Enhancing Electrocatalytic Water Splitting Activities\nvia Photothermal Effect over Bifunctional Nickel/Reduced Graphene\nOxide Nanosheets

Abstract

Electrocatalytic\nwater splitting has huge potential for generating\nhydrogen fuel. Its wide application suffers from high energy loss\nand sluggish reaction kinetics. The adoption of appropriate electrocatalysts\nis capable of reducing the overpotential and accelerating the reaction.\nPresent research mainly focuses on adjusting electrocatalysts, but\nthe performances are also dependent on other parameters. Therefore,\nthe development of an efficient strategy to enhance electrocatalytic\nperformance through integrating with other driving force, especially\na renewable driving force, is of great interest. Herein, we present\na photothermal-effect-driven strategy to promote the electrocatalytic\nhydrogen evolution reaction (HER) and oxygen evolution reaction (OER)\nactivities of nickel/reduced graphene oxide (denoted as Ni/RGO) bifunctional\nelectrocatalysts. The Ni/RGO composite exhibited significant enhancement\nof activities after exposure to light irradiation (49 mV and 50 mV\ndecrease of overpotential at 10 mA/cm² for HER and OER,\nrespectively). It was found that the improved electrocatalytic activities\narose from the photothermal effect of Ni/RGO, which can efficiently\nfacilitate the thermodynamics and kinetics of electrocatalytic reactions.\nFurthermore, the photothermal-effect-induced enhancement for electrocatalysis\nshowed good stability, indicating its promising potential in practical\napplication.