In Situ Growth And Electrochemical Water Splitting On Iron Compounds/foam Metal

Presently,the rapid growth of fossil fuel depletion has caused not only the energy crisis but also the inevitable associated environmental issues,in particular,global warming and haze.For this reason,unflagging efforts have been devoted to the exploitation and utilization of renewable and clean energy sources.With this regard,hydrogen can be considered as an ideal clean,high-efficient and renewable energy source.Thus far,the hydrogen evolution reaction?HER?and oxygen evolution reaction?OER?of electrocatalytic water splitting plays the most effective and sustainable hydrogen production technology,in which electrocatalysts mainly based on noble metal Pt and RuO₂.Although Pt-based catalysts exhibit excellent energy transfer efficiency with low overpotential and low Tafel slop,the scarce and expensive nature of precious metals could severely hamper their practical utilization,accompany by the unideal activity and stability.Therefore,it is still a challenge to develop a high-performance and low-cost catalysts towards HER and OER.Based on the above analyses,we used the in-situ growth strategy to synthesize iron series compounds?sulfides,phosphides and nitrides?on the foam metal?nickel foam,copper foam?.It has the advantages of long-short and high electrical conductivity,which can provide ion transport channel,resulting in well HER and OER electrocatalytic activities for HER and OER.The content of this thesis is divided into the followed three parts:1.A facile one-step solvothermal strategy had been used for controllable constructing the homojunction structures of Ni₃S₂ nanosheets in-situ epitaxially grown on nanorods by using Ni foam as self-support substrate and nickel resource?Ni₃S₂/NF?.The special 3 D Ni₃S₂ nanorods@nanosheets homojunction could provide plentiful catalytically active sites,meanwhile,the intimate contact between Ni₃S₂ and Ni foam could enhance the long-term stability.The inevitable sulfur vacancies in the Ni₃S₂could tune electronic structure of the surface and enhance the catalytic activity.The synergistic effect leads to the as-prepared Ni₃S₂/NF exhibits a superior HER performance,low Tafel slope and excellent long-term stability.2.The NiCo₂O₄/NF@NC was firstly synthesized by using N-doped carbon coated nickel foam as the support via a hydrothermal route.Then,a phosphorization process as adopted to prepare NiCoP/NF@NC composite.As a bifunctional electrocatalyst for HER and OER,the resulting NiCoP/NF@NC exhibited a similar onset potential as the Pt/C and RuO₂ commercial catalysts.Simultaneously,it also showed a lower Tafel slope,and better long-term stability.3.A hydrothermal method combined a subsequent nitridation process was used for synthesis of Ni N and CoN composites on the carbon coated copper foam to obtain NiCo/CF@NC.The special 3 D structure exhibited good electrocatalytic activities for both HER and OER in alkaline electrolyte.It also exhibited well water splitting performance and cyclic stability.