Catalysts | 卷:11 |
Controlled Synthesis of CuS and Cu9S5 and Their Application in the Photocatalytic Mineralization of Tetracycline | |
Opeyemi A. Oyewo1  Murendeni P. Ravele2  Damian C. Onwudiwe2  | |
[1] Department of Science and Technology Education, University of Johannesburg, Johannesburg 2092, South Africa; | |
[2] Material Science Innovation and Modelling (MaSIM) Research Focus Area, Faculty of Natural and Agricultural Sciences, Mafikeng Campus, North-West University, Private Bag X2046, Mmabatho 2735, South Africa; | |
关键词: CuS (covellite); Cu9S5 (digenite); tetracycline; photocatalysis; solvothermal synthesis; | |
DOI : 10.3390/catal11080899 | |
来源: DOAJ |
【 摘 要 】
Pure-phase Cu2−xS (x = 1, 0.2) nanoparticles have been synthesized by the thermal decomposition of copper(II) dithiocarbamate as a single-source precursor in oleylamine as a capping agent. The compositions of the Cu2−xS nanocrystals varied from CuS (covellite) through the mixture of phases (CuS and Cu7.2S4) to Cu9S5 (digenite) by simply varying the temperature of synthesis. The crystallinity and morphology of the copper sulfides were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), which showed pure phases at low (120 °C) and high (220 °C) temperatures and a mixture of phases at intermediate temperatures (150 and 180 °C). Covellite was of a spherical morphology, while digenite was rod shaped. The optical properties of these nanocrystals were characterized by UV−vis–NIR and photoluminescence spectroscopies. Both samples had very similar absorption spectra but distinguishable fluorescence properties and exhibited a blue shift in their band gap energies compared to bulk Cu2−xS. The pure phases were used as catalysts for the photocatalytic degradation of tetracycline (TC) under visible-light irradiation. The results demonstrated that the photocatalytic activity of the digenite phase exhibited higher catalytic degradation of 98.5% compared to the covellite phase, which showed 88% degradation within the 120 min reaction time using 80 mg of the catalysts. The higher degradation efficiency achieved with the digenite phase was attributed to its higher absorption of the visible light compared to covellite.
【 授权许可】
Unknown