Three-dimensional ordered hollow sphere composite Pt/TiO2-ZrO2: enhanced performance of photocatalytic degradation and photocatalytic hydrogen evolution

In this paper, a three-dimensional ordered hollow sphere (3DOH) structure composite Pt/TiO2-ZrO2 was prepared by using polystyrene (PS) colloidal spheres as the template and combining with two-step vacuum impregnation method, of which the composition, crystalline structure, morphology, and surface physicochemical properties were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance (UV-vis/DRS), photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and nitrogen adsorption-desorption measurements. The results illustrate the crystal type of 3DOH Pt/TiO2-ZrO2 is mainly anatase TiO2 and tetragonal ZrO2 phase, which exhibits a three-dimensional ordered hollow sphere structure. Hollow spheres are arranged orderly; moreover, the composite shows a strong absorption in the visible region due to the effect of surface plasmon absorption (SPA) after doping Pt nanoparticles. Meanwhile, the photocatalytic activity of 3DOH Pt/TiO2-ZrO2 was investigated by using Congo red as the model molecule. The results show that 3DOH Pt/TiO2-ZrO2 has good photocatalytic activity under multi-modes photocatalytic experiments, and its activity is higher than that of P25, ZrO2, and other Pt/TiO2-ZrO2 not treated by PS colloidal spheres. In addition, the total amount of hydrogen production of 3DOH Pt/TiO2-ZrO2 is 100 times as much as the commercial P25 in the photocatalytic hydrogen evolution experiment (8 h), which shows an excellent photolysis of water hydrogen production activity.