Preparation Of Transition Metal Organic Gel Composites For Electrochemical Performance

The environmental dilapidate and pollution created by the consumption of non-renewable energy sources urgently need to explore and probe various split-new energy technologies to preserve our economy and society.Batteries,supercapacitors and water splitting are used as energy storage and conversion technologies have played an important role in reducing the use of fossil fuels,solving environmental problems,and the development of new electric vehicles.In this paper,three transition metal-based organogel composite materials were synthesized at room temperature,and their electrochemical energy storage and electrocatalytic oxygen evolution properties when used as electrode materials were studied.The main contents are as follows:（1）Self-assembled metal organic gel based on single metal ions(Ni²⁺and Mn²⁺)for supercapacitorsThe single metal gel Ni MOG composite material was successfully synthesized bythe self-assembly method.The metal ions coordinate with the carboxyl groups in the organic matter to form a porous structure,which makes the material have a higher specific capacitance.The ease of processing and fluidity of the gel highlight the application potential of the material.It can be seen that by testing its electrochemical performance,the material has good stability and rate performance(the current density is 6 A g^-1,and the specific capacitance is 67.9%of the initial capacitance),thereby providing an effective the new kind of synthetic SC electrode material.Furthermore,the assembled device of Ni MOG//AC could achieve the specific capacitance of 129.1F g^-1(under the current density of 1 A g^-1),and the energy density can reach 40.31 W h kg^-1at the power density is 186.76 W kg^-1.The Ni MOG composite material combines a simple,green experimental synthesis strategy,and has the potential to become a practical energy storage device.（2）The self-assembled bimetallic organic gel（Ni Mn MOG）for high-performance supercapacitorsThe conductive base bimetallic metal organic gel Ni Mn MOG with controllable morphology is manufactured through a self-assembly process using metal ions and a low molecular weight gelling agent.By changing the molar ratio of Ni²⁺and Mn²⁺,Ni Mn MOG with different nanostructures（such as blocks,wires and rods）can be synthesized under the interaction of metal ions and low molecular weight gelling agents.The Ni Mn MOG retains the higher specific capacitance(692.9 F g^-1under the current density of 1 A g^-1),perfect electrical conductivity(1.12 S cm^-1)and rate performance(516.6 F g^-1under the current density of 9 A g^-1).The assembled device of Ni Mn-3 MOG//AC electrode could supply the higher specific capacitance of 228.1F g^-1at 1 A g^-1,and the maximum energy density is 91.54 W h kg^-1under the power density is 850.03 W kg^-1.This work provides an effective synthesis strategy for electrode materials for practical energy storage and conversion applications.（3）Bimetallic organic gel based on Ni（II）and Fe（III）as an effective electrocatalyst for oxygen evolution reactionAt room temperature,the metal ions and the carboxyl groups in the organic ligands are coordinated to synthesize monometallic and bimetallic organogels,respectively.The formed bimetallic organic gel Fe_0.5Ni_0.5MOG has a network interconnected hollow tube structure,which has a large specific surface area and more reactive sites,which accelerates the efficiency of charge transfer,is conducive to the transfer of ionic charges,and is effective to increase the OER electrocatalytic performance.When Fe_0.5Ni_0.5MOG is used in OER electrocatalyst,it can reach an overpotential of 289 m V in 1 M KOH electrolyte solution.In addition,the low Tafel slope(99 m V dec^-1)of the Fe_0.5Ni_0.5MOG sample also verifies that the material has excellent electrocatalytic performance.Finally,after 1000 cycles of testing,the LSV curve of Fe_0.5Ni_0.5MOG has no obvious deviation from the original LSV curve,indicating that Fe_0.5Ni_0.5MOG has broad prospects when applied to electrocatalysts.