Surface-plasmon-enhanced photocatalytic H2 generation and CO2 conversion over metal nanoparticles

本研究的主要目的是设计和开发能够有效捕获和利用太阳能转化为化学能的可见光敏感光催化剂。为了拓展等离子体纳米催化剂的研究，我们在不同形貌的TiO 2载体材料上制备了Au纳米粒子（NPs），并将其与不同碱金属氢氧化物（NaOH、KOH和LiOH）在400 K下水热处理30 h，制备了不同形貌的TiO 2（纳米管、纳米棒和微孔）。这些TiO 2纳米管/纳米棒/微孔颗粒，然后用于容纳Au NPs进行光催化反应，因为它的高表面积和大孔体积。结果表明，在可见光照射下，Au纳米粒子的等离子体激发能显著增强苯甲醇的有氧氧化反应，尤其是以TiO 2纳米管和纳米棒为载体的情况。光谱分析表明，Au纳米粒子的局域表面等离子体共振引起的电荷分离效应导致了基底的同时氧化和还原（电子供体）和O2虽然尚未进行利用该Au/TiO 2等离子体激元催化剂来产生H2和还原CO2的扩展研究，我们预测，这种利用太阳能设计新催化剂的进展必将促进清洁光催化系统的发展。

The main purpose of this research is to design and develop visible-light sensitive photocatalysts which can efficiently capture and utilize the available solar energy to chemical energy. To extend the research studies on plasmonic nanocatalysts, we synthesized Au nanoparticles (NPs) on different morphologies of TiO2 support material.Different morphologies of TiO2 (nanotube, nanorod and microporous) were prepared by the hydrothermal treatment of anatase TiO2 with different alkali hydroxides such as NaOH, KOH and LiOH at 400 K for 30 h. These TiO2 nanotube/nanorod/microporous particles were then used to accommodate Au NPs for carrying out the photocatalytic reaction because of its high surface area and large pore volume. It was observed from the reaction results that the aerobic oxidation of benzyl alcohol was significantly enhanced by the plasmonic excitation of Au NPs under visible light irradiation, especially in the case of TiO2 nanotube and nanorod as the support material. Based on spectroscopic analyses, it was concluded that the charge separation effect arising from the localized surface plasmon resonance of Au NPs caused a simultaneous oxidation and reduction of substrate (electron donor) and O2 (electron acceptor) at different sites.Although extended studies utilizing this Au/TiO2 plasmonic catalyst to H2 production and CO2 reduction have not been done yet, we predict that such progress in the design of new catalysts by utilizing solar energy will definitely foster the development of clean photocatalytic system.