S-doped HTiNbO5 nanosheets: A novel efficient visible-light photocatalyst

S-doped HTiNbO5 nanosheets were prepared via an exfoliation-flocculation-calcination process using layered HTiNbO5 as the starting material and thiourea as the S source. The resulting catalyst had higher surface area and visible-light absorption than did unexfoliated HTiNbO5 or HTiNbOs nanosheets. The adsorption and photodegradation of rhodamine B were evaluated under visible-light irradiation on the obtained catalysts. Both HTiNbO5 nanosheets and S-doped HTiNbOs nanosheets showed enhanced adsorption capacity and a high visible-light photodegradation rate. However, a much higher degree of mineralization (41%) was achieved using the S-doped HTiNbO5 nanosheets, compared with almost no mineralization for the HTiNbOs nanosheets, indicating that S doping can effectively improve the photocatalytic activity of nanosheets. The possible photodegradation mechanisms are also discussed. (C) 2013, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.