Enhanced Photocatalytic Hydrogen Generation via Up-conversion in Y2O3:Yb3+, Er3+ Nanoparticles Under Near-infrared Light Irradiation

Against the backdrop of increasing energy shortages, hydrogen energy has garnered significant attention as a green and clean alternative energy source. To fully exploit a broader portion of the solar spectrum, we designed a Y 2 O 3 :Yb 3+ , Er 3+ /ZnIn 2 S 4 (denoted as YYE/ZIS) composite photocatalyst with a well-defined loaded structure of coating Y 2 O 3 :Yb 3+ , Er 3+ nanoparticles on the ZnIn2S4 micro-flowers, capable of efficiently utilizing near-infrared (NIR) light through an up-conversion mechanism. The introduction of Yb 3+ and Er 3+ ions endows the Y 2 O 3 with excellent up-conversion luminescence properties, enabling the effective conversion of lowenergy NIR photons into high-energy visible light over YYE/ZIS composite, which subsequently activates the ZIS component for NIR-driven photocatalytic hydrogen production. Photoelectrochemical characterizations reveal that the loaded structure significantly facilitates efficient charge separation and migration at the interface, while markedly suppressing the recombination of photogenerated electron-hole pairs, thereby enhancing the overall photocatalytic performance. Remarkably, the catalyst demonstrates excellent NIR-response hydrogen evolution performance (16.3 μmol·g -1 ·h -1 ) even in the absence of noble metal co-catalysts, such as Pt, achieving a hydrogen production rate approximately 10.9 times higher than that of pristine ZIS. This work proposes a novel approach for constructing up-conversion-enabled composite photocatalysts with rationally engineered interfacial architectures.