钙钛矿NaTaO3纳米晶表界面结构调控及光解水制氢性能研究

As a clean and low-carbon energy preparation technology, photocatalytic water splitting for hydrogen production has great application prospects. The develop of highly efficient photocatalyst is the key to overcome the drawback of low quantum efficiency of the photocatalyst and promote this technology to industrialization. For the good plasticity, perovskite NaTaO3 nanocrystals probably become the one of the best photocatalysts for water splitting by modification. However, the internal structure is complicated and the Ta-O bond is hard to break, which result in the difficult control of the surface and interface structure of NaTaO3 nanocrystals with UV photo-response. It has been being significant scientific problems on the modification research of NaTaO3 nanocrystals that how to improve the performance of photocatalytic water splitting and the utilization efficiency of visible light through the control of the surface and interface structure. In this project, NaTaO3 nanocrystals with high energy surfaces exposure in a high percentage and different crystal surfaces coexistence will be synthesized through the control of synthesis parameters. On this basis, noble metals and semiconductors with narrow band gap will be selectively deposited on the specific surfaces by light irradiation to construct heterostructures. For the synergistic effect of surface and interface structures, it will broaden the spectrum response range of the photocatalysts, and promote the separation efficiency of the redox sites and the photogenerated electrons and holes. As a result, it could further enhance the performance of photocatalytic water splitting for hydrogen production. The influence mechanisms of surface and interface control for the performance of photocatalytic water splitting will also be studied systematically. Besides, the intrinsic correlation between the surface and interface structures and the photocatalytic performance will be revealed, and the structure-performance relationship of them will be built. This work will provide the scientific evidences for further developing photocatalysts with highly efficient and stable water splitting performance.

光催化分解水制氢作为新型低碳清洁能源制备技术应用前景巨大。高效催化剂的开发，是克服催化剂量子效率低的缺点，促使该技术向产业化推进的关键。钙钛矿NaTaO3晶体可塑性强，有望通过改性成为最优秀的光解水催化剂之一。但NaTaO3晶体仅对紫外光响应，且内部结构复杂，Ta-O键不易断裂，表界面结构调控难度大。如何通过优化表界面结构提高光解水性能和可见光利用率一直是NaTaO3晶体改性研究的重大科学难题。本项目拟通过调节合成反应参数，制备高比例裸露高表面能晶面及不同晶面共存的NaTaO3纳米晶，并通过光沉积贵金属和窄禁带半导体构筑晶面选择性的异质界面结构，利用表面和界面结构的协同作用，拓宽催化剂光谱响应范围、高效分离光生电子和空穴，以及氧化和还原位点，进一步提高光解水制氢性能。系统研究表界面结构调控对光解水性能的影响机制，揭示二者的本质联系，建立构-效关系，为开发高效稳定的光解水催化剂提供科学依据。

催化合成技术广泛应用于能源、环境和精细化工等领域，光催化分解水制氢、光催化降解有机污染物、催化加氢合成医药中间体等都是典型的催化合成技术的应用。然而，催化剂效率低是上述催化合成反应中普遍存在的问题。解决这一问题的关键在于高性能催化剂的设计和开发。本项目通过调节合成反应参数，优化催化剂表界面结构，开展了如下工作：（1）可控制备组分和结构不同的准立方体NaNb1-xTaxO3系列催化剂，在无表面贵金属组分的情况下，光催化分解水制氢性能最高达到1037.5 μmol·g-1；（2）调控Ru/NaNbO3系列催化剂表界面结构，获得高性能光催化降解液相RhB和Cr（VI）离子的Ru/NaNbO3催化剂，以及α-蒎烯100.0%选择性加氢转化为cis-蒎烷的Ru/APTS/NaNbO3催化剂；（3）利用简单的溶剂热联合光还原技术，可控制备Rh/NaNbO3系列催化剂，在室温和低压下实现苯甲酸100.0%选择性加氢转化为环己甲酸；（4）室温下组装合成钌-单宁酸（RuIII-TA）网络结构壳层，并以此为模板剂通过组合贵金属Pd纳米粒子和介孔SiO2不同结构单元来调控BiVO4的界面电子结构，设计合成了一系列高量子效率的新型BiVO4三元异质复合光催化材料。与上述催化剂设计开发的同时，还系统研究了催化剂合成和表界面结构调控规律，明确特殊表界面结构上活性位点、活性物种的形成和作用机制，揭示表界面结构调控对催化反应性能的影响机理，建立构-效关系，为开发应用于能源、环境和精细化工等领域合成反应的高效稳定的催化剂提供科学依据。