光热-催化效应耦合的太阳能分解水制氢反应界面热电子传递强化研究

Solar photocatalytic water splitting for hydrogen generation provides an ideal alternative for clean energy supply and fossil fuel substitution, while the core objective of the research is to enhance the efficiency of solar to hydrogen (STH) conversion drastically. In photocatalytic procedure, the hot electrons are the key microscopic medium for energy transfer and conversion. The study on transport and interfacial behavior of hot electron would concern the full process resistance reduction of STH, which is of great significance for accelerating STH conversion. Under the support of the former NSFC Youth Fund presided over by the applicant, controllable semiconductor-metal heterointerface was successfully constructed to enhance the separation of hot electron from semiconductor to metal. As a consequence, a STH conversion efficiency of 6.6% is obtained, which is the highest reported. Based on all above, this project proposes a strategy to further improve the hydrogen production rate, that is to say, the IB-VIII bimetal interface structure will be controllably fabricated on the semiconductor surface, so that the hot electron energy gathered in the VIII metal can be increased by plasma photothermal effect of IB group metal. By the morphology, size and distribution control of bimetallic particle as well as the physicochemical properties characterization, we expect to reveal the influencing mechanism of photothermal excitation on the hot electron transfer, to develop the enhancing method of hot electrons transfer on the surface of metal particles, and next to put forward the strengthening theory of hot electron transfer coupled with photothermal-catalytic effect, and finally to construct a micro-multiphase reaction interface with high efficiency and low resistance. This system is anticipated with a further elevated solar to hydrogen conversion efficiency. As a result, new approach and theoretical support for the industrialization of the technology will be provided by the project.

太阳能光催化分解水制氢为人类的清洁能源供给和化石燃料的替代提供了理想选择，大幅度提高光氢转化效率是研究的核心目标。该过程中能量输运的关键微观媒介是热电子，其传输及界面行为的研究关系到光到氢的全流程减阻，对加速光氢转化至关重要。申请人前期主持的青年基金主要通过构筑可控半导体-金属异质界面，强化热电子从半导体到金属的分离聚集，获6.6%的光氢转化效率，为国际同类报道最高值。基于此，本项目提出进一步在半导体表面可控构筑IB-VIII族双金属界面结构的思路，以IB族等离子光热效应提高聚集于VIII族金属内的热电子能势，提高制氢速率。通过双金属颗粒的形貌、粒径和分布调控及性能表征，以期揭示光热激发对热电子传输的影响机制，发展热电子在金属颗粒表面传递的强化方法，形成光热-催化效应耦合的热电子传输强化理论，构建高效低阻的微观多相反应界面，实现光氢转化效率的再提高，为该技术工业化提供新的途径和理论支持。

本项目构建了一系列具有光热效应的高效复合光催化剂，以微观固液界面处能量及反应介质的传输转化为研究对象，通过水相种子生长法及催化剂表面可控磷化方法，实现了IB-VIII双金属纳米颗粒在Cd1-xZnxS纳米孪晶同质结及g-C3N4纳米片表面的可控沉积，揭示了光热激发对热电子传输的影响机制，发展了热电子在金属颗粒表面传递的强化方法，形成光热-催化效应耦合的热电子传输强化理论，构建了高效低阻的微观多相反应界面，实现了光氢转化效的再提高。在此基础上，进一步建立了连续可调的聚光光催化反应系统，将光热耦合效应与高效光热催化材料结合，发展了太阳能在液-固/气-固解耦型光催化反应体系中的高效传输和转化理论，实现光催化界面反应与气体产物脱附的时空解耦，加快表面能质传输过程。围绕项目研究内容，共发表 SCI 第一及通讯作者论文 20 篇，申请发明专利 5 项，参与制定国家标准一项，参与撰写英文专著一部，培养硕士、博士研究生共 8 名。项目研究期间获荣誉奖励有“长江学者奖励计划青年学者”、“2020年陕西省自然科学优秀学术论文一等奖”、“霍英东青年教师基金”和“2022年中国可再生能源学会科学技术一等奖”。