UiO-66/氧化石墨烯的制备及对水中四氯化碳的吸附

Absorption of carbon tetrachloride from aqueous solution by synthesized UiO-66/graphene oxide

采用溶剂热法制备了UiO-66和UiO-66/氧化石墨烯复合材料;以水中四氯化碳为处理对象,研究了吸附时间、污染物浓度及温度等因素对吸附过程的影响,并对吸附过程进行动力学和热力学模拟探讨。结果表明,当四氯化碳浓度为10 mg·L^(-1)、30℃时,吸附反应在6 h达到平衡,四氯化碳的去除率为87.5%。UiO-66/氧化石墨烯材料对四氯化碳的吸附过程符合拟二级动力学模型。热力学结果显示ΔG<0、ΔH>0、ΔS>0,由此判断吸附过程是自发、吸热和熵增加的过程。UiO-66/氧化石墨烯材料中比表面积、表面分散力和晶体缺陷的增加使其对四氯化碳具有更好的吸附性能。

Nano-sized metal organic framework UiO-66 and UiO-66/graphene oxide composites were prepared using a microwave-assisted solvothermal method.Influences of several parameters,such as time,carbon tetrachloride concentration,and temperature,on the carbon tetrachloride adsorption by UiO-66/graphene oxide composites were investigated.Meanwhile,adsorption kinetics and thermodynamics were also explored.Results showed that the adsorption equilibrium occurred within 6 hours and the removal efficiency of carbon tetrachloride was 87.5%at its initial concentration of 10 mg·L-1 and 30℃.A pseudo-second order kinetic model fitted well with the adsorption kinetic process.The negative value ofΔG and positive values ofΔH andΔS determined through thermodynamics of adsorption indicated that the adsorption was a spontaneous,endothermic and entropy increase process.The adsorption effect of carbon tetrachloride on the UiO-66/GrO was better than UiO-66 owing to the increasing of specific area,dispersion forces and defects on the crystal surface.