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Moreover, the photogenerated electrons can reduce Cr(VI) under sunlight or simulated sunlight irradiation. Semiconductor materials have their unique electronic band structure, which will produce highly reactive electrons and holes when the electron of the valence band transits to the conduction band inspired by the light of appropriate wavelength. Heterogeneous photocatalytic techniques based on semiconductor materials are widely used in photocatalytic decomposition of water, CO 2 reduction, and organic reactions. The photocatalytic technology driven by solar light has become more and more attractive because solar energy is one of the most abundant resources. An alternative strategy is provided in this study for fabrication of UCNP/semiconductor composites for various applications.
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All these can be attributed to the enhanced crystallization degree, resulting in enhanced energy transfer efficiency and separation efficiency of the photogenerated electrons and holes. Moreover, the 0.5Cd 0.5S yolk-shell nanoparticles (YSN) have been obtained from the 0.5Cd 0.5S CSN after calcination at 400☌, which show significantly photocatalytic activity for reduction of Cr(VI) under near-infrared light. Firstly, a layer of AA-Zn(Cd) 4− composites was coated on UCNPs to form 4− composites, which has been converted to 0.5Cd 0.5S CSN via sulfidation reaction process using thioacetamide (TAA) as the sulfur source. In this work, we have demonstrated a two-step solution process to synthesize 0.5Cd 0.5S core-shell nanoparticles (CSN). Constructing near-infrared-light-mediated core-shell nanostructures incorporating upconversion nanoparticles (UCNPs) and semiconductors is of great importance for potential applications in photocatalysis, nano-biomedical engineering, solar cell, etc.