巯基功能化镁层状硅酸盐复合材料的构筑及其催化还原性能研究

Construction of thiol-functionalized magnesium phyllosilicate contained nanocomposite and investigation of its catalytic reduction performance

通过原位合成法将银纳米粒子和Fe_(3)O_(4)磁性纳米粒子负载于巯基功能化镁层状硅酸盐(MgSH)上,制备得到Fe_(3)O_(4)@MgSH/Ag纳米复合材料。通过SEM、XRD、FTIR等手段对复合材料进行了表征,并考察了Fe_(3)O_(4)@MgSH/Ag催化NaBH4还原4-硝基苯酚(4-NP)的性能。研究结果表明,Fe_(3)O_(4)@MgSH/Ag保留了巯基黏土具有的疏松多孔结构,且银纳米粒子和Fe_(3)O_(4)纳米粒子均匀负载于MgSH表面。通过动力学分析可知,Fe_(3)O_(4)@MgSH/Ag催化NaBH_(4)还原4-NP的反应遵循准一级反应动力学规律,其表观速率常数kapp为0.1608 min^(-1),并可在10 min内使溶液中0.5 mmol/L 4-NP的降解率达到98%以上,说明Fe_(3)O_(4)@MgSH/Ag具有高效的催化性能。此外,由于Fe3O4的存在,该材料还可通过磁性回收利用,经过6次重复使用后,4-NP的降解率仅变化了6%,说明Fe_(3)O_(4)@MgSH/Ag在催化还原4-NP中显示出了高效性和可循环使用性。

Fe_(3)O_(4)@MgSH/Ag nanocomposite was prepared via an in-situ synthetic route by loading the magnetic Fe_(3)O_(4) nanoparticles and Ag nanoparticles on thiol-functionalized magnesium phyllosilicate(MgSH).The SEM,XRD and FTIR were employed to investigate the morphology and structure of the nanocomposite,and its catalytic performance for the reduction of 4-nitrophenol(4-NP)was evaluated.The research results indicated that,Fe_(3)O_(4)@MgSH/Ag maintained the typical porous characters of thiol clay,and Ag and Fe_(3)O_(4) nanoparticles were uniformly loaded on the surface of MgSH.Through dynamic analysis,it could be concluded that,the catalyzed reduction of 4-NP by Fe_(3)O_(4)@MgSH/Ag followed quasi first-order reaction kinetics law,with an apparent rate constant kapp of 0.1608 min-1.It could achieve a degradation rate of over 98%for 0.5 mmol/L 4-NP in solution within 10 minutes,indicating that Fe_(3)O_(4)@MgSH/Ag had efficient catalytic performance.Furthermore,due to the presence of ferric oxide,Fe_(3)O_(4)@MgSH/Ag could also be recycled.Even after 6 times of repeated reactions,the degradation rate of 4-NP decreased only 6%,revealing Fe_(3)O_(4)@MgSH/Ag high catalytic efficiency and recyclability.