Controllable Preparation Of Ferrous Series Metal Phosphide-based Functional Nano Materials And Their Applications

With the constant consumption of non-renewable resources and increasingly deteriorated environment problem,research on clean,efficient and earth-abundant new energy has drawn great attention all over the world.During the last decades,transition metal phosphides have been reported as multifunctional materials owing to their unique physicochemical properties,such as in the field of lithium-ion battery materials,electrocatalysts,micro-electronics and biomedical science.Though great achievement has been made in preparation and application of transition metal phosphides,it remains a big challenge in the following aspects:1)how to realize the macro-quantity preparation,2)expanding the transition metal phosphides from binary system to ternary system,3)enhancing the performance of the transition metal phosphides nano-materials.Above-mentioned issues are the focuses for researchers now.In this work,we mainly studied above-mentioned challenges and materials applied in lithium-ion batteries,electrocatalysis and supercapacitor fields.The main parts of the results are provided as follows:1.Designed a kind of facile method for macro-quantity preparation of transition metal phosphides,and studied its catalytic performance in hydrogen evolution reaction.We used acetylacetone-based metallic compound and triphenylphosphine as raw materials and successfully obtained carbon coated cobalt phosphide nanomaterial.We applied it as catalyst in HER progress and illustrated carbon as an important part and play decisive role.Additionally,the preparation method in this chapter is also suitable for other phosphide materials.2.We develop a facile and controllable one-step solvothermal method to synthesize Ni₁₂P₅ nanoparticles,and further obtained a new kind of unique hybrid nanostructures by direct in situ growth of Ni₁₂P₅ nanocrystals onto oxidized multiwall carbon nanotubes(Ni₁₂P₅/CNTs nanohybrids).The effects of reaction solvent on the prepared nanocrystals have been investigated.In addition,the performance of lithium ion storage and HER catalytic of the Ni₁₂P₅/CNTs nanohybrids have been explored and electrochemical measurements suggest that the Ni₁₂P₅/CNTs nanohybrids exhibits excellent performance and stability.3.Monodisperse ternary NiCoP nanoparticles with high-quality have been fabricated via a facile and soft one-step solvothermal method.The XRD,TEM test shows that the as-prepared NiCoP nanoparticles were hexagonal phase and with average particle size of 8.5 nm.Furthermore,we studied the overall water splitting performance of NiCoP under different test systems.And the results show that NiCoP material has excellent HER catalytic property in acid medium,which exceeds to most reported non-noble HER catalysts.Also,as-obtained NiCoP materials can also use as both HER and OER catalysts in alkaline system.Therefore,we used it as bi-functional catalysts for overall water splitting and showed satisfied results.Meanwhile,based on the same synthetic route,other ternary phosphides are also obtained.4.Based on a kind of solution-phase self-assembly strategy to attached NiCoP nanoparticles onto the surface of graphene,we obtained a type of unique quasi-plane structured NiCoP/G nanocomposites.The NiCoP catalyst in small-size wrapped by graphene could afford more catalytic active sites,enhance electronic transmission process and effectively buffer the volume change during the lithium-ion batteries cyclical process.Compared with single NiCoP materials,the NiCoP/G nanocomposites present more outstanding electrochemical activity and stability.