可调控表面等离子共振金纳米棒/近红外光催化材料表面异质结构的构建及其光催化机理研究

The essential factor for efficient photocatalytic degradation of pollutants is to expand the spectrum of sunlight utilization. The near-infrared (NIR) light occupies 44% solar spectrum. However, there is no effective photocatalyst, which can use the NIR light. Until recent years, several NIR photocatalysts, such as up-converted materials, Bi2WO6, and Cu2(OH)PO4, were found. But these NIR photocatalysts only have a single NIR photocatalytic effect or their photocatalytic efficiencies are low due to their insufficient NIR light absorption. The gold (Au) nanorods with surface plasmon resonance (SPR) effects can achieve continuous enhancement of visible and NIR light absorption by regulating the parameters. In this study, Au nanorods are assembled onto the surface of NIR photocatalysts to construct surface heterostructure. The proposal will focus on the investigation on enhanced visible and NIR photocatalytic mechanism by studying light absorption, conversion, transfer and recombination of light-induced carrier in heterostructure through physical spectra, theoretical simulation and experimental study. In addition, the SPR effects of Au nanorods on the enhancement of activity of NIR photocatalyst will be addressed. After understanding the enhanced visible and NIR photocatalytic mechanism, design and synthesis of high performance wide spectrum (enhanced NIR photocatalytic effect and broadened visible photocatalytic range) of Au nanorod/NIR photocatalyst surface heterostructures can be achieved.

有效利用太阳光进行光催化降解污染物的基本要求是拓展太阳光利用的光谱范围。然而，太阳光谱中占总能量44%的近红外波段，一直没有被有效利用。直到近几年，上转换材料，Bi2WO6，Cu2(OH)PO4等近红外光催化材料被发现。但是这几种近红外光催化材料仍存在仅具有单一近红外光催化效果和近红外光催化效率较低缺点。金纳米棒具有表面等离子共振（SPR）效应，通过调控可以在可见与近红外光范围内实现对光谱的连续增强吸收。本研究以近红外光催化材料为载体，在其表面负载金纳米棒，构建金纳米棒/近红外光催化材料表面异质结构，通过物理光谱测试、理论模拟计算和实验研究解释光吸收、转化和光生载流子的传输与复合机理，特别关注金纳米棒的SPR吸收峰对可见与近红外光催化性能的增强效果，阐明增强光催化机理，最终设计和合成太阳光宽光谱光催化（增强近红外光催化效果和拓宽可见光催化范围）的金纳米棒/近红外光催化材料表面异质结构。

拓宽光吸收范围和促进光生电荷分离是提高光催化性能的两个重要途径。本课题为了改善光催化性能，利用金纳米棒的表面等离子共振效应，窄禁带宽度Ag2O、VS4、Ag2S、In2S3等半导体促进近红外光吸收得到了性能优异的高效近红外光催化材料；通过将可见或近红外光吸收材料与TiO2构建表面异质结构，进一步得到了太阳光全光谱响应的光催化材料，此外还进一步研究传统异质结构和Z-scheme新型异质结构对促进光生电荷分离方面的具体反应机理，得到异质结构光催化反应机制；进一步拓宽表面异质结构的应用，利用表面异质结构制备了纳米纸张，设计并实现了高效的气相催化，对不同的表面异质结构的气敏特性进行了研究，得到了高性能的气敏测试原型器件。在资金的支持下，还时对多孔纳米材料的电催化性能进行了初步的探索。课题开展过程中共发表SCI收录论文24篇，其中影响因子10以上论文3篇。获授权发明专利1项，申请发明专利4项。相关研究成果对于丰富光催化材料理论及技术，扩大光催化材料应用，推动工业废气和废液治理，对于减排、降耗等具有重要意义。