Low-cost synthesis of titanium dioxide anatase nanoclusters as advanced materials for hydrogen photoproduction

Sub-nm titanium dioxide (TiO2) clusters are synthesized via the hydrolysis of TiCl4 in order to produce clean and surfactant-free oxide surfaces. By controlling the synthesis, stable TiO2 nanoclusters with well-defined size distributions are obtained. The prepared clusters are characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Raman spectroscopy in order to gain information about the size and morphology of the material. Photoresponsive methylene blue dye monitoring and hydrogen production under UV irradiation are described in detail and performed. The rate order of photodegradation and hydrogen photoproduction under UV light irradiation of the samples is increased by decreasing the size of TiO2 nanoparticles from 47 nm to 3 nm. The hydrogen evolution rate of TiO2 nanoclusters with size lower than 5 nm is about 3.03 times and 1.96 times faster than that of 47 nm of TiO2 and 12 nm of TiO2, respectively. The enhanced photocatalytic performance suggests that the ternary TiO2 nanoclusters can serve as a highly efficient catalyst for photodegradation of organic pollutants in aquatic environments and hydrogen production from water splitting.