Three-dimensional graphene/ carbon nano tube based molybdenum disulfide/cobaltous sulfide composite material electrocatalyst as well as preparation method and application thereof

Abstract

The invention belongs to the field of catalytic materials, and particularly relates to a three-dimensional graphene/ carbon nano tube based molybdenum disulfide/cobaltous sulfide composite material electrocatalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: step I, treating a precursor: performing ultrasonic treatment on a certainamount of oxidized graphene and a modified carbon nano tube, adding ascorbic acid, thiourea and a metal ion precursor to be uniformly mixed, wherein the metal ion precursor is sodium molybdate and cobalt chloride; step II, performing a hydrothermal reaction process: transferring mixed composite into a reaction kettle, heating the composite to a temperature of 160-200 DEG C, reacting for 20-28 hours at the temperature, conducting cooling to the room temperature to obtain a gel-like black substance, and conducting washing and freeze-drying to obtain a cylindrical black solid. A graphene/ carbonnano tube with a three-dimensional network structure provides a quick electron transfer path and an ion transport channel, and molybdenum disulfide/cobaltous sulfide with a nano structure is anchoredon three-dimensional structural carbon to expose more electro-active sites, so that electrochemical hydrogen evolution property is cooperatively improved.

Description

technical field [0001] The invention belongs to the field of catalytic materials, and in particular relates to a three-dimensional graphene / carbon nanotube-based molybdenum disulfide / cobalt sulfide composite electrocatalyst and its preparation method and application. Background technique [0002] Hydrogen is considered as a sustainable and clean energy. Water electrolysis is one of the effective ways to produce hydrogen. High-efficiency hydrogen evolution catalysts are often required in the process of water splitting reaction, so that the reaction can generate a larger current at a lower overvoltage. At present, Pt / C catalyst has the best hydrogen production performance in water electrolysis on the market, but due to its scarcity of resources and high cost, it cannot be applied on a large scale. Many researchers have tried to develop low-cost alternatives with similar activity to Pt. [0003] In recent years, some non-noble metals have been reported as hydrogen evolution ...

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Problems solved by technology

Patent CN104071744 discloses the use of electrospinning technology to prepare polymer fibers with core-shell structure containing molybdenum and cobalt, using sulfur powder as the sulfur source, controlling the annealing temperature, and synthesizing metal sulfide-based core-shell structure electrocatalytic materials to achieve 10 mA / cm 2 The overpotential required for the current density is reduced to 190 mV, and the performance improvement is mainly attributed to the complex cobalt compound changing the d-band electron density of the molybdenum atom, but the Tafel slope of the hydrogen evolution is still as high as 110 mV / Dec

Although these technologies have improved the hydrogen evolution activity of molybdenum sulfide to a certain extent, how to design and synthesize molybdenum sulfide-based catalysts with high catalytic activity is still one of the major challenges in this field.

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