Photodeposition-assisted synthesis of novel nanoparticulate In,S-codoped TiO_2 powders with high visible light-driven photocatalytic activity

摘要

In order to search for an efficient photocatalysts working under visible light illumination, we have investigated the effect of metal and nonmetal ions (In, S) codoping on the photocatalytic activity of TiO_2 nanopartides (TiO_2 NPs) prepared by combining of sol-gel (SG) and photodeposition (PD) methods using titanium tetra isopropoxide (TTIP), indium nitrate (In(NO_3)_3) and thiourea as precursors. In this regard, at first three different percentage of S (0.05,0.2 and 0.5) doped into the TiO_2 by SG method, and then different amount of In(Ⅲ) loaded on the surface of the prepared samples by PD technique. The results showed that the In, S-codoped TiO_2 (In, S-TiO_2) with a spheroidal shape demonstrates a smaller grain size than the pure TiO_2. Meanwhile, the UV-vis DRS of In, S-TiO_2 showed a considerable red shift to the visible region. Finally, the photocatalytic activity of In, S-TiO_2 photocatalysts were evaluated by photooxidative degradation of methyl orange (MO) solution under UV and visible light illumination. As a result, it was found that 0.05%S-0.5%In/TiO_2,0.2%S-l .5%In/TiO_2 and 0.5%S-0.5%In/TiO_2 had the highest catalytic activity under visible light in each group and among these samples 0.2%S-1.5%In/TiO_2 showed the best photocatalytic performance under visible light and decomposes more than 95% MO in only 90 min.