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 [email protected]2S4/CdS modified by carbon quantum dots (CQDs) with up-conversion property was prepared by the microwave assisted method. [email protected]2S4/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 (λ > 600 nm) into short wavelength light (λ < 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 photocatalytic activity of [email protected]2S4/CdS series composites under different light sources was studied with methyl orange as the model molecule, and 1% [email protected]2S4/CdS was determined as one of the best photocatalytic material. The composite material 1% [email protected]2S4/CdS not only had high photohydrogen production capacity (3177.8 μmol/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.