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以(010)晶面暴露的Bi2MoO6纳米片作为光催化剂,通过改变溶液pH值、催化剂用量及目标降解物的初始浓度等考察Bi2MoO6纳米片对土霉素(Oxytetracycline,OTC)和四环素(Tetracycline,TC)在可见光下降解效果的影响;通过加入不同的自由基清除剂来考察光催化过程的机理。结果表明:光催化剂对OTC和TC的降解效果会因其在溶液中的存在形式不同而改变,随着溶液pH值的升高OTC与TC会发生逐级电离。在最佳pH值(pH=11)条件下,可见光辐照1h后,OTC与TC分别降解42.1%和58.8%(催化剂质量浓度为1.4g/L)。OTC和TC的光催化降解动力学研究表明,其降解过程符合伪一级动力学方程,其降解动力学常数分别为0.006 64min-1和0.008 45min-1。光催化降解机理的研究表明,空穴是主要的活性物质,其原因可能是在pH值为11时,大量的OTC和TC被吸附在光催化剂表面,有利于光生电子从光催化剂迁移至目标降解物。
Bi2MoO6 nanosheets exposed on the (010) crystal plane were used as photocatalysts. The effects of Bi2MoO6 nanosheets on the biocompatibility of Oxytetracycline (OTC) and tetracycline (TC) were investigated by changing the pH of the solution, the amount of catalyst and the initial concentration of the target degradants. ) In the visible light degradation effect; by adding different free radical scavengers to examine the mechanism of photocatalytic process. The results showed that the photocatalytic degradation of OTC and TC would change due to the existence of different forms in the solution. As the pH value of the solution increased, OTC and TC would undergo stepwise ionization. At the optimum pH (pH = 11), OTC and TC degraded by 42.1% and 58.8% respectively after visible light irradiation for 1h (the catalyst mass concentration was 1.4g / L). The kinetic studies on the photocatalytic degradation of OTC and TC showed that the degradation process was in accordance with pseudo-first-order kinetic equation and the degradation kinetic constants were 0.006 64min-1 and 0.008 45min-1, respectively. The study of photocatalytic degradation mechanism shows that the hole is the main active material. The reason may be that at a pH of 11, a large amount of OTC and TC are adsorbed on the photocatalyst surface, which facilitates the migration of photogenerated electrons from the photocatalyst to the target Things.