Hybrid nanomaterials and their structure-property-performance relations for catalysis, green energy and nanoelectronics applications

在过去的五年里，我们在(A)生物/有机分子在硅单晶表面的界面化学，以及(B)过渡金属(及其氧化物)和透明导电氧化物在硅和其他(模板)衬底上的纳米结构方面取得了许多重要的研究成果。由于材料和结构缺陷已成为整个材料中往往不可避免但又极其重要的一部分，我们将在未来五年内将重点放在这些杂化纳米材料中的缺陷驱动现象上。虽然缺陷的存在通常被认为对某些材料的性能有害，但对这些缺陷的控制也可以对一些重要的材料性能非常有利，特别是当材料尺寸接近纳米级时。我们最近在富缺陷的二氧化钛纳米线中发现了非凡的光催化能力，用于水的分解反应(用于氢燃料电池)，证明了这一点。我们的使命是研究基准纳米材料中的缺陷，并更好地了解它们在不同生长、加工或处理策略下的形成和演化机制。主要的三类纳米材料是(按大小递增的顺序)：超小纳米团簇(5 Nm)、纳米晶体(5-100 nm)以及过渡金属(及其氧化物)和透明导电氧化物的低维纳米结构。我们的目标是开发协议来处理这些缺陷，并优化缺陷控制材料的结构-性能-性能关系，用于化学传感和药物输送、绿色能源和纳米电子学。我们将利用滑铁卢大学核心材料研究机构提供的一整套先进材料表征和合成工具来调查几个基本问题。其中包括：(A)纳米团簇中特定部位缺陷的化学作用与团簇大小的关系；(B)纳米结构中缺陷形成的机制；(C)生物/有机吸附物与不同缺陷部位组成的纳米团簇和纳米结构的相互作用；以及(D)底物效应。这些实验将得到大规模从头计算研究的支持，以获得对这些基本概念的新见解。拟议的工作还将使我们能够充分利用这些新的缺陷控制的混合纳米材料用于重要的新兴应用，包括多路化学传感和药物输送，以改进我们的医学研究工具；用于将水分解为太阳能制氢的超高效光催化剂，以增加我们的绿色能源能力和减少全球变暖；以及忆阻器，作为下一代纳米电子产品，将我们推向一个没有晶体管的世界。

In the past five years, we have achieved a number of important studies on the interfacial chemistry of (a) bio/organic molecules on Si single-crystal surfaces, and (b) nanostructures of transition metals (and their oxides) and transparent conductive oxides on Si and other (templated) substrates. As material and structural imperfections have become an often unavoidable yet extremely important part of the entire material, we will focus, in the next five years, on defects-driven phenomena in these hybrid nanomaterials. While the presence of defects is often viewed as detrimental to some material properties, control of these defects can also be highly beneficial to a number of important material properties, especially when the material size approaches the nanoscale. This has been demonstrated by our recent discovery of extraordinary photocatalytic power in defect-rich TiO2 nanowires for the water-splitting reaction (for hydrogen fuel cell application). Our mission is to study defects in benchmark nanomaterials and to obtain better understanding of their formation and evolution mechanisms in different growth, processing or treatment strategies. The three primary classes of nanomaterials of particular interest are (in the order of increasing size): ultrasmall nanoclusters (< 5 nm), nanocrystallites (5-100 nm), and low-dimensional nanostructures of transition metals (and their oxides) and transparent conductive oxides. Our objective is to develop protocols to manipulate these defects and to optimize the structure-property-performance relations of defect-controlled materials for applications in chemical sensing and drug delivery, green energy, and nanoelectronics. We will employ the full fleet of advanced materials characterization and synthesis tools available at the core material research facility at the University of Waterloo to investigate several fundamental questions. These include: (a) the chemistry of site-specific defects in nanoclusters as a function of cluster size; (b) mechanisms of defect formation in nanostructures; (c) interactions of bio/organic adsorbates with nanoclusters and nanostructures with different defect-site compositions; and (d) substrate effects. These experiments will be supported by large-scale ab-initio computational studies in order to obtain new insights into these basic concepts. The proposed work will also allow us to fully exploit the use of these new defect-controlled, hybrid nanomaterials for important emerging applications, including multiplex chemical sensing and drug delivery to advance our medical research tools, super-efficient photocatalysts for water splitting for solar-to-hydrogen generation to increase our green energy capacity and to reduce global warming, and memristors as the next-generation nanoelectronics to propel us to a transistor-free world.