Catalytic decomposition of Bismarck brown by nanostructured CuS in mild conditions

Abstract

Two samples of nanostructured CuS were synthesized by two different methods, and were used for degradation of Bismarck Brown, as an azo dye. The first sample consists an assembly of nanosheets, and the second one has prolat-like spheroid structure. It is shown that CuS nanosheets have higher catalytic activity than the second sample for degradation of Bismarck Brown in the presence of H2O2. The catalytic activity of the CuS nanosheets was investigated by different variables such as reaction time, solution temperature, volume of H2O2, catalyst mass, dye concentration and presence of NaCl. CuS nanosheets have high degradation efficiency under mild conditions and in the dark medium. It was found that the rate of dye degradation by H2O2 is fast in the presence of CuS nanosheets, and most of the reactant molecules are degraded within 10 minute. As the main products of dye degradation by the CuS nanosheet, and in presence of H2O2 are CO2 and CO, it is a good catalyst for water purification. Another advantage of this catalyst is its reusability and recyclability, which maintains its stability after several cycles. Finally, the catalytic performance of CuS nanosheets was investigated for degradation of dye mixture (Bismarck Brown and Methyl violet).