Rapid degradation of Rhodamine B using enhanced photocatalytic activity of MoS2 nanoflowers under concentrated sunlight irradiation

Abstract

The sustainable cost-effective wastewater treatment process is a global challenge. In this paper, we report a novel sustainable and cost-effective technique to clean wastewater using solar energy. We have observed a rapid degradation of Rhodamine B (RhB) dye photocatalised by MoS2 nanoflowers under concentrated sunlight irradiation. The concentrated sunlight has been delivered to the photocatalytic reactor using an optical fiber bundle coupled with a solar concentrator and the irradiance power of the used concentrated sunlight is 2.6 times higher than ordinary sunlight. The RhB dye is degradated by 39.9% and 67.4% respectively for ordinary and concentrated sunlight irradiation during 120 min. Therefore, degradation of RhB dye in concentrated sunlight is 1.7 times faster than ordinary sunlight. The well crystalline and uniform MoS2 nanoflowers have been prepared by simple hydrothermal method, which is cost-effective method to prepare nanomaterials in large scale. The optical band gap of the prepared MoS2 nanoflowers is 2.2 eV (564 nm), which makes MoS2 as most suitable photocatalysts under sunlight irradiation. This work will open new technological aspects for cost-effective sustainable wastewater treatment using sunlight.