Effects of Ce Doping on the Photocatalytic and Electrochemical Performance of Nickel Hydroxide Nanostructures

Ni(OH)2 doped with cerium cations was synthesized by a hydrothermal method and its electrochemical, photoelectrochemical and photocatalytic behavior was determined by the corresponding suitable techniques. Ni(OH)2 films doped with different Ce proportions were evaluated in a KOH support electrolyte solution by cyclic voltammetry. Scan-rate dependent voltammograms displayed pseudo-capacitive behavior while the charge transfer resistance of Ce-doped samples was determined through electrochemical impedance spectroscopy. The calculated charge transfer resistance value was 132 Ω for Ni(OH)2 containing 350 μmoles of Ce. Chronoamperometry under intermittent UV light was employed to measure the photo-response of nanomaterials. The experimental results indicated that the photocurrent of Ni(OH)2 containing 350 µmoles of Ce was ten times greater than that of pure Ni(OH)2. Photocatalytic activity of the powders was demonstrated under UV light irradiation accomplishing 83% of methyl orange degradation after 140 min of reaction with pseudo-first-order kinetics and the calculated degradation rate constant was 0.0125 min− 1. The results evidenced the electrochemical, photoelectrochemical and photocatalytic activity of the synthesized materials, which sets them as suitable materials for a wide range of promising photo-based applications.