Das Sankar, Ng Li Shiuan, Pereira Veronica, Zhang Jiajia, Ahn Young-Ho, Lee Hiang Kwee
Division of Chemistry and Biological Chemistry, School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
Department of Civil Engineering, Yeungnam University, Gyeongsan, 38541, South Korea.
Small. 2025 Jul;21(26):e2501572. doi: 10.1002/smll.202501572. Epub 2025 May 16.
Photocatalytic water splitting offers a sustainable pathway for producing clean H fuel. However, conventional heterojunction photocatalysts face severe challenges, including diminished redox potential due to complex band alignments, interfacial defects accelerating charge recombination, and long charge-carrier paths reducing photocarrier and material utilization. Here, we achieve efficient, visible-light-driven H generation by employing a dilute bimetallic dispersion on a metal chalcogenide nano-photocatalyst. Using CdS nanorod as a model photocatalyst, we strategically position Cu in lattice sites and Co in interstitial locations to preserve CdS's strong optical properties and redox potential. In this design, Cu species serve as electron sinks to drive H evolution, while the Co/Co couple functions as a redox shuttle to efficiently channel photogenerated holes to the reactant. This optimized photocatalyst demonstrates a high H production rate of ≈52 mmol g h, surpassing bare CdS and other emerging photocatalytic designs by >100-fold and >65-fold, respectively. Mechanistic studies highlight the roles of Cu and Co as electron and hole sinks and active redox sites, thereby facilitating directed photocarrier migration and enhanced light-to-chemical conversion. By establishing spatially distinct redox sites, this work provides a foundational framework for designing next-generation photocatalytic platforms, paving the way for sustainable energy and chemical applications using light.
光催化水分解为生产清洁氢燃料提供了一条可持续的途径。然而，传统的异质结光催化剂面临着严峻的挑战，包括由于复杂的能带排列导致氧化还原电位降低、界面缺陷加速电荷复合以及长的电荷载流子路径降低了光载流子和材料利用率。在此，我们通过在金属硫族化物纳米光催化剂上采用稀双金属分散体实现了高效的可见光驱动产氢。以硫化镉纳米棒作为模型光催化剂，我们将铜战略性地置于晶格位置，将钴置于间隙位置，以保留硫化镉的强光学性质和氧化还原电位。在这种设计中，铜物种作为电子阱来驱动析氢，而钴/钴电对作为氧化还原穿梭体，将光生空穴有效地输送到反应物中。这种优化后的光催化剂展示出约52 mmol g⁻¹ h⁻¹的高产氢速率，分别比裸硫化镉和其他新兴光催化设计高出100倍以上和65倍以上。机理研究突出了铜和钴作为电子和空穴阱以及活性氧化还原位点的作用，从而促进了定向光载流子迁移并增强了光到化学的转化。通过建立空间上不同的氧化还原位点，这项工作为设计下一代光催化平台提供了一个基础框架，为利用光的可持续能源和化学应用铺平了道路。
