A three-dimensional graphene/carbon nanotube-based molybdenum disulfide/cobalt sulfide composite electrocatalyst and its preparation method and application

Abstract

The invention belongs to the field of catalytic materials, in particular to a three-dimensional graphene / carbon nanotube-based molybdenum disulfide / cobalt sulfide composite material electrocatalyst and its preparation method and application, comprising the following steps: Step 1: Precursor treatment: certain After a certain amount of graphene oxide and modified carbon nanotubes are ultrasonicated, add ascorbic acid, thiourea and metal ion precursors and mix evenly, and the metal ion precursors are sodium molybdate and cobalt chloride; Step 2: hydrothermal reaction process: the The mixed complex was transferred to a reaction kettle, heated to 160-200°C, and reacted at this temperature for 20-28h. After cooling to room temperature, a gel-like black substance was obtained, which was washed and lyophilized to obtain a columnar black solid. The three-dimensional network structure of graphene / carbon nanotubes provides fast electron transfer paths and ion transport channels, and the nanostructured molybdenum disulfide / cobalt sulfide anchors on the three-dimensional carbon structure to expose more electroactive sites, thereby synergistically enhancing the electrical Chemical hydrogen evolution performance.

Description

technical field [0001] The invention belongs to the field of catalytic materials, in particular 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 catalysts, s...

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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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