Fabrication and Characterization of Visible-Light-Driven Plasmonic Photocatalyst Ag/AgCl/TiO2 TiO2 Nanotube Arrays
Fabrication and Characterization of Visible-Light-Driven Plasmonic Photocatalyst Ag/AgCl/TiO2 TiO2 Nanotube Arrays
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DOI：
10.1021/jp905247j
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发表时间：
2009-09-17
影响因子：
3.7
通讯作者：
Huang, Baibiao
中科院分区：
文献类型：
--
作者：
Yu, Jiaguo;Dai, Gaopeng;Huang, Baibiao
传统的TiO 2光催化剂具有优异的活性和稳定性，但需要近紫外（UV）照射（约太阳光谱的4%）才能有效降解，从而严重限制了其实际应用。非常希望开发一种在太阳光照射下能够高效利用可见光的光催化剂。在这项工作中，我们制备了新的可见光驱动的等离子体光催化剂Ag/AgCl/TiO 2纳米管阵列（NTs）通过沉积AgCl纳米颗粒（NPs）到自组织的TiO 2 NTs，然后在氙灯照射下还原部分Ag+离子的表面区域的Ag-0物种。所制备的金属-半导体纳米复合等离子体光催化剂对水中的甲基橙橙子具有较高的可见光光催化降解活性和稳定性。一种新的等离子体光催化机制，这是提出的事实的基础上，银纳米粒子的光激发，由于等离子体共振和电荷分离，是通过光激发的电子从银纳米粒子的TiO 2导带的转移和同时转移的补偿电子从供体（Cl-）的银纳米粒子。羟基自由基实验和瞬态光电流响应实验进一步证实了上述机理。所制备的光催化剂在太阳能电池、催化、分离技术、生物医学工程、纳米技术等领域也具有重要的应用价值。该研究为新型可见光催化材料的设计和制备提供了新的思路。
Conventional TiO2 photocatalyst possesses excellent activities and stabilities, but requires near-ultraviolet (UV) irradiation (about 4% of the solar spectrum) for effective photocatalysis, thereby severely limiting its practical application. It is highly desirable to develop a photocatalyst that can use visible light in high efficiency under sunlight irradiation. In this work, we prepare new visible-light-driven plasmonic photocatalyst Ag/AgCl/TiO2 nanotube arrays (NTs) by depositing AgCl nanoparticles (NPs) into the self-organized TiO2 NTs, and then reducing partial Ag+ ions in the surface region of the AgCl particles to Ag-0 species under xenon lamp irradiation. The prepared metal-semiconductor nanocomposite plasmonic photocatalyst exhibits a highly visible-light photocatalytic activity for photocatalytic degradation of methyl orange in water and stability. A new plasmonic photocatalytic mechanism, which is proposed on the basis of the fact that the Ag NPs are photoexcited due to plasmon resonance and charge separation, is accomplished by the transfer of photoexcited electrons from the Ag NPs to the TiO2 conduction band and the simultaneous transfer of compensative electrons from a donor (Cl-) to the Ag NPs. The proposed mechanism is further confirmed by the experiments of hydroxyl radical and transient photocurrent response. The prepared photocatalysts are also of great interest in solar cell, catalysis, separation technology, biomedical engineering, and nanotechnology. This study may provide new insight into the design and preparation of advanced visible-light photocatalytic materials.