【作者】 叶国梁；

【导师】 黎四芳；

【作者基本信息】 厦门大学 ， 化学工程， 2009， 硕士

【摘要】 半导体光催化剂近年以无选择性、深度氧化完全的优点在空气和水体中有机及无机污染物去除的环境修复领域中得到广泛的研究和应用,其被认为是最有前景及最有效的环境净化技术。甲醛作为室内空气主要污染物之一,其去除研究具有重要意义。本文主要研究了TiO₂的制备、表征以及空气中甲醛的光催化降解。主要包括TiO₂的制备、各种表征手段、空气中甲醛光催化反应过程中的影响因素、光催化剂的重复利用和活化情况以及与其它不同方法制备的TiO₂的活性的比较。本文采用一种新颖的方法制备出高催化活性的超细纳米TiO₂。探讨了其最佳的制备条件。同时,应用XRD、BET、DSC、Raman、SEM、TEM、FT-IR、DRS等表征手段对所制备的催化剂进行表征,对TiO₂晶型、比表面积、热力学性质、表面结构、表面形貌以及对光响应等物理化学性质进行分析测定。通过这些表征分析可以得出,本方法制备的TiO₂在无需煅烧的的低温条件下已经具有较高锐钛矿型结晶度,相比目前其他低温制备方法,本方法操作简单,无需昂贵的设备。本文以甲醛为处理对象,研究了其水溶液及气相甲醛的光催化降解,系统地研究了TiO₂对气相甲醛的光催化氧化过程中各影响因素。同时,为了克服空气中甲醛浓度较低及催化剂回收利用等问题,本实验研究中将TiO-2负载到活性炭纤维（ACF）上,利用ACF的高比表面积和对甲醛的较强的吸附能力,将甲醛富集到催化剂表面,从而提高甲醛光催化氧化速率及降解率。所制备的TiO₂/ACF复合催化剂对甲醛的光催化降解可以达到100%,较其它方法所制备的TiO₂催化剂具有更高的催化活性。同时,对重复性实验和条件实验的研究中发现,本研究所制备的催化剂具有比较稳定的催化活性,具有较强的应用性。更多还原

【Abstract】 Semicoductor photocatalysis has been widely studied and applied recently in the environmental remediation field of removing organic and inorganic pollutants in the water and air because of its no selectivity and complete oxidation.It has been regarded as the most promising and efficient environmental purification technology. As one of the major indoor pollutants,the removing of indoor formaldehyde is of great significance.The dissertation studied the preparation,characterization of TiO₂ and the degradation of air formaldehyde by photocatalytic oxidation process of TiO₂.The research mainly included the preparation method,the characterization technique of TiO₂ photocatalyst,the series of factors on photocatalytic reaction process,the reuse of TiO₂ and its activation,and the comparison with different TiO₂ which were prepared in different ways were also explored.A novel route to prepare ultrafine TiO₂ with high photocatalytic activity was studied in this thesis.And the optimal preparation condition was also discussed.XRD, BET,DSC,Raman,SEM,TEM,FT-IR and DRS were applied to characterize the crystallinity,BET surface areas,thermodynamics property,surface structure, morphology,the response to the UV-vis light and other physico-chemical properties of TiO₂.According to the characterization,it can be concluded that the high crystalline nano-anatase TiO₂ was formed at a low temperature without further calcination at high temperature.Comparing with other low temperature preparation method,this method was simple and the expensive equipment was no necessary.The photodegradation of gaseous and liquid formaldehyde was studied,especially the gaseous formaldehyde,the series of factors on photocatalytic reaction process to the gaseous formaldehyde has been investigated systematically.To resolve the problems of low-level formaldehyde gas and the recycle use of TiO₂,in this research TiO₂ was loaded onto active carbon film（ACF） which has high BET surface and strong adsorbent ability to formaldehyde,to enrich the formaldehyde to the catalysis surface, accelerated the photocatalytic speed and degradation ratio of formaldehyde.It can be concluded that the photodegradation ratio of the prepared TiO₂/ACF catalyzer to formaldehyde can achieved 100%under a certain condition of humidity,velocity of flow,initial concentration.Comparing with other TiO₂ prepared in different methods, it showed higher photocatalytic activity.Repeated experiments and condition experiments showed stable catalytic activity of the prepared TiO₂/ACF.更多还原