Optical properties and anti-microbial activities of chalcopyrite/wurtzite CuInS<inf>2</inf> nanostructures synthesized via cyclic microwave irradiation

Abstract

CuInS2 nanostructures were successfully synthesized by a cyclic microwave irradiation method at 600 W without adding any activated solvents or capping reagents. The pure CuInS2 with the chalcopyrite and wurtzite crystal structures were obtained with the prolonged irradiation time as 30 and 75 cycles, respectively. The chalcopyrite CuInS2 powders were nanoparticles with diameter of about 20–40 nm, and the wurtzite CuInS2 powders were hexagonal plates with diameter of about 300–400 nm that preferentially grow along the <011¯0> directions. The optical properties of the synthesized CuInS2 observed by UV–vis DRS spectra show their direct band gap energy of 1.48 eV. The anti-microbial activities of the synthesized CuInS2 were investigated.