Efficient hydrogen production by water-splitting over Pt-deposited C–HS–TiO2 hollow spheres under visible light

Abstract

A Pt-deposited C–HS–TiO2 hollow sphere prepared through a simple template approach as well as their implementation as a photocatalyst for water splitting. The obtained Pt-deposited C–HS–TiO2 hollow spheres are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), UV–vis absorption spectrum (UV–vis), and transmission electron microscope (TEM). The results show that hollow spherical morphology was successfully synthesized. Compared with commercial P-25 TiO2 and C–TiO2 hollow sphere, Pt-deposited C–HS–TiO2 hollow spheres exhibit significant improvement in photoactivity under the visible light irradiation. It can be attributed to the enhanced visible light absorption by the deposited Pt. Furthermore, 1.0 wt% Pt/C–HS–TiO2 presents an ultra-high photocatalytic water splitting activity. The maximum production rate of hydrogen at a reaction temperature of 25 °C is measured as 2857 µmol/h. In addition, 1.0 wt% Pt/C–HS–TiO2 exhibits excellent long-term stability and durability of photocatalytic activity. The rate of visible light water splitting has no significant change. After 22 days of operation, an 8% loss of the initial activity occurs. Finally, the probable mechanism of hydrogen production by water splitting under visible light irradiation is proposed in this study.