The Preparation Of Carbon Fiber Loaded With Transition Sulfide Compounds And Their Hydrogen Evolution Reaction Performance

The development of clean and renewable energy sources holds the promise for the solution of environmental contamination and energy crisis.Hydrogen has been recognized as the center of newly emerged hydrogen economy for replacing oil fuels due to its clean and sustainable features.The electrochemical splitting of water is a feasible and efficient method for large-scale production of hydrogen.Among of the various electrocatalysts,two-dimension transition metal dichalcogenides?TMDs?have attracted wide attention benefiting from the graphene-like layer structure and novel electronic structure,since catalytic activity related to the exposed edge sites is confirmed by theory and experiment.However,the low inherent conductivity and poor stability seriously hinder its practical application.In view of this,utilization of conductive carbon-based materials loaded with TMDs is a promising strategy to fabricate highly active catalysis with excellent stability via hydrothermal and chemical vapor deposition method.Finally,we further explored the internal action between morphology and catalytic activity.The catalytic activity of MoS₂ is located at the edge sites of layer,so it is crucial to construct more active edge sites.The MoS₂ nanostructures are grown on carbon nanofibers?CNFs?,which the morphologies can be controlled by adjusting precursor ratio via hydrothermal method.The results indicate that increased precursor ratio can significantly expose more active edge sits resulting in enhancing catalytic activity?lowering onset overpotential and improving current density?.Additionally,the well crystallization of catalysts and flexible CNFs substrate are the two key factors which catalysts can avoid dissolution in acid solutions for the long-term application.Incorporating N/Co dual dopant into WS₂ ultra-thin sheets is an efficient strategy to expose mass active sites leading to promote HER activity.The highly conductive CNFs not only serve as self-support substrates but also provide a convenient pathway for facilitating electron transport in order to enhance performance of catalysts.The incorporation of Co dopant lowers the hydrogen adsorption free energy and arouses more active sites resulting from the formation of Co-S cluster.The presence of conductive N plays an important role to enhance the intrinsic conductivity of catalysts while the WS₂ ultra-thin sheets offer a strong framework for stabilizing Co-S cluster and tuning HER activity,avoiding dissolution in acid solution.Hence,developing an effective and all-in-one way for enhancing conductivity and stability is valuable and desirable.To further protect internal catalysts from corrosion or oxidation by electrolyte,we fabricate N-doped carbon shell protecting one-dimensional NiCo Se_2-x nanorods.The NiCoSe_2-x nanorod electrode exhibits excellent catalytic activity towards HER and OER due to the unsaturated Se atom resulting in exposing mass active sites.Meanwhile,the presence of carbon shell functions as protect layer and constructs a pathway for facilitating electron transport leading to promote catalytic activity.Furthermore,the NiCoSe_2-x electrode can be simultaneously served as bifunctional catalysts for electrochemical splitting of water in alkaline electrolyte.