NiFe layered double-hydroxide nanoparticles for efficiently enhancing performance of BiVO4 photoanode in photoelectrochemical water splitting

A bismuth vanadate (BiVO4) photoanode with a cocatalyst consisting of NiFe layered double-hydroxide (NiFe-LDH) nanoparticles was fabricated for photoelectrochemical (PEC) water splitting. NiFe-LDH nanoparticles, which can improve light-absorption capacities and facilitate efficient hole transfer to the surface, were deposited on the surface of the BiVO4 photoanode by a hydrothermal method. All the samples were characterized using X-ray diffraction, scanning electron microscopy, and diffuse-reflectance spectroscopy. Linear sweep voltammetry and current-time plots were used to investigate the PEC activity. The photocurrent response of NiFe-LDH/BiVO4 at 1.23 V vs the reversible hydrogen electrode was higher than those of Ni(OH)2/BiVO4, Fe(OH)2/BiVO4 and pure BiVO4 electrodes under visible-light illumination. NiFe-LDH/BiVO4 also gave a superior PEC hydrogen evolution performance. Furthermore, the stability of the NiFe-LDH/BiVO4 photoanode was excellent compared with that of the bare BiVO4 photoanode, and offers a novel method for solar-assisted water splitting.