Solar hydrogen production via water splitting is pivotal for solar energy harnessing, addressing key challenges in energy and environmental sustainability. However, two critical issues persist with single-component photocatalysts: suboptimal carrier transport and inadequate light absorption. While heterojunction-based artificial photosynthetic systems like Z-scheme photocatalysts have been explored, their charge recombination and light harvesting efficiency are still unsatisfactory. S-scheme heterojunctions have gained attention in photocatalysis, owing to their pronounced built-in electric field and superior redox capabilities. In this study, we introduce a MXene-based S-scheme H-TiO/g-CN/TiC heterojunction (TCMX), synthesized through electrostatic self-assembly. The as-prepared TCMX exhibited an excellent photocatalytic hydrogen evolution rate of 53.67 mmol g h surpassing the performance of commercial Rutile TiO, H-TiO, g-CN, and HTCN. The effectiveness of TCMX is largely due to the built-in electric field in the S-scheme heterojunction and the cocatalytic activity of MXene promoting rapid separation of photogenerated charges and resulting in well-separated electron and hole enriched sites. This study offers a new approach to enhance photocatalytic hydrogen evolution efficiency and paves the way for the future design of S-scheme heterojunctions.

中文翻译：

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采用 H-TiO2/g-C3N4 异质结与 MXene 结合的 S 型人工光合作用系统可促进太阳能氢气的释放


通过水分解生产太阳能氢气对于太阳能利用、解决能源和环境可持续性方面的关键挑战至关重要。然而，单组分光催化剂仍然存在两个关键问题：载流子传输不佳和光吸收不足。虽然Z型光催化剂等基于异质结的人工光合系统已经被探索，但它们的电荷重组和光捕获效率仍然不能令人满意。 S型异质结由于其明显的内置电场和优异的氧化还原能力而在光催化领域受到关注。在这项研究中，我们介绍了一种通过静电自组装合成的基于MXene的S型H-TiO/g-CN/TiC异质结（TCMX）。所制备的 TCMX 表现出优异的光催化析氢速率，为 53.67 mmol g h，超过了商业金红石 TiO、H-TiO、g-CN 和 HTCN 的性能。 TCMX 的有效性很大程度上归功于 S 型异质结中的内置电场和 MXene 的助催化活性，促进光生电荷的快速分离，并产生良好分离的电子和空穴富集位点。这项研究提供了一种提高光催化析氢效率的新方法，并为未来S型异质结的设计铺平了道路。