Construction And Electrocatalytic Application Of Transition Metal Nitride Nanoarrays

In recent years,electrocatalyst technology has triggered intense research in the field of energy storage and conversion,due to the advantages of its high efficientcy and without the limit of time and space.The noble metal platinum(Pt)has shown the state-of-the-art performance in many electrocatalytic reactions,but the scarce reserve and high price limits its practical applications.Therefore,it is of great practical significance to design and develop non-noble metal-based electrocatalysts or low Pt content that are cost-efficiency and highly-efficient.Transition metal nitride(TMN),a type of interstitial compounds in which nitrogen typed into transition metals,usually exihibit many advantages,such as high conductivity,high corrosion resistance,high melting point and unique d-band electronic structures,which make transition metals nitrides can be used as a potential high-performance electrocatalyst or electrocatalyst carrier.In this thesis,starting from the design of transition metal nitride materials with nano-array structure,by adjusting the electronic structure of transition metal nitride to improve its intrinsic electrocatalytic activity,by regulating the strong interaction between transition metal nitride and Pt to develop high performance low Pt catalysts,the following studies were specifically carried out:1.Herein,we developed a new strategy to tune the intrinsic catalytic activity of molybdenum nitride(MoN)with metal cobalt(Co)by forming Co/MoN hetero-interface nanosheet array in situ,derived from the ammonia treatment strategy of bimetal oxide at low temperature.The presence of metallic Co can regulate the electronic structure of MoN,and increase the intrinsic catalytic activity of MoN.This hetero-interface electrocatalyst exhibits remarkable hydrogen evolution reaction(HER)activity(low overpotentials at 10,50,and 100 mA/cm~2 of 47,103,132 mV,respectively)and excellent stability with 70 h operation in 1.0 M KOH.The modulation of electronic structure of Mo N at the hetero-interface by Co,the best MoN-based HER electrocatalysts reported to date,and the enhanced water dissociation ability in alkaline media were verified both experimentally and theoretically.This work provides a simple method to in situ construction of hetero-interface,and has a good reference for the electrocatalytic application of related transition metal nitride materials.2.Herein,we used a simple method to construct a three-dimensional titanium nitride(TiN)nanowire array on carbon cloth,and then deposited ultra-trace Pt nanoparticles on it using atomic layer deposition(ALD)technology.The high corrosion resistance and high conductivity characteristics of the constructed three-dimensional TiN nanowire array,benefits from the excellent three-dimensional structure of the TiN carrier and the strong interaction between the carrier and the Pt nanoparticles make 10C-Pt/TiN/CC catalyst exhibits catalytic activity and stability superior to commercial Pt/C in methanol oxidation.In this work,the transition metal nitride nanowire array is used as a catalyst carrier,which reduces the loading of Pt and effectively improves the catalytic activity and stability of Pt,providing an effective strategy for the preparation of three-dimensional high-performance electrocatalysts.