摘要
分别采用尿素水热-煅烧法、化学浴沉积-煅烧法和草酸盐热解法制备出具有不同形貌的Co_(3)O_(4)(Co_(3)O_(4)-A、Co_(3)O_(4)-B和Co_(3)O_(4)-C)粉体材料,对比了它们作为催化剂活化过一硫酸盐(PMS)降解亚甲基蓝(MB)的性能。结果表明,3种Co_(3)O_(4)材料均具有分级微/纳米结构,形貌分别呈绒球状、无规则颗粒状和纤维状。PMS在3种催化剂作用下的分解过程均符合一级反应动力学模型,反应速率常数依次为0.0471、0.2174和0.0037 min^(-1)。无规则颗粒状Co_(3)O_(4)-B表现出最高的PMS活化性能,是其具有最大比表面积、最高表面氧空位浓度以及表面羟基密度综合作用的结果。在催化剂用量0.02 g·L^(-1)、PMS投加量0.6 mmol·L^(-1)的工艺参数条件下,Co_(3)O_(4)-B/PMS高级氧化体系在25 min内对MB的降解即可达98.33%。电子顺磁共振测试证实Co_(3)O_(4)-B/PMS高级氧化体系中存在·SO_(4)^(-)、·OH、·O_(2)^(-)和^(1)O_(2)四种活性氧物种,基于此提出了Co_(3)O_(4)-B活化PMS及降解MB的反应机理。
Three methods(urea hydrothermal-calcination,chemical bath deposition-calcination,and oxalate pyrolysis)were used to prepare Co_(3)O_(4)powder materials with different morphologies,which were named Co_(3)O_(4)-A,Co_(3)O_(4)-B,and Co_(3)O_(4)-C,respectively.All of them were taken as catalysts to activate peroxymonosulfate(PMS)for the degradation of methylene blue(MB).It is found that these Co_(3)O_(4)materials were quite different in their catalytic performance.Under the assistance of Co_(3)O_(4)-A,Co_(3)O_(4)-B,and Co_(3)O_(4)-C,the PMS decomposition reaction rate constants were measured as 0.0471,0.2174,and 0.0037 min^(-1),while the degradation ratios of MB were 91.25%(reaction time:50min),100.00%(reaction time:25 min),and 31.55%(reaction time:50 min),respectively.That is,Co_(3)O_(4)-B had the best catalytic performance.To make clear the difference in the catalytic ability of Co_(3)O_(4),a series of characterizations were carried out.It is discovered that these Co_(3)O_(4)materials are different in many ways such as crystallinity,microstructure,specific surface area,surface oxygen vacancy concentration,and surface hydroxyl density.And it is confirmed that the primary factor influencing the catalytic performance of Co_(3)O_(4)is the surface hydroxyl density.In addition,the optimized parameters for MB degradation in the Co_(3)O_(4)-B/PMS reaction system were determined as follows:reaction temperature 25℃,catalyst dosage 0.02 g·L^(-1),and PMS dosage 0.6 mmol·L^(-1),where the MB degradation ratio was as high as 98.33%.Moreover,the reactive oxygen species·SO_(4)^(-),·OH,·O_(2)^(-)and ^(1)O_(2)were all detected in the Co_(3)O_(4)-B/PMS system according to the quenching experiments and electron paramagnetic resonance tests,and sulfate radicals were identified as the primary reactive oxygen species.
作者
夏强
廖小刚
沈海丽
郑林
李纲
田甜
XIA Qiang;LIAO Xiao-Gang;SHEN Hai-Li;ZHENG Lin;LI Gang;TIAN Tian(College of Chemistry and Chemical Engineering,Chongqing University of Technology,Chongqing 400054,China;52 Institute of China North Industries Group,Baotou,Inner Mongolia 014000,China)
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2022年第11期2191-2201,共11页
Chinese Journal of Inorganic Chemistry
基金
重庆市教委科技项目(No.KJQN202101102)
重庆理工大学科研项目(No.clgycx 20203085,gzlcx20223170,gzlcx20223160)资助。