Yang Haowei, Fan Jinlong, Zhou Chengxin, Luo Rui, Liu Hongwei, Wan Yingfei, Zhang Jin, Chen Jinwei, Wang Gang, Wang Ruilin, Jiang Chunping
College of Materials Science and Engineering, Sichuan University, Chengdu 610065, P. R. China.
West China School of Public Health No. 4 West China Teaching Hospital, Sichuan University, Chengdu 610041, P. R. China.
ACS Omega. 2020 Jul 7;5(28):17160-17169. doi: 10.1021/acsomega.0c01131. eCollection 2020 Jul 21.
The CoO@CdS double-layered hollow spheres were first prepared by the template-removal method with the assistance of the ZIF-67 material; the structure has been proved by transmission electron microscopy (TEM). The CoO@CdS hollow spheres calcinated at 400 °C exhibited the highest photodegradation activity. Nearly 90% phenol was degraded after 2 h of visible-light irradiation. More than 80% rhodamine-B (RhB) was degraded within the first 30 min and nearly eliminated after 1 h of irradiation. The mechanism of the photodegradation reaction was investigated. Based on the analysis of electron spin resonance (ESR) spectra and radical trapping test, it was found that superoxide radicals are the major oxidative species for dye degradation and holes and hydroxyl radicals are the major oxidative species for phenol degradation. These results may be used in industrial wastewater treatment. The reaction obeys first-order reaction kinetics, and the rate constant of the CoO@CdS hollow sphere in dye degradation is 0.05 min and that in phenol degradation is 0.02 min, which is three times higher than that of CdS nanoparticles. These results indicated the high oxidizing ability of the samples.
首先通过模板去除法并借助ZIF-67材料制备了CoO@CdS双层空心球；其结构已通过透射电子显微镜（TEM）得到证实。在400℃煅烧的CoO@CdS空心球表现出最高的光降解活性。可见光照射2小时后，近90%的苯酚被降解。在照射的前30分钟内，超过80%的罗丹明B（RhB）被降解，照射1小时后几乎被完全去除。对光降解反应的机理进行了研究。基于电子自旋共振（ESR）光谱分析和自由基捕获试验，发现超氧自由基是染料降解的主要氧化物种，而空穴和羟基自由基是苯酚降解的主要氧化物种。这些结果可用于工业废水处理。该反应符合一级反应动力学，CoO@CdS空心球在染料降解中的速率常数为0.05 min，在苯酚降解中的速率常数为0.02 min，这比CdS纳米颗粒高出三倍。这些结果表明了样品的高氧化能力。
