【作者】 李爽；

【导师】 林艳红；

【作者基本信息】 吉林大学 ， 材料与化工（专业学位）， 2023， 硕士

【摘要】 水体污染问题随着工业的发展而日趋严重,传统的污水处理手段已不足以应对更加复杂和多样化的污染物,因此开发并利用高效环保的污水处理技术是解决水污染问题的重点所在。光催化-芬顿技术联合了光催化氧化技术和芬顿氧化技术,是一种绿色高效的技术手段,可广泛应用于降解污染物领域。在诸多半导体光催化材料中,二氧化钛（TiO₂）半导体因其成本低廉、结构稳定、光学性能优良等特点,在光催化领域成为首选半导体材料之一,受到广泛的研究和应用。然而,TiO₂带隙较宽（～3.2 e V）,只能吸收紫外光,而太阳光的组成中大部分为可见光,导致单纯的TiO₂无法被太阳光有效激发,对太阳光的低利用率限制了TiO₂的实际应用。另外,TiO₂还存在着光生电荷复合率高的缺点,导致能够发挥作用的有效电子-空穴的数量减少,使其光催化性能进一步受到抑制。因此,通过对TiO₂进行N掺杂以实现其对可见光的吸收,并以N-TiO₂为基础,与具有优异转移电子性能的芬顿试剂复合,构筑光催化-芬顿体系,实现有机污染物的高效降解。另外,针对上述材料对可见光的利用率低、实际应用性较差的问题,采用贵金属沉积的方法,实现可见光下对有机污染物的高效降解。同时利用稳态表面光电压技术和瞬态光电压技术对复合催化剂的光生电荷行为进行表征,深入探究了光生电荷行为与降解性能之间的关系。具体工作内容如下:1.采用水热法和酸浸渍法合成了N-TiO₂/Mn-HPMo光催化-芬顿复合催化剂,并将其应用于紫外-可见光下罗丹明B溶液的降解。通过紫外-可见漫反射光谱（UV-vis DRS）证明了N掺杂拓宽了TiO₂的光吸收范围至可见光区域,并利用稳态表面光电压技术和瞬态光电压技术表征复合催化剂表面和界面之间的光生电荷行为,证明了Mn-HPMo可以转移N-TiO₂的光生电子,促进光生电子-空穴的分离,有效提高了催化剂的光活性。2.利用光还原法构筑了N-TiO₂/Mn-HPMo/Ag三元复合催化剂,并将其应用于可见光下罗丹明B溶液的降解。利用紫外-可见漫反射光谱（UV-vis DRS）验证了Ag的沉积可以实现显著增强的可见光吸收,通过稳态表面光电压技术的表征证明了Ag沉积可以增强光生电荷分离效率,提供了更多光生电子参与光催化-芬顿反应。此部分工作提供了一种在可见光下有利于环境修复的且实际应用性更高的高效催化剂。更多还原

【Abstract】 The issue of water pollution has become more and more severe with the development of industry.Traditional methods of sewage treatment are no longer sufficient to deal with more complex and diverse pollutants,therefore,the exploitation and utilization of efficient and environmentally friendly technologies for sewage treatment is the focus of the problem.Photocatalysis-Fenton technology combines photocatalytic oxidation technology and Fenton oxidation technology,which is a green and efficient technical means and can be widely used in the field of degrading pollutants.Among various semiconductor photocatalytic materials,titanium dioxide（TiO₂）has become one of the preferred semiconductor materials in the field of photocatalysis due to its low cost,stable structure and excellent optical properties,and has been widely applied and studied.However,TiO₂,with a wide band gap（3.2 e V）,can only absorb ultraviolet light,while most of the composition of sunlight is visible light,leading to the fact that TiO₂ alone cannot be effectively excited by sunlight,so the inefficient utilization of sunlight restricts the practical application of TiO₂.In addition,TiO₂ has the disadvantage of high photogenerated charge complexation rate,which causes the number of effective electrons-hole that can play a role to be reduced and further inhibits its photocatalytic performance.Therefore,we achieve the absorption of visible light through N-doping of TiO₂.And on the basis of N-TiO₂,we construct a photocatalysis-Fenton system by compounding with Fenton reagent with excellent electron transfer performance to realize the efficient degradation of organic pollutants.Furthermore,in order to address the problems of low utilization of visible light and poor practical applicability of the above materials,the noble metal loading method is applied to achieve highly efficient degradation of organic pollutants under visible light.The Surface Photovoltage Technique and Transient Photovoltage Technique are employed to characterize the photogenerated charge behavior of the composites,and the connection between photogenerated charge and degradation performance is deeply investigated.The specific work is as follows:1.N-TiO₂/Mn-HPMo photocatalysis-Fenton composite catalysts were synthesized by hydrothermal and acid impregnation methods,and applied to the degradation of Rhodamine B solution under UV-vis light.It was demonstrated by UV-vis diffuse reflectance spectroscopy（UV-vis DRS）that the N doping broadened the light absorption range of TiO₂ to the visible region.The photogenerated charge behavior between the catalyst surface and interface was characterized by Surface Photovoltage Technique and Transient Photovoltage Technique,and it was exhibited that Mn-HPMo could transfer the photogenerated electrons of N-TiO₂ to achieve the effective separation of photogenerated electrons-hole.The degradation mechanism of N-TiO₂/Mn-HPMo for the degradation of Rh B was thoroughly investigated.2.N-TiO₂/Mn-HPMo/Ag ternary composite catalysts were constructed utilizing photoreduction method and applied to the degradation of Rhodamine B solution under visible light.It was verified using UV-vis diffuse reflectance spectroscopy（UV-vis DRS）that the Ag deposition could enable significantly enhanced visible light absorption,and the characterization by Surface Photovoltage Technique demonstrated that the Ag loading could increase the photogenerated charge separation efficiency and provide more photogenerated electrons to participate in the photocatalysis-Fenton reaction.This part of the work provides efficient catalysts that are conducive for environmental remediation under visible light.更多还原