Broad spectrum response flower spherical-like composites CQDs@CdIn2S4/CdS modified by CQDs with up-conversion property for photocatalytic degradation and water splitting

A composite material of CQDs@CdIn2S4/CdS modified by carbon quantum dots (CQDs) with up-conversion property was prepared by the microwave assisted method. CQDs@CdIn2S4/CdS composites consisting of hexagonal phase CdS and cubic phase CdIn2S4 show a uniform flower spherical-like morphology and a significant increase in specific surface area. Moreover, the prepared CQDs with up-converted photoluminescence property can convert long wavelength light (lambda > 600 nm) into short wavelength light (lambda < 600 nm), which can match the light absorption range of the composite CdIn2S4/CdS reasonably, broaden its light response range and improve its utilization of sunlight. At the same time, the photo catalytic activity of CQDs@CdIn2S4/CdS series composites under different light sources was studied with methyl orange as the model molecule, and 1% CQDs@CdIn2S4/CdS was determined as one of the best photocatalytic material. The composite material 1% CQDs@CdIn2S4/CdS not only had high photohydrogen production capacity (3177.8 mu mol/g, 8 h), but also had a very stable effect on the ultraviolet photocatalytic degradation rate and the final hydrogen evolution yield of photolyzed water after four cycles. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.