Nickel oxide on mechanochemically synthesized TiO<inf>2</inf>–CeO<inf>2</inf>: photocatalytic and electrochemical activity

Abstract

This paper presents a new two-step method for the synthesis of NiO/TiO2–CeO2 semiconductors, which implies, the first, the mechanochemical synthesis of TiO2–CeO2 support, and the second is the doping of different NiO contents by chemical precipitation in an aqueous medium in an ambient atmosphere. Structural, optical, electrochemical and photocatalytic properties of NiO/TiO2–CeO2 semiconductors were examined. The influence of different NiO contents on the electrocatalytic activity of NiO/TiO2–CeO2 samples was investigated in the oxygen evolution reaction and the results showed that the samples with the lowest NiO content have the highest electroactivity. The photocatalytic activity was determined during the phenol decomposition process over the samples with different NiO:TiO2–CeO2 ratios and the best photocatalytic activity is observed for the sample with 4.1 mol% NiO. The sample with the lowest NiO content obtained by a relatively simple method is suitable for use both as an electrode material in the oxygen evolution reaction and as a photocatalyst in the phenol decomposition process.