【作者】 王飞；

【导师】 黄柏标； 王朋；

【作者基本信息】 山东大学 ， 材料学， 2021， 硕士

【摘要】 当今社会,随着科学技术的快速发展,人们的生活水平大幅提高,环境和能源问题成为了人们急需解决的两大问题。自20世纪80年代Fujishima等人首次报道了 TiO2在光照时能够分解水产氢以后,众多研究者投入到光催化的研究当中,经过数十年的发展,光催化技术迅猛发展,成为新世纪有望解决环境能源问题的新兴技术。目前光催化技术的应用主要集中在污染物降解、分解水产氢、二氧化碳还原、固氮等方面,且有些方面的应用已经逐渐投入产业化,有着广阔的应用前景。然而,光催化技术在应用时存在的两个瓶颈始终难以突破,即光响应范围窄、量子效率低。若能采取有效手段提高光催化剂的光响应以及量子效率,将对光催化技术的快速发展具有重要意义。贵金属纳米颗粒(NPs)的表面等离子体共振效应可以增强催化剂的光吸收,并且贵金属纳米颗粒的存在能够提高电子空穴的分离效率,因此,本论文重点研究的是表面等离子体光催化剂在光催化中的应用。主要内容如下:第一章,首先介绍了半导体光催化的研究背景,光催化剂的类型,光催化机理,光催化应用以及半导体光催化的制约因素,然后介绍了表面等离子体光催化剂的研究现状、合成方法、反应机理、应用以及存在的问题。最后阐释本论文的选题意义以及选题内容。第二章,主要介绍了 Ag/AgCl表面等离子体光催化剂在降解甲烷方面的应用。通过简单的共沉淀法合成了一种类立方体型的Ag/AgCl表面等离子体光催化剂,其在甲烷的光降解方面具有良好的稳定性和几乎100%的矿化效率。且在甲烷降解方面,Ag/AgCl的光降解效率是TiO2的35倍。经过系统的实验以及时域有限差分法模拟计算表明,AgNPs的表面等离子体共振效应能够产生强的电场,使非极性气体分子产生极化,促进催化剂对极化后的甲烷分子的吸附,从而导致甲烷气体分子的有效降解。这项研究拓展了使用等离子体光催化剂来降解气态的非极性分子的思路。第三章,主要介绍了 Ag/AgCl表面等离子体光催化剂在选择性氧化硫醚到亚砜方面的应用。通过简单的一步法合成了 Ag/AgX(X=Cl、Br、I)表面等离子体光催化剂。在模拟太阳光照射下,合成的Ag/AgCl在硫醚类的选择性转化方面展现出接近100%的选择性和转化率,与传统的转化方法相比更加绿色、环保、经济、高效。且我们通过系统的实验以及活性物种检测法,探讨了其性能好的原因,结果表明,银纳米颗粒的表面等离子体共振效应可以拓宽光吸收,并且提供更多的活性位点,从而促进硫醚类的选择性转化。我们在研究中提出了这项工作的可能的光催化机理,这为Ag/AgX表面等离子体光催化剂在有机物选择性转化方面的应用开辟了道路,也为其在有机物选择性转化方面的应用提供了新的思路。第四章,对本文论的工作进行了总结,并分析了论文中的创新点和仍然存在的问题,最后对下一步的工作进行了展望。更多还原

【Abstract】 In today’s society,with the rapid development of science and technology,people’s living standards have greatly improved,and environmental and energy issues have become two major issues that people need to solve urgently.Since Fujishima and others first reported in the 1980s that TiO2 can decompose water to produce hydrogen under light,many researchers have devoted themselves to the research of photocatalysis.After decades of development,the rapid development of photocatalysis technology has become a promising solution in the new century.Photocatalytic technology is expected to be a new technology to solve environmental pollution and energy shortage.At present,the application of photocatalytic technology is mainly concentrated in the aspects of pollutant degradation,decomposition of water to produce hydrogen,carbon dioxide reduction,nitrogen fixation,etc.,and some applications have been gradually put into industrialization,and have broad application prospects.However,it is always difficult to break through the two bottlenecks in photocatalysis applications,which are narrow light response range and low quantum efficiency.If effective measures can be taken to improve the photoresponse and quantum efficiency of the photocatalyst,it will be of great significance to the rapid development of photocatalysis technology.The surface plasmon resonance effect of noble metal nanoparticles can enhance the light absorption of the catalyst,and the presence of noble metal nanoparticles can improve the separation efficiency of electrons and holes.Therefore,this paper focuses on the application of surface plasmonic photocatalysts in photocatalysis.The main contents are as follows:The first chapter first introduces the research background of semiconductor photocatalysis,the types of photocatalysts,the mechanism of photocatalysis,the application of photocatalysis and the restrictive factors of semiconductor photocatalysis.Then the research status,synthesis method,reaction mechanism,application and existing problems of surface plasmonic photocatalyst are introduced.Finally,it explains the meaning and content of the topic selection of this thesis.The second chapter mainly introduces the application of Ag/AgCl surface plasmonic photocatalyst in the degradation of methane.The methane degradation rate of Ag/AgCl is approximately 35 times higher than that of TiO2.Systematic experiments and finite-difference time-domain simulated calculations results demonstrate that the SPR effect of Ag NPs can generate a strong electric field,which can polarize the non-polar molecules,make them be adsorbed and lead to the efficient gas degradation.This study broadens the idea of using plasmonic photocatalysts to eliminate gaseous non-polar molecules.The third chapter mainly introduces the application of Ag/AgCl surface plasmonic photocatalyst in the selective oxidation of sulfide to sulfoxide.The Ag/AgX(X=Cl,Br,I)surface plasmonic photocatalyst was synthesized by a simple one-step method.Under simulated sunlight,the synthesized Ag/AgCl exhibits close to 100%selectivity and conversion rate in the selective conversion of thioethers,which is more green,environmentally friendly,economical and efficient than traditional conversion methods.We have discussed the reasons for its good performance through systematic experiments and active species detection methods.The results show that the surface plasmon resonance effect of silver nanoparticles can broaden light absorption and provide more active sites,thereby promoting the selective conversion of thioethers.In our research,we put forward the possible photocatalytic mechanism of this work,which paves the way for the application of Ag/AgX surface plasmonic photocatalyst in the selective conversion of organic matter.It also provides a new idea for its application in the selective conversion of organic matter.The fourth chapter summarizes the work of this article,analyzes the innovations and still existing problems in the thesis and finally looks forward to the next step of the work.更多还原