棒状CoSx/TiOx@ZIS核-壳双S-scheme异质结用于太阳能驱动水解制氢与光热转换

Rod-shaped CoSx/TiOx@ZIS core-Shell dual S-scheme heterojunctions for solar-driven water splitting to produce hydrogen and photothermal conversion

  • 摘要: 开发能够促进电子迁移并提升氧化还原反应性能的高效光催化剂,是实现光催化分解水制氢的重要途径。本研究采用油浴-高温硫化法成功构建了棒状CoSx/TiOx@ZnIn2S4(CoSx/TiOx@ZIS)核-壳双S-scheme异质结,CoSx和TiOx纳米颗粒的随机分布确保了紧密接触,提高了界面传输的畅通性和光电子-空穴对的有效分离。超薄ZnIn2S4纳米片紧密地包覆于CoSx/TiOx纳米棒表面,构建双内置电场进一步提高了光生载流子分离率。同时,CoSx的光热效应在局部形成高温环境,显著提升了反应动力学。光催化性能测试表明,优化后的催化剂产氢速率达到~42.947 mmol·g−1·h−1,分别为纯CoSx/TiOx和ZnIn2S4的~203.5倍和~8.3倍,该性能的提升归因于S型异质结的协同效应、增强的光吸收能力以及光热效应。CoSx/TiOx@ZIS在0.3 W·cm−2的照射下,光热转换效率达到~60.30%,是纯ZIS的~1.3倍。在380 nm处,其表观量子效率(AQE)高达~49.8%,显著优于已报道的大多同类光催化剂。此外,连续4次循环测试后其催化性能衰减率低于~7.9%,表现出良好的稳定性。本研究结果表明,双S-scheme异质结结构可促进空间电荷的有效分离与光能利用,强化光热协同催化性能。

     

    Abstract: Developing efficient photocatalysts capable of promoting electron transfer and enhancing redox reaction performance is a crucial approach to achieve photocatalytic water splitting for hydrogen production. In this study, a rod-shaped CoSx/TiOx@ZnIn2S4 (CoSx/TiOx@ZIS) core-shell dual S-scheme heterojunction was successfully constructed using an oil bath-high temperature sulfiding method. The random distribution of CoSx and TiOx nanoparticles ensured intimate contact, improving the smoothness of interfacial transfer and the effective separation of photoelectron-hole pairs. The ultrathin ZnIn2S4 nanosheets were tightly coated on the surface of CoSx/TiOx nanorods, constructing a dual built-in electric field to further enhance the separation rate of photogenerated carriers. Simultaneously, the photothermal effect of CoSx created a high-temperature environment locally, significantly enhancing the reaction kinetics. Photocatalytic performance tests revealed that the optimized catalyst achieved a hydrogen production rate of ~42.947 mmol g−1·h−1, which was ~203.5 times and ~8.3 times higher than that of pure CoSx/TiOx and ZnIn2S4, respectively. This performance enhancement was attributed to the synergistic effect of the S-scheme heterojunction, enhanced light absorption capability, and photothermal effect. Under an irradiation of 0.3 W·cm−2, the photothermal conversion efficiency of CoSx/TiOx@ZIS reached 60.30%, which is ~1.3 times higher than that of pure ZIS. At 380 nm, its apparent quantum efficiency(AQE) reached ~49.8%, significantly outperforming most reported similar photocatalysts. Furthermore, after four consecutive cycles of testing, the degradation rate of its catalytic performance was less than ~7.9%, demonstrating excellent stability. The results of this study indicate that the dual S-scheme heterojunction structure promotes effective separation of spatial charges and utilization of light energy, enhancing the synergistic photocatalytic performance of photothermal catalysis.

     

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