Multifunctional photo-electrocatalysts of copper sulfides prepared via pulsed laser ablation in liquid: Phase formation kinetics and photo-electrocatalytic activity

Designing a highly efficient and less expensive electrocatalyst for electrolyzers and fuel cells is of great importance to creating a sustainable future energy source. Herein, we applied a unique and extremely facile pulsed laser ablation in the liquid synthesis route for the fabrication of phase-engineered CuxSy nanospheres. The multifunctionality of these catalysts was assessed by examining the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and methanol oxidation reaction (MOR). As a result, low overpotentials of 390 mV (HER) and 440 mV (OER) were achieved for sulfur-rich and copper-rich samples in alkaline media, respectively. Furthermore, the high selectivity of Cu over methanol and the high number of electrochemically accessible active sites equal to 7.9 x 10(16) promoted the MOR with a current density of 28.3 mA/cm(2) at the vertex potential. It is worth emphasizing that in this research, we consider the electrocatalyst's initial electrocatalytic water decomposition function to gain a better understanding of the photoelectrocatalytic behavior. Using a beneficial photo-assisted electrochemical method, a high OER catalytic activity was obtained under light irradiation due to the large light absorption coefficients of the synthesized electrocatalysts, which facilitated electron transfer at the electrode-electrolyte interface.

Automated summary

Designing efficient and cost-effective electrocatalysts is crucial for creating a sustainable future energy source. In this study, phase-engineered nanospheres were synthesized using a unique liquid-based pulsed laser ablation method, and their multifunctionality was evaluated in hydrogen evolution, oxygen evolution, and methanol oxidation reactions. The synthesized electrocatalysts exhibited low overpotentials and high activity in alkaline media.