Study On Preparation And Electrocatalytic Performance Of 3D Tantalum Nitride Nano Films

With the rapid development of the global economy,the demand for energy is also expanding.However,the reserves of traditional fossil energy are gradually decreasing,and the use of fossil energy is accompanied by strong environmental pollution.Therefore,it is imperative to seek clean new energy to replace fossil energy and promote sustainable economic development.Electrocatalysis has attracted much attention as the most effective means of preparing new energy sources.Commercial noble metal catalysts such as Pt,Ru,Rh,etc.have high catalytic activity,but cannot be used on a large scale due to high cost and scarce reserves.Therefore,it is urgent to develop non-precious metal electrocatalysts with high reserves and low cost.Because of its low cost and electronic structure similar to the noble metal Pt,transition metal nitrides have the prospect of replacing noble metal catalysts for electrocatalysis.Based on this,we prepared 3D tantalum nitride nanofilms with limited growth a variety of highly active catalytic materials for electrocatalysis.The morphology and electrochemical performance of the catalyst were studied by various characterization methods.The specific content is as follows:(1)We synthesize tantalum oxide nano-films with limited growth of [Co(tzbc)2(H2O)4] complex through hydrothermal reaction.And use them as precursors for nitriding with ammonia to synthesize three-dimensional tantalum nitride nano-films with limited growth of cobalt nanoparticles wrapped by a nitrogen-doped carbon layer.Ta3N5@Co@C-800 shows excellent hydrogen evolution reaction performance in an acidic electrolyte,with an overpotential of 59 m V and a lower Tafel slope(58 m V.decade-1)at a current density of 10 m A.cm-2.For HER under alkaline conditions,Ta3N5@Co@C-800 has an overpotential of 93 m V and a lower Tafel slope(97 m V.decade-1),and it can run stably for 12 h at a current density of 10 m A.cm-2.For OER reactions,Ta3N5@Co@C-800 has an overpotential of 360 m V at a current density of 10 m A.cm-2 in 1 M KOH electrolyte,which is lower than the commercial Ru O2(η10 = 384 m V).According to the above-mentioned various characterization methods,it is known that cobalt nanoparticles are wrapped in a graphitized carbon layer,which improves its corrosion resistance.The limitation of cobalt nanoparticles to the three-dimensional tantalum nitride nanoporous film also improves its stability.The nano-tantalum nitride film and nitrogen-doped carbon-coated cobalt nanoparticles can work together for electrocatalysis.(2)We synthesize tantalum oxide nano-films with limited growth iron-nickel oxide nanoparticles through hydrothermal reaction.And use them as precursors for nitriding and reduction with hydrogen and ammonia to synthesize three-dimensional tantalum nitride nano-films with limited growth iron-nickel alloy nanoparticles.It exhibits excellent OER performance in 1M KOH electrolyte,the overpotential required to reach a current density of 10 m A/cm2 is 298 mv,the Tafel slope is 38.3 m V/dec,and it can run for a long time at this current density for 20 h.The above shows excellent electrochemical stability,far exceeding commercial ruthenium oxide.