Photocatalytic activities of Sr₂Ta₂O₇ nanosheets synthesized by a hydrothermal method

Sr₂Ta₂O₇ nanosheets have been synthesized by a hydrothermal method without using any template. The thickness, widths, and lengths of Sr₂Ta₂O₇ nanosheets are about 10-50 nm, 50-150 nm, and 500 nm, respectively. The optimum conditions for the formation of the nanosheets are maintaining the reactants at 260 °C for 7 days. On basis of the experimental data, a possible formation mechanism of the nanosheets under the hydrothermal conditions was proposed. The photocatalytic activity for water splitting was investigated under ultraviolet irradiation. It has been found that Sr₂Ta₂O₇ nanosheets, compared to the bulk Sr₂Ta₂O₇ sample, showed a higher photocatalytic activity even in the absence of a cocatalyst. The higher activity of the hydrothermally synthesized sample is attributed to its larger surface areas and nanoscale structure.