摘要
界面光热水蒸发是极具研究前景的有机污水纯化技术,但也存在有机污染物在光热蒸发器表面沉积的问题.为此,本文将具有光催化效应的纳米TiO2引入到多孔泡沫碳光热吸收体中制备了复合光热催化蒸发器(CF@RT),并对复合材料的结构和光热催化性能进行了分析.结果表明,CF@RT中生长有大量直径约10nm的一维TiO2纳米棒,纳米棒均匀分散在泡沫碳表面和孔结构中;TiO2的引入有效拓宽了材料对光的响应范围,使复合材料具备光热和光催化双功能;多孔泡沫碳通过吸收可见-红外光转换为热能实现水的蒸发,一维TiO2则通过吸收紫外光形成电子-空穴对,并通过氧化还原反应实现污染物降解.同时,泡沫碳和TiO2的结合还使光热和光催化之间存在协同促进效应,光催化过程能抑制污染物沉积,促进光热水蒸发性能持续提升,光热效应又可加速光生电子-空穴对的分离和迁移,促进光催化降解.在太阳光照射下,最优体系CF@RT160在2.5h内使MB降解率达到74％,光热水蒸发率为0.89 kg·m-2·h-1,且经4次循环后,水蒸发率提升至 0.95 kg·m-2·h-1.
Abstract
Interfacial photothermal water evaporation is a very promising research technique for organic wastewater purification,but there is also the problem of organic pollutant deposition on the surface of the photothermal evaporator.In this paper,composite photothermal catalytic material(CF@RT)was prepared by introducing nano-TiO2 with photocatalytic effect into porous carbon foam photothermal absorber for simultaneous degradation of pollutants during photothermal wastewater evaporation.The structure and photothermal catalytic performance of this composite were analyzed.The results show that a large number of one-dimensional TiO2 nanorods with a diameter of about 10 nm were grown in CF@RT,and the nanorods were homogeneously dispersed on the surface of the carbon foam and in the pore structures.The introduction of TiO2 effectively broadens the range of the material's response to light,making the composite material dual-functional for photothermal and photocatalysis.Porous carbon foam evaporates water by absorbing visible-infrared light and converting it to heat,while one-dimensional TiO2 absorbs UV-visible light to form electron-hole pairs and degrades pollutants through redox eactions.Meanwhile,the combination of carbon foam and TiO2 also led to a synergistic promotional effect between photothermal and photocatalysis.The photocatalytic process inhibits pollutant deposition to promote the continuous enhancement of the evaporation performance of the photo-thermal conversion,and the photothermal effect accelerates the separation and migration of photogenerated electron-hole pairs to promote photocatalytic degradation.Under one solar irradiation,the MB degradation rate of the most effective CF@RT sample reached 74％in 2.5 h with a photothermal water evaporation rate of 0.89 kg·m-2·h-1.It is worth mentioning that the water evaporation of the composite evaporator has revealed a featured improvement up to 0.95 kg·m-2·h-1 after 4 cycles.
基金项目
国家自然科学基金(22105151)
国家自然科学基金(52305211)
湖北省重点研发计划项目(2022BAA094)
湖北省自然科学基金(2021CFB469)
湖北省自然科学基金(2022CFB626)
湖北省自然科学基金(2023AFB626)
湖北省教育厅科学技术研究项目(B2022017)
省部共建耐火材料与冶金国家重点实验室开放基金(G202407)
万方数据