Lin Hua-Jian, Xu Shuai, Fu Xiao-Yan, Wei Zhi-Quan, Huang Ming-Hui, Lin Xin, He Yunhui, Xiao Guangcan, Xiao Fang-Xing
College of Materials Science and Engineering, Fuzhou University, New Campus, Minhou, Fujian Province 350108, People's Republic of China.
Instrumental Measurement and Analysis Center, Fuzhou University, Fuzhou 350002, People's Republic of China.
Inorg Chem. 2020 Mar 16;59(6):4129-4139. doi: 10.1021/acs.inorgchem.0c00229. Epub 2020 Mar 6.
The capability of noble metal nanoparticles (NPs) as efficient charge transfer mediators to stimulate Schottky-junction-triggered charge flow in multifarious photocatalysis has garnered enormous attention in the past decade. Nevertheless, fine-tuning and controllable fabrication of a directional charge transport channel in metal/semiconductor heterostructures via suitable interface engineering is poorly investigated. Here, we report the progressive fabrication of a tailor-made directional charge transfer channel in Pt nanoparticles (NPs)-inlaid WO (Pt-WO) nanocomposites via an efficient electrostatic layer-by-layer (LbL) self-assembly integrated with a thermal reduction treatment, by which oppositely charged metal precursor ions and polyelectrolyte building blocks were intimately and alternately assembled on the WO nanorods (NRs) by substantial electrostatic interaction. LbL self-assembly buildup and in situ self-etching-induced structural variation of WO NRs to a microsized superstructure occur simultaneously. We found that such exquisitely crafted Pt-WO nanocomposites exhibit conspicuously enhanced and versatile photoactivities for nonselective mineralizing of organic dye pollution and reduction of heavy metal ions at ambient conditions under both visible and simulated sunlight irradiation, demonstrating a synergistic effect. This is attributed to the imperative contribution of Pt NPs as electron traps to accelerate the directional high-efficiency electron transport from WO to Pt NPs, surpassing the confinement of electron transfer kinetics of WO owing to low conduction level. More intriguingly, photoredox catalysis can also be triggered simultaneously in the same reaction system. The primary in situ produced active species in the photocatalytic reactions were specifically analyzed, and underlying photocatalytic mechanisms were determined. Our work would provide a universal synthesis strategy for constructing various metal-decorated semiconductor nanocomposites for widespread photocatalytic utilizations.
在过去十年中，贵金属纳米颗粒（NPs）作为高效电荷转移介质，在多种光催化中刺激肖特基结触发的电荷流动的能力引起了极大关注。然而，通过合适的界面工程在金属/半导体异质结构中微调并可控地制造定向电荷传输通道的研究却很少。在此，我们报告了通过高效的静电逐层（LbL）自组装与热还原处理相结合，在镶嵌铂纳米颗粒（Pt NPs）的WO（Pt-WO）纳米复合材料中逐步制造定制的定向电荷转移通道，通过这种方法，带相反电荷的金属前驱体离子和聚电解质构建块通过大量静电相互作用在WO纳米棒（NRs）上紧密且交替组装。LbL自组装的形成以及WO NRs原位自蚀刻诱导的结构向微尺寸超结构的变化同时发生。我们发现，这种精心制作的Pt-WO纳米复合材料在可见光和模拟太阳光照射下的环境条件下，对有机染料污染的非选择性矿化和重金属离子的还原表现出显著增强且通用的光活性，证明了协同效应。这归因于Pt NPs作为电子陷阱的重要贡献，可加速从WO到Pt NPs的定向高效电子传输，超越了由于低导带水平导致的WO电子转移动力学的限制。更有趣的是，在同一反应体系中还能同时触发光氧化还原催化。具体分析了光催化反应中原位产生的主要活性物种，并确定了潜在的光催化机制。我们的工作将为构建各种用于广泛光催化应用的金属修饰半导体纳米复合材料提供一种通用的合成策略。
