Preparation Of Composite Electrode Based On Prussian Blue,Prussian Blue Analogues And Its Application In Electrocatalysis

Nowadays,with the rapid development of the economy,the development of clean energy and the detection of some small biomolecules have received more and more attention.Transition metal cyanide has the characteristics of wide material sources,simple preparation process and various kinds.It can be used as an ideal electrode material for electrochemical sensors and an excellent precursor for the preparation of corresponding metal-based nanomaterials.Based on this,an electrochemical sensor with Prussian blue?PB?as the main component was prepared and applied to the detection of ascorbic acid.Afterwards,we prepared cobalt selenide derived from Cobalt-based Prussian blue analogue?CoCo PBA?and used it on electrocatalyzing water oxidation.In addition,the exploration of the combination of novel technologies and Prussian blue analogous?PBAs?is also important in oxygen evolution reaction?OER?.In order to improve the catalytic effect of PBA in OER,the modified NiCoFe PBA was irradiated by O₂ plasma and Ar plasma respectively.1.A composite of molybdenum oxide and PB was prepared and loaded on the surface of graphite felt?GF?to construct?PB@MoO_x/GF?composite electrode,and then scanning electron microscope?SEM?,transmission electron microscope?TEM?,Fourier tansform infrared spectroscopy?FT-IR?,X-ray diffraction?XRD?,Element mapping analysis and X-ray photoelectron spectroscopy?XPS?and electrochemical methods were performed on the electrode materials.In addition,the synthesis process of PB promoted by molybdenum dioxide?MoO₂?nanorods was proved via UV-visible spectrophotometry.Finally,the PB@MoO_x/GF was used as a sensor to electrocatalytic detection of ascorbic acid,and it presents outstanding performance with an ultra-low detection limit,an excellent sensitivity as well as a good detection range,more importantly,the sensor can be extended for practical sample.2.Carbon-coated cobalt selenide nanoparticles(Co_0.85Se@C NPs)were obtained by direct selenization of CoCo PBA through one step solvothermal method for the first time.Subsequently,the selenide was investigated by means of SEM,TEM,XRD,Elemental mapping analysis,Energy Dispersive Spectrometer?EDS?,plasma emission spectroscopy?ICP-EMIS?,XPS and several electrochemical tests.Studies demonstrate that materials derived by CoCo PBA generate a lot of hollow structure,and could expose much more active sites for electrocatalysis,which synergizes with the unique composition of nonstoichiometric cobalt selenide to enhance the electrocatalytic performance in water oxidation.The Co_0.85Se@C NPs exhibits a lower overpotential and a smaller Tafel slope than CoCo PBA for OER with a current density of 10 mA cm^-2 in alkaline electrolyte.3.In order to enhance the oxygen evolution activity of PBAs,the ternary metal Prussian blue analogue?NiCoFe PBA?nanocube was synthesized by coprecipitation method and then irradiated via O₂ or Ar plasma.A series of characterizations such as SEM,TEM,FT-IR,XRD,EDS were carried out respectively.It is found that materials modified by the plasma maintain the structure and morphology of nano-framework from pristine NiCoFe PBA,but many surfaces become rougher.These changes make plasma-treated NiCoFe PBA show the elevated electrocatalytic activities,and the material obtained by Ar plasma treatment for 30 minutes has the optimal performance.