Design Of Transition Metal Functionalized Boron And Nitrogen Co-doped Porous Carbon Nanomaterials And Their Hydrogen And Oxygen Catalytic Activit

Due to environmental issues and the rapid growth of global demand for renewable energy,there is an urgent need to explore environmentally friendly renewable energy sources to replace traditional fossil fuels.Hydrogen is widely considered as a potential energy source due to its advantages such as high energy density,low carbon dioxide emission,and ecological friendliness.Electrocatalytic cracking of water is considered to be a promising method for producing hydrogen and oxygen,which consists of two half reactions,namely hydrogen evolution reaction（HER）and oxygen evolution reaction（OER）.To date,the most advanced precious metal catalysts can guarantee considerable electrolytic water efficiency.However,the high price of precious metals and the bottleneck of natural rarity have resulted in the high price of hydrogen（H₂）production,which has greatly hindered the widespread application of water splitting.Non-noble metal metal catalysts developed based on transition metals[iron（Fe）,cobalt（Co）,nickel（Ni）]have been found to have efficient electrocatalytic properties.In addition,heteroatom doping can break the electroneuptality of carbon atoms and heteroatoms,thereby improving the electrocatalytic activity of carbon-based composites.Combined with the advantages of transition metal nanoparticles and boron（B）and nitrogen（N）co-doped carbon materials,we are committed to improving the catalytic activity of transition metal catalysts for hydrogen production from water electrocution.In this paper,three groups of transition metal based catalysts are designed and characterized physically and electrochemical.The novel three-dimensional（3D）cobalt（Co）nanoparticles（NPs）-embedded and ultrahigh B and N doped hierarchically porous carbon nanowires（denoted as Co@BNPCFs）have been successfully synthesized via pyrolyzing the 3D cobalt acetate/hydroxybenzeneboronic acid/polyvinylpyrrolidone precursor networks woven by electrospinning.For full water splitting,Co@BNPCFs-800 based electrolysis cell just requires a small voltage of 1.596 V to achieve 10 m A cm^-2,which is 19 m V smaller than that of the state-of-the-art 20 wt%Pt/C||Ru O₂benchmarkThe novel 3D ultrafine Ni NPs-embedded and B and N co-doped hierarchically porous carbon nanowires（denoted as Ni@BNPCFs）are successfully synthesized via pyrolysis of corresponding 3D nickel acetate[Ni（AC）₂·4H₂O]-hydroxybenzeneboronic acid（HBA）-polyvinylpyrrolidone（PVP）precursor networks woven by electrospinning.For full water splitting,the catalytic current density achieves 10 m A cm^-2at a low cell voltage of 1.584 V for the（-）Ni@BNPCFs-900||Ni@BNPCFs-900（+）electrolysis cell,which is 10 m V smaller than that of the（-）20 wt%Pt/C||Ru O₂（+）benchmark under the same conditions.The 3D hierarchically porous honeycomb-like material（denoted as FeNi@BNPCNS）are successfully synthesized via pyrolyzing the 3D Fe（AC）₂/Ni（AC）₂/HBBA/Melamine/PVP precursor networks.when the FeNi@BNPCNS-800 nanosheets were assembled on both cathode and anode of full water splitting cell,after optimizing the usagesofFeNi@BNPCNS-800nanosheets,theresultant（-）FeNi@BNPCNS-800||FeNi@BNPCNS-800（+）cell just required a small cell voltage of1.553 V to achieve a current density of 10 m A cm^-2,which was even 77 m V smaller than that of（-）20 wt%Pt/C||Ru O₂（+）cell.This work opens a new possibility for developing novel water-splitting devices based on transition metals.