Preparation And Photocatalytic Properties Of Copper And Silver Supported Titanium Dioxide Nanoblocks

Recent years, environmental problems related to organic pollutants and shortage of energy have attracted widespread attention at home and abroad. In order to solve these problems, photocatalysis, as a kind of green energy conservation and environmental protection technology has attracted wide attention of scholars in the fields of physics, chemistry, materials. TiO2 photocatalytic technology as a kind of green technology, can relieve the energy crisis, reduce environmental pollution, has been widely applied in photocatalytic water splitting to generate hydrogen, photocatalytic reduction of carbon dioxide, sewage treatment, air purification and sterilization, etc. However, TiO2 has a relatively wide band that requires ultraviolet (UV) light for activation, besides, TiO2 has a high recombination rate of electron-hole pairs during the photocatalysis process, leading to a lower photocatalytic efficiency. This paper we combined the structure of TiO2 and metal ions doping, aming to promote TiO2 photocatalytic water splitting to generate hydrogen, so we carried out the following research content.The paper used a strategic hydrothermal synthesis of TiO2 nanoflowers and TiO2 nanoballs with well-defined shape and size. Then the nanoparticles of Cu and Ag were loaded on the surface of TiO2 NFs besides Ag nanoparticles loaded on TiO2 NBs to obtain (Cu/TiO2 NBs)、(Ag/TiO2 NFs) and (Ag/TiO2 NBs) photocatalysts. The as-prepared composite was characterized by, X-ray diffraction (XRD), photoluminescence spectrum (PL), scanning electron microscope (SEM), UV-vis absorption spectrum (UV-vis),and Raman spectrum(Raman), respectively, to explore its overall appearance characteristics, reflected by the surface of the crystal structure and spectral properties, reveals the relationship between the catalytic activity and its structure. The SEM results shows that TiO2 nanoflowers assembled with ordered nanorods and the nanoball was composed of nanoparticles, the diameter was 1μm and 4μm, respectively, its unique three-dimensional structure improve the performance of light. XRD analysis found that TiO2 particles was rutile phase structure, the characteristics of diffraction peak was 20=27.5°. PL analysis found that the presence of Cu and Ag particles makes TiO2 fluorescence quenching occurs, located at 400 nm (3.18 eV) and 475 nm (2.67 eV) emission peak intensity is decreased obviously. With the increasing of density of Ag and Cu, Raman scattering were enhanced, at the same time the visible light absorption intensity was enhanced, this may be related to surface plasmon resonance effect. This paper examines the Ag and Cu load on the photocatalytic properties of TiO2,two kinds of Ag/TiO2 nano materials were applied into the experiment of photocatalytic water splitting. The results indicated that, when the concentration of Ag/TiO2 is 0.05mol/L, the hydrogen production rate of Ag/TiO2 NFs was 3.9 times higher than pure TiO2 nanoflowers, the hydrogen production rate of Cu/TiO2 NFs was 2.4 times higher than pure TiO2. The hydrogen production rate of Ag/TiO2 NBs was 1.7 times higher than pure TiO2.In the end the mechanism of photoreaction evolved with surface plasmon resonance effect was proposed.