Co 0.6Fe 2.4O4Self-assembly schematic of nanoblocks. The detection mechanism of As (III) was achieved by the adsorption of monolayers and the Fe / Fe (III) and Co (II)
Hefei Institute of Materia Medica, Chinese Academy of Sciences, Hefei Institute of Intelligent Machinery Huang research team using a surface with a large number of defects Co 0.6Fe 2.4O4Bulk nanomaterials achieve highly sensitive electrochemical detection of As (III), and detailed studies on the mechanism of the electrochemical behavior of enhanced surface defects have been performed.
The electrochemical behavior of nanomaterials depends largely on their intrinsic physicochemical properties, and the effective control of the structure and electronic state of the surface of nanomaterials is of great significance for the realization of good electrochemical detection behavior. On the surface of nanomaterials, The introduction of defects is considered to be an effective method to enhance the performance of nanomaterials, these surface defects can often serve as active sites to promote the adsorption and catalytic effect of nanomaterials.However, the impact of surface defects on the electrochemical detection of less research, The mechanism of enhancement is not clear, and the property that the nanomaterials are easy to agglomerate can seriously mask the active sites of the surface defects, which leads to the decrease of the detection performance of the nanomaterials and poses a great challenge to the enhancement mechanism of the surface defects.
In the previous work of the research group, the researchers adopted the TiO 2Doping oxygen vacancies on the surface to control the surface electronic structure of the (001) crystal plane of titania single crystal nanosheets, and using the electrochemical catalytic activity of oxygen-hole synergy to improve the electrochemical detection activity of the nanomaterials for heavy metal ions. , The researchers synthesized Co with a large number of surface defects 0.6Fe 2.4O4(~ 14nm) .In order to maximize the surface defect exposure, a self-assembly method was used to disperse the monolayer of nanoparticles on the electrode to construct a sensitive interface for the highly sensitive detection of As (III) XPS technology found that a large number of nano-block surface defects exist as active sites for adsorption, can effectively enhance the adsorption capacity of As (III) nanoparticles, thereby increasing As (III) enrichment on the electrode, increasing the electrochemical response signal In addition, the presence of defects can effectively increase the activity of Fe (II) and Co (II) on the surface of the nanoparticle, and effectively increase the redox reaction of As (III) with the intermediates of active electron mediator The rate of oxidation and reduction can be measured by the addition of Fe (II) and Co (II) ions during the detection of the effect of the cyclic adjustment of Fe (II) / (III) and Co (II) , And As (III) current increase. "The results show that the excellent electrochemical behavior of the nanoblocks is attributed to enhanced adsorption and redox cycling regulation of the surface defects. This study utilized large surface defects of nanomaterials to enhance Electrochemical performance of the method to build one With unique and sensitive interface, it is instructive to realize the analysis and detection of heavy metal ions.
Relevant research results published in the Journal of Analytical Chemistry.The research has been funded by the National Natural Science Foundation of China, the CAS innovation cross team, Hefei Research Institute, Dean Fund and other projects.
