Microflower-like NiFe layered double hydroxide @ g-C3N4 electrocatalysts for enhanced photo-assisted OER and overall water splitting performance

Abstract

Photo-assisted electrocatalysis has emerged as a cutting-edge area of electrocatalysis in recent times. It relies on the combined influence of electrical and optical energy, offering a novel approach to enhance electrocatalytic efficiency. In this study, we synthesized microflower-like catalysts consisting of NiFe layered double hydroxide and g-C3N4 (known as NiFe-LDH/CN@NF) directly on Ni foam using a one-step hydrothermal technique. Under the irradiation of 300W xenon lamp, the electrocatalytic activities of oxygen evolution reaction (OER) and overall water splitting of NiFe-LDH/CN@NF were significantly enhanced. Under photo-assisted circumstances, the OER overpotential (204mV@10mAcm−2) in KOH electrolyte is 23% lower than in dark conditions; the cell voltage of an electrolytic cell using NiFe-LDH/g-C3N4 as the cathode and anode decreased from 1.65V to 1.58V. According to study on mechanisms, the enhancement in OER can be mainly ascribed to the synergistic impact of photo-driven and electro-driven water oxidation processes. These results validate the broad generalizability of photo-assisted electrocatalysis technology and provide valuable insights into the advanced material design for sustainable energy conversion technologies.