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光催化技术是一种将太阳能转化为化学能的绿色技术,在污染治理和能源生产方面有广阔的应用前景。近几年,碳酸氧铋光催化剂因其优异的光催化性能受到广泛关注,但因其只对紫外光具有响应和回收利用困难等问题限制了在实际生产中的应用。对碳酸氧铋进行形貌控制和改性能有效改善其光催化性能,介绍零维、一维、二维和三维结构的碳酸氧铋光催化剂的研究现状,指出三维结构的碳酸氧铋展现更佳的光催化性能。综述了采用掺杂、金属沉积和构建异质结方式对碳酸氧铋进行改性所取得的进展,提出碳酸氧铋光催化剂在降解机理、降解对象和降解环境等方面需不断努力深入研究。 相似文献
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具有可见光响应的V-TiO2/AC光催化剂的制备 总被引:1,自引:1,他引:0
采用水热法在温和条件下制备了V掺杂的TiO2/活性炭(AC)光催化剂.利用XRD、SEM、漫反射、红外及荧光光谱对催化剂的物化性质进行了表征.结果显示,V-TiO2仍保持了锐钛矿相,没有出现V的衍射峰.相比纯TiO2,经过V掺杂的样品,具有较高的表面羟基密度,较低的栽流子复合几率,同时吸收光谱向可见光区移动.将纳米级的V-TiO2沉积在AC上可形成微-纳结构.在可见光照射下,V-TiO2/AC催化降解4-氯苯酚的能力高于纯V-TiO2和P25,这可归因于V的掺杂和AC协同作用的结果. 相似文献
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Novel visible light magnetically separable graphene-based BiOBr composite photocatalysts were prepared for the first time. The structures, morphologies and optical properties were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction and ultravioletvisible spectroscopy, respectively. The photocatalytic activity of the resulting samples was evaluated by degradation of tetracycline under visible light irradiation. An appropriate amount of introduced graphene can significantly enhance the photocatalytic activities. The enhanced activities were mainly attributed to the enhanced light absorption and the interfacial transfer of electrons. The corresponding photocatalytic mechanism was proposed based on the results. 相似文献
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The artificial ecological floating bed is widely used in rivers and lakes to repair and purify polluted water. However, the water flow pattern and the water level distribution are significantly changed by the floating beds, and the influence on the water flow is different from that of aquatic plants. In this paper, based on the continuous porous media model, a moveable two-layer combination model is built to describe the floating bed. The influences of the floating beds on the water flow characteristics are studied by numerical simulations and experiments using an experimental water channel. The variations of the water level distribution are discussed under conditions of different flow velocities( v= 0.1 m/s, 0.2 m/s, 0.30 m/s, 0.4 m/s), floating bed coverage rates(20%, 40%, 60%) and arrangement positions away from the channel wall( D= 0 m, 0.1 m, 0.2 m). The results indicate that the flow velocity increases under the floating beds, and the water level rises significantly under high flow velocity conditions in the upstream region and the floating bed region. In addition, the average rising water level value(ARWLV) increases significantly with the increase of the floating bed coverage rate, and the arrangement position of floating beds in the river can also greatly influence the water level distribution under a high-flow velocity condition(v ?0.2 m /s). 相似文献
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为探究当前环境流量的研究进展及发展方向,补充环境流量评估方面的研究方法,概述了国内外环境流量研究进展,应用CiteSpace软件结合中国知网与Web of Science数据库分析环境流量研究方法在21世纪以来的历史热点及主题演变情况。从开发背景、模型模块及应用步骤等方面详细介绍了一种用于环境流量评估的整体法——下游河道对流量变化响应法DRIFT(Downstream Response to Imposed Flow Transformation),结合南非奥卡万戈河以及赞比西河工程案例总结了该方法在环境流量评估及生态系统保护研究方面的应用,为环境流量研究提供新的思路与方法。 相似文献
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