BiOCl的制备、改性及其光催化性能的研究
发布时间：2018-10-30 07:57
【摘要】：随着人类社会的发展,环境污染已成为制约社会可持续发展的难题之一。光催化技术是利用太阳能,将污染物彻底降解,并且不产生二次污染的环保型污染处理方法,比传统的污染处理方式更具优势。BiOCl作为一种新型光催化剂,因其特殊层状结构而表现出的优异光催化性能,而成为近年研究的热点。然而BiOCl的禁带宽度较大,导致对太阳能的利用率低,限制了 BiOCl的应用。近些年来,有研究发现g-C3N4和BiOI具有较好的可见光催化性能,但由于制备工艺繁琐、成本较高以及低效率等原因,使其在生产应用中受到了限制。本文在水热合成优异紫外光催化性能的BiOCl基础上,采用超声法和水解-水热法分别合成了 g-C3N4/BiOCl和BiOI/BiOCl复合光催化剂,并系统研究了利用g-C3N4和BiOI半导体复合的方式来提升BiOCl光催化活性的机理。论文中首先采用水热法对BiOCl的合成工艺进行探索。结果表明,在水热条件为150℃、6h时,BiOCl的形貌为规则的片层状,且在紫外条件下对亚甲基蓝的降解率最大,1h内为79%。在此基础上,采用超声法合成具有不同质量比的g-C3N4/BiOCl复合催化剂。结果显示:用g-C3N4杂化BiOCl,可使g-C3N4/BiOCl复合催化剂具有可见光响应;当g-C3N4的质量为BiOCl的60%时,复合催化剂对亚甲基蓝的降解率最大;反应动力学常数k为0.0139 min-1,是纯g-C3N4的1.9倍。对其催化机理进行研究,发现由于光生电子-空穴对分离率的增加,使得复合催化剂具有提升的可见光活性。最后采用水解-水热法合成具有不同摩尔质量比BiOI/BiOCl复合光催化剂。结果显示:经BiOI的复合,可使BiOI/BiOCl复合光催化剂具有可见光响应;当I与C1的物质的量比为1:1时,复合催化剂对亚甲基蓝的降解率最大;反应动力学常数k为0.037 min-1,是纯BiOI的2.3倍。通过机理研究,由于存在BiOI/BiOCl异质结,可使光生电子-空穴对复合率降低,使复合催化剂具有提升的可见光活性。
[Abstract]:With the development of human society, environmental pollution has become one of the difficult problems restricting the sustainable development of society. Photocatalytic technology is an environmentally friendly pollution treatment method that uses solar energy to completely degrade pollutants and does not produce secondary pollution, which is superior to traditional pollution treatment methods. BiOCl is a new photocatalyst. Because of its special layered structure, its excellent photocatalytic performance has become a hot spot in recent years. However, the wide band gap of BiOCl leads to low utilization of solar energy, which limits the application of BiOCl. In recent years, some studies have found that g-C3N4 and BiOI have better visible light catalytic performance, but because of the tedious preparation process, high cost and low efficiency, they are limited in production and application. In this paper, based on the excellent UV photocatalytic properties of hydrothermal synthesis of BiOCl, g-C3N4/BiOCl and BiOI/BiOCl photocatalysts were synthesized by ultrasonic method and hydrolysis-hydrothermal method, respectively. The mechanism of improving the photocatalytic activity of BiOCl by using g-C3N4 and BiOI semiconductor composite was studied systematically. Firstly, hydrothermal method was used to explore the synthesis process of BiOCl. The results showed that the morphology of BiOCl was regular lamellar at 150 鈩，
本文编号：2299411
[Abstract]:With the development of human society, environmental pollution has become one of the difficult problems restricting the sustainable development of society. Photocatalytic technology is an environmentally friendly pollution treatment method that uses solar energy to completely degrade pollutants and does not produce secondary pollution, which is superior to traditional pollution treatment methods. BiOCl is a new photocatalyst. Because of its special layered structure, its excellent photocatalytic performance has become a hot spot in recent years. However, the wide band gap of BiOCl leads to low utilization of solar energy, which limits the application of BiOCl. In recent years, some studies have found that g-C3N4 and BiOI have better visible light catalytic performance, but because of the tedious preparation process, high cost and low efficiency, they are limited in production and application. In this paper, based on the excellent UV photocatalytic properties of hydrothermal synthesis of BiOCl, g-C3N4/BiOCl and BiOI/BiOCl photocatalysts were synthesized by ultrasonic method and hydrolysis-hydrothermal method, respectively. The mechanism of improving the photocatalytic activity of BiOCl by using g-C3N4 and BiOI semiconductor composite was studied systematically. Firstly, hydrothermal method was used to explore the synthesis process of BiOCl. The results showed that the morphology of BiOCl was regular lamellar at 150 鈩，
本文编号：2299411
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