光催化分解水制取氢气的Ag/TiO2组装结构基于表面等离子体光子学原理的两种设计

The photochemical splitting of water to form H2 and O2 is of critical importance for the development of a sustainable energy in the future.?Recently plasmonic nanostructures of noble metals (mainly silver) also show significant promise. The nanocomposite of Ag/TiO2 can still be used for this plasmonic process,but the photocatalysis mechanism has shown inversional change. Namely the acceptor of light illumination?is no longer TiO2 but nanosized silver. .Herein the silver plasmonic factors related to its size, shape and interaction with TiO2 nanoparticle will be investigated carefully, to obtain efficient conversion of solar energy into fuels, including using visible-light as illumination source,increasing H2 involution speed and so on. The research consistes of two methods. In method 1, self-assembled TiO2 nanowires array can be templated by cetyl trimethylammonium bromide (CTAB). Then the silver nanomaterials can be obtained by the reaction of Br- from template with Ag+ form AgNO3 and decomposition of AgBr,and the size and shape of silver nanomaterials will be controlled by the template (CTAB)or additional polymers.Thus the silver nanomaterials can be loaded into TiO2 nanowire layer. In method 2, traditional Ag/TiO2 composite structure will be improved. The content of silver in composite will be increased and TiO2 nanoparticles are fixed on the surface of silver nanoslice with the distribution of low-density by hydrothermal treatment.Thus, silver nanoslice can be illuminated effectively by visible-light.

光催化分解水制取氢气的研究至今仍是科学界的热点问题。最近，基于表面等离子体光子学原理的相关光催化研究又引起较大关注，该方法使用的催化剂仍可采用金属单质/TiO2等传统复合体，但此时光催化原理已发生颠倒性变化，即光辐射的有效接受体不是TiO2而是某些纳米化金属单质。.本研究旨在通过控制纳米Ag的尺寸、几何形状以及和TiO2的结合方式等手段，提高分解水制取氢气的效率，包括可见光的有效利用，产氢速度的提高等。方法1，采用十六烷基三甲基溴化铵（CTAB）作模版，首先获得TiO2纳米线自组装阵列结构，再充分利用模版CTAB的功能：（1）通过AgNO3与模版中的Br-反应等过程获取Ag单质；（2）CTAB等可继续控制纳米Ag的形貌。这样可生成纳米Ag/TiO2纳米线的交替复合结构。方法2，改进传统做法，适当提高Ag在复合体中的含量，将纳米TiO2低密度组装到纳米Ag片表面，促成纳米Ag有效接受光辐照。

贵金属纳米粒子具有独特的表面等离子体共振效应，可以在可见光的辐照下产生光生电子空穴对，电子可以转移到半导体的导带上，促进光生载流子的分离，进而提高光催化活性。本课题利用表面等离子体共振效应，主要研究了基于银/二氧化钛纳米复合结构并拓展与延伸了相应光催化的问题探索，主要包括Ag/TiO2纳米复合结构及其光催化性能和抗菌性能、Ag/ZnO纳米复合结构及其光催化分解水制氢性能、Au/TiO2纳米复合结构及其光催化分解水制氢性能、Au/ZnO纳米复合结构及其光催化降解染料和光催化氧化甲醇的性能、沿[001]取向的锐钛矿TiO2介晶及其光催化分解水制氢性能、单分散的BiVO4@TiO2复合光催化剂及其光催化降解有机污染物性能、Bi掺杂的锐钛矿空心TiO2薄片光催化剂及其光催化降解染料性能和C,N-TiO2 NPs/g-C3N4光催化剂及其光催化分解水制氢性能，积极探索了金属氧化物半导体等材料在光催化领域的应用。