Department of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kerala, India.
Nanotechnology and Bio-engineering Research Group, Department of Environmental Science, Institute of Technology Sligo, Sligo, Ireland; Centre for Precision Engineering, Materials and Manufacturing Research (PEM), Institute of Technology Sligo, Sligo, Ireland.
Chemosphere. 2021 May;271:129506. doi: 10.1016/j.chemosphere.2020.129506. Epub 2021 Jan 2.
Nanostructured photocatalysts have always offered opportunities to solve issues concerned with the environmental challenges caused by rapid urbanization and industrialization. These materials, due to their tunable physicochemical characteristics, are capable of providing a clean and sustainable ecosystem to humanity. One of the current thriving research focuses of visible-light-driven photocatalysts is on the nanocomposites of titanium dioxide (TiO) with carbon nanostructures, especially graphene. Coupling TiO with graphene has proven more active by photocatalysis than TiO alone. It is generally considered that graphene sheets act as an electron acceptor facilitating the transfer and separation of photogenerated electrons during TiO excitation, thereby reducing electron-hole recombination. This study briefly reviews the fundamental mechanism and interfacial charge-transfer dynamics in TiO/graphene nanocomposites. Design strategies of various graphene-based hybrids are highlighted along with some specialized synthetic routes adopted to attain preferred properties. Importantly, the enhancing interfacial charge transfer of photogenerated e¯ through the graphene layers by morphology orientation of TiO, predominated exposure of their high energy crystal facets, defect engineering, enhancing catalytic sites in graphene, constructing dedicated architectures, tuning the nanomaterial dimensionality at the interface, and employing the synergism adopted through various modifications, are systematically compiled. Portraying the significance of these photocatalytic hybrids in environmental remediation, important applications including air and water purification, self-cleaning surfaces, H production, and CO reduction to desired fuels, are addressed.
纳米结构光催化剂一直为解决城市化和工业化快速发展所带来的环境挑战问题提供了机会。这些材料具有可调谐的物理化学特性，能够为人类提供清洁和可持续的生态系统。目前可见光驱动光催化剂的一个热门研究焦点是二氧化钛（TiO）与碳纳米结构的纳米复合材料，特别是石墨烯。将 TiO 与石墨烯结合已被证明比单独的 TiO 具有更高的光催化活性。一般认为，石墨烯片作为电子受体，有利于在 TiO 激发过程中光生电子的转移和分离，从而减少电子-空穴复合。本研究简要综述了 TiO/石墨烯纳米复合材料中的基本机制和界面电荷转移动力学。强调了各种基于石墨烯的杂化设计策略，以及采用的一些特殊合成路线，以获得所需的性质。重要的是，通过 TiO 的形态取向、高能量晶面的优先暴露、缺陷工程、增强石墨烯中的催化位点、构建专用结构、调整界面处纳米材料的维度，以及通过各种修饰采用协同作用，来增强光生电子的界面电荷转移，这些策略被系统地总结。通过描绘这些光催化杂化在环境修复中的重要意义，包括空气和水净化、自清洁表面、H2 生产以及 CO 还原为目标燃料等重要应用。
