Study On Electrochemical Detection Of Heavy Metal Ions In Water Using Zirconium-based Nanomaterials

With the continuous improvement of industrialization and productivity of society,the toxic pollutants brought with it also threaten human health at all times.Among them,the safety of the water environment is particularly important,so a series of technical methods are needed to analyze the content of harmful substances in water,including the detection of heavy metal ions.Among the existing detection methods,electrochemical methods have been favored for convenience,economy,and high detection efficiency.In the field of electrochemical detection of heavy metal ions,it has always been the focus of research to find materials with both sensitive interfaces and high electrical conductivity.Although a variety of materials have achieved good performance at present,due to the incomplete detection mechanism,materials with more efficient reaction mechanisms need to be used.In addition,compared with the application of finding new materials,exploring the relationship between the intrinsic properties of materials and electrochemical behavior is more helpful for us to understand the mystery of the electrochemical detection process.In this subject,zirconium-based nanomaterials were selected as electrode-sensitive materials,and zirconium-based nanomaterials containing doping and different oxygen vacancy concentrations were fabricated.The intrinsic relationship between different physical properties and electrochemical behaviors of these materials was studied.The main tasks are as follows:(1)ZrO2 and Zr2ON2 with similar morphology were successfully prepared,and they were characterized to some extent.After modifying them on a glassy carbon electrode with Hg(II)as the target ion and comparing their respective sensitivities,it was found that the electrochemical performance of Zr2ON2 after N-doping was obviously due to ZrO2.(2)ZrO2 with certain oxygen vacancies was synthesized by hydrothermal method,and it was calcined in a tube furnace with air or H2/Ar gas,respectively,and three kinds of ZrO2 were obtained.Electron paramagnetic resonance(EPR)proved that the three ZrO2 had different oxygen vacancy concentrations,and found that there was a large difference in their sensitivity to electrochemical detection of Pb(II).X-ray photoelectron spectroscopy(XPS),infrared spectroscopy(FT-IR),zeta potentiometer and ultraviolet-visible absorption spectrometer(UV-VIS),were used to determine the proportion of different types of oxygen vacancies,band gap energy,and-OH content in ZrO2.And electronegativity.These data show that the excellent electrochemical performance comes from the adsorption of oxygen vacancies and surface-OH,and combined with the synergistic effect of superoxide radicals,thereby improving the electrocatalytic ability.Oxygen vacancies introduce a new density state in the material,and its concentration change also changes the energy band gap.These findings further study the issue of improving the low conductivity and catalytic activity of semiconductors,and provide guidance for the development of other electrocatalytic supersensitive materials.