to prepare Cu(2-x)CoxP2O7. The resulting electrocatalyst delivers an impressive specific capacitance of 681 F g−1, maintaining a cycling stability of 81% after enduring 30 000 cycles. The constructed symmetric supercapacitor attains an energy density of 17.4 Wh kg−1 and a power density of 699 W kg−1. Furthermore, CuCoP2O7 delivers strong bifunctional activity, necessitating merely 64 mV for HER and 288 mV for OER to reach a current density of 10 mA cm−2 while also facilitating overall water splitting by attaining 20 mA cm−2 at 1.60 V. Remarkably, the electrocatalyst achieves a Faradaic efficiency of 97.5%, demonstrating its outstanding effectiveness in facilitating oxygen and hydrogen evolution. These multifunctional electrocatalysts establish a pathway toward scalable, high-performance devices that integrate electrochemical energy storage with sustainable hydrogen production.