Effective surface disorder engineering of metal oxide nanocrystals for improved photocatalysis
Effective surface disorder engineering of metal oxide nanocrystals for improved photocatalysis
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DOI：
10.1016/j.apcatb.2016.10.054
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发表时间：
2017-04-01
影响因子：
22.1
通讯作者：
Zhang, Shaowei
中科院分区：
文献类型：
--
作者：
Lin, Liangxu;Huang, Juntong;Zhang, Shaowei
二氧化钛 (TiO2) 等金属氧化物 (MO) 半导体通常用于许多光化学过程（例如废水修复）。然而，它们的大带隙限制了它们的催化性能。人们已经开发了各种技术来提高 TiO2 纳米晶体 (NC) 的光催化活性，例如通过化学掺杂、设计混合电子结构和产生表面紊乱。不幸的是，这些技术存在各种缺点，包括操作复杂/昂贵，以及改性 TiO2 在近红外 (IR) 光（全太阳辐射的 53%）下光活性仍然较差。在这里，我们展示了一种在 MO 半导体中引入连续内能级的简单但通用的途径，包括 TiO2、氧化锌 (ZnO) 和氧化铟 (In2O3) NC。这项新技术只需要简单地加热 MO NC 与钾 (K) 的混合物。与传统的 MO NC 不同，使用本技术制备的 NC 均为黑色，并且能够吸收几乎完整的太阳光谱。所制备的黑色 TiO2 NC 在可见光照射下光催化降解亚甲基蓝 (MB) 染料方面的性能比传统同类材料好 300 倍以上。使用所制备的 ZnO 和 In2O3 NC 也实现了类似水平的光催化性能改进。此外，我们还展示了如何将 NC 转变为具有定制电子结构的黑色 NC。我们的结果表明，NC 光活性的提高主要归因于表面无序诱导、氧 (O) 空位和与 K 反应过程中可能形成的金属相。(C) 2016 Elsevier B.V. 保留所有权利。
Metal oxide (MO) semiconductors such as titanium dioxide (TiO2) are often used in many photochemical processes (e.g. waste-water remediation). However, their large band gaps limit their catalytic performances. Various techniques have been developed to improve the photocatalytic activity of TiO2 nanocrystals (NCs), e.g., via chemical doping, designing hybrid electronic structures, and creating surface disorders. Unfortunately, these techniques suffered from various disadvantages including complex/expensive operations and still poor photoactivity of modified TiO2 under near-infrared (IR) light (53% of the full solar irradiation). Here, we demonstrate a simple but universal route to introducing continous internal energy levels in MO semiconductors, including TiO2, zinc oxide (ZnO) and indium oxide (In2O3) NCs. This new technique just requires simply heating a mixture of an MO NC with potassium (K). Distingctly from conventional MO NCs, NCs prepared using the present technique were all in black color and able to adsorb nearly full solar spectrum. As-prepared black TiO2 NCs performed >300 times better than their conventional counterparts in the photocatalytic degradation of methylene blue (MB) dye under visible light irradiation. Similar levels of improvements in the photocatalytic performance were also achieved with as-prepared ZnO and In203 NCs. In addition, we show how NCs could be changed to black ones with tailored electronic structures. Our results suggested that the improvements in the NC's photoactivity were mainly attributed to the surface disorder induced, oxygen (O) vacancies and metallic phases likely formed during the reaction process with K. (C) 2016 Elsevier B.V. All rights reserved.