Research On Multi-component Metal Nano-catalysts:Design,Synthesis And Synergistic Catalysis In Confined Space

The rapid development of global economy inevitably causes a series of serious problems,such as ecosystem degradation and pollution.In today’s environmental pollution problems,organic chemical pollutants do great harm to water,atmosphere and soil.In order to build a harmonious and stable natural environment,research on remediation of polluted water environment has been carried out continuously in various fields in recent years.The development of nanomaterials with confined structure creates a new opportunity for the field of environmental water purification.The research on the reaction mechanism of the confined effect contributes to a deeper understanding of the molecular characteristics and provides a new direction and impetus for the solution of environmental problems.The construction of nanoscale confined spatial structure provides a good platform to study the confined property of materials.In this paper,from the perspective of designing and developing nanomaterials with confined space structure,a one-dimensional confined structure catalyst represented by Fe2O3-Au@SiO2 nanoreactor with Yolk@Shell structure was prepared.The structure of the prepared Fe2O3-Au@SiO2 nanoreactor is coaxial hollow cable,with a diameter of about 120 nm.And the clearly arranged axial cores and loaded particles could be observed.The Fe2O3-Au@SiO2 nanoreactor has high photo-Fenton catalytic activity that the degradation reaction of 2-chlorophenol(2-CP)could reach 85%conversion rate in just 15 minutes under light eondition.Further,it is found that different synergistic components and contact modes have different influences on the catalytic effect through controlled experiments.Catalyst circulation experiments show that Fe2O3一Au@SiO2 nanoreactor has good catalytic stability.In the free radical masking experiment,it was found that the surface hydroxyl radical contributed the most to the catalytic oxidation.Through mechanism study,we confirmed that the presence of Au nanoparticles in the nanoscale confined space could promote the surface charge transfer of the axis core of iron oxide,so as to delay the binding of·OH and the electron-hole recombination,Thus,a higher concentration of.OH could be maintained in the Fe2O3-Au@SiO2 nanoreactor,prompting the catalyst showed higher activity in light fenton reaction.Meanwhile,the cavity between the SiO2 shell and the axis core of the Fe2O3 could enrich the reactant and increase its contact opportunity with the catalyst.This is also conducive to improving the performance of the catalyst.In the following research,we also innovated on the core components in the confined space.By introducing the ZnFe2O4/Fe2O3 heterojunction structure as the core,we attempted to construct a composite structure in which the heterojunction and confined space coexist.It’s benefit for us to investigate the application potentiality of nanoreactors.By means of experiment,characterization and theoretical calculation,this study comprehensively demonstrated the advance and high efficiency of confined structure nano-catalysts.The mechanism of the reaction process was revealed through verification in many aspects.The above research has opened up a vision for the field of environmental water purification.It’s also provided new ideas and pointed out the direction to the future for the field of catalytic synthesis.