不同形貌Co_(3)O_(4)的制备及其活化过一硫酸盐降解亚甲基蓝的性能  

Co_(3)O_(4)with Different Morphologies:Synthesis and Performances in Activating Peroxymonosulfate for Methylene Blue Degradation

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)

机构地区：[1]重庆理工大学化学化工学院,重庆400054 [2]中国兵器工业集团第五二研究所,包头014000

出　　处：《无机化学学报》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。

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.

关 键 词：高级氧化技术 Co_(3)O_(4) 过一硫酸盐 表面羟基 亚甲基蓝 

分 类 号：X131.2[环境科学与工程—环境科学] O614.812[理学—无机化学]