Optical properties of Cu-incorporated ZnO (CuxZnyO) nanoparticles and their photocatalytic hydrogen production performances

In this work, the Cu (0.1, 0.5, 1.0, and 5.0 mol.-%)-incorporated ZnO nanoparticles (CuxZnyO) are prepared by a conventional hydrothermal method. Powder X-ray diffraction patterns confirm that Cu ion is stably inserted into the framework of ZnO, and the crystallite size decreases as the amount of Cu ion increases. With the insertion of Cu ions into ZnO, the recombination rate of photogenerated charge carriers is found to be low which in turn increases the photocatalytic activity. The H2 production activity of Cu-inserted ZnO catalysts is higher than the pure ZnO catalyst. Among the different samples, the Cu0.01Zn0.99O catalyst having a 1.0 mol.-% of Cu shows the higher H2 production activity. The enahanced H2 production activity of CuxZnyO catalysts is attributed to the longer life-time of excited electrons during the photocatalytic reaction and the decreased electron-hole recombination rate. [Display omitted] •Preparation of CuxZnyO nanoparticle using a conventional hydrothermal method.•Stronger photocurrent on CuxZnyO than on pure ZnO.•Longer lifetime of electron on CuxZnyO than on pure ZnO.