Degenerated TiO2 Semiconductor Modified with Ni and Zn as Efficient Photocatalysts for the Water Splitting Reaction

Abstract

AbstractThe development of robust, safe, cost‐effective and efficient photocatalytic systems for water splitting should take into account the presence of a proper and powerful photon absorber and an efficient, low‐cost and earth‐abundant electrocatalyst to perform the reaction at high conversions. In this study, Ni−Zn/TiO2 ternary composites with high photocatalytic activity for water splitting under UV irradiation were successfully prepared via a simple and low‐cost deposition‐precipitation route. Thus, different Ni : Zn molar ratios (1 : 0, 1 : 1, 3 : 1, 6 : 1, 9 : 1, and 0 : 1) were deposited on TiO2 in order to reach a total metal loading of 50 wt. %. The obtained composites were characterized using several techniques, such as: X‐ray diffraction, UV‐Vis spectroscopy, X‐ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The most active synthesized composite, namely Ni−Zn/TiO2 (9 : 1), exhibits H2 generation rate above 17 mmols g−1 h−1, which is nearly one thousand times higher than that obtained with TiO2 Evonik P25. Our study demonstrates that TiO2 becomes a degenerated semiconductor in the presence of Ni and ZnO, with remarkable photocatalytic properties. Thus, the obtained results can open new opportunities in the preparation of very active materials for hydrogen production based on the optimization of three‐component structures.