CuS-Cu9S8 nanoparticles as an efficient catalyst: A facile method via anion controlled

In this paper, a facile, surfactant-free and mild solution chemistry route was employed to prepare copper sulfide (CuS-Cu9S8) nanoparticles (NPs) by using anion-controlled agents with a different electronegativity. Counterions CH(3)COO( )(-)were found to be suitable for regular hexagonal morphology formation, whereas in the presence of NO3- irregular structure is obtained. By changing the anion of the copper precursor, the ratio of formation of Cu9S8 and CuS can be changed, and the band gap energy (Eg) of asprepared NPs can be controlled in the presence of anion-controlled agents. Moreover, we demonstrate here the catalytic performance of the as-prepared samples for the degradation of methylene blue (MB) both under the simulated natural light and in dark, and the result shows that the CuS-Cu9S8 NPs exhibited better catalytic activity under visible light (> 50%) than in darkness (45%), and CuS-Cu9S8 NPs with higher electronegativity of anion-controlled exhibited the higher catalytic performance. In addition, a simple and direct diagram was applied to illustrate the mechanism of the degradation of MB.