阅读说明：本技术 一种硒化镍纳米片的制备方法及其应用 (Preparation method and application of nickel selenide nanosheet ) 是由 朱洋 芮黄平 肖紫滢 杨慧 刘苏莉 于 2019-11-07 设计创作，主要内容包括：本发明公开一种硒化镍纳米片的制备方法,所述方法为将乙酰丙酮镍溶液和含硒溶液进行升温反应得到硒化镍纳米片。本发明还公开了一种所述硒化镍纳米片作为燃料电池析氧反应催化剂的应用。本发明所得硒化镍纳米片应用于燃料电池析氧反应中,具有新型、高效、成本低的优点。(The invention discloses a preparation method of a nickel selenide nanosheet. The invention also discloses an application of the nickel selenide nanosheet as a catalyst for an oxygen evolution reaction of a fuel cell. The nickel selenide nanosheet provided by the invention is applied to the oxygen evolution reaction of the fuel cell, and has the advantages of being novel, efficient and low in cost.)

1. A preparation method of nickel selenide nanosheets is characterized by comprising the step of carrying out heating reaction on a nickel acetylacetonate solution and a selenium-containing solution to obtain the nickel selenide nanosheets.

2. The preparation method according to claim 1, wherein the method comprises the following specific operation steps: respectively dissolving nickel acetylacetonate and selenium powder in benzyl alcohol and octadecene, mixing, heating, reacting at constant temperature, and performing dispersion, sedimentation and centrifugal separation on reactants to obtain the nickel selenide nanosheet.

3. The preparation method as claimed in claim 2, wherein the reaction temperature is 230-270 ℃ and the reaction time is 1-5 h.

4. The method according to claim 2 or 3, wherein the isothermal reaction is carried out at a reaction temperature of 250 ℃ for a reaction time of 3 hours.

5. The method according to claim 2, wherein the rate of temperature rise is 3 to 10 ℃/min.

6. The preparation method according to claim 2, wherein the molar ratio of nickel acetylacetonate to selenium is 1: 2.

7. the method according to claim 2, wherein the dispersion sedimentation is performed using a mixed solution of n-heptane and absolute ethanol.

8. Use of nickel selenide nanosheets prepared by the preparation method of any one of claims 1-7 as a catalyst for an oxygen evolution reaction of a fuel cell.

Technical Field

The invention relates to the technical field of nano materials, in particular to a preparation method and application of nickel selenide nanosheets.

Background

As the supply of non-renewable fuels diminishes, there is an increasing concern regarding climate change, pollution and energy safety issues associated with them. However, most of the energy sources required by people are the sourceFrom traditional fossil fuels (coal, oil, and gas, etc.), these energy sources are unsustainable with limited reserves. Severe energy crisis and environmental pollution from fossil energy consumption are increasingly threatening the sustainable development of human society. Therefore, people are looking for clean energy and renewable resources. The core of clean energy is the need for advanced energy conversion systems such as water electrolysis, fuel cells, etc. The fuel cell has the characteristics of high energy efficiency, no noise, no pollution, continuous and stable operation and the like, and is considered as a new energy technology with the greatest development prospect in the 21 st century. General H₂-O₂The fuel cell and the hydrolysis cell are combined in a certain way to be circulated, namely to form renewable H₂-O₂A fuel cell. In a water electrolytic cell, adding H₂Feeding O into an electrolysis device, inputting into a computer, H₂Decomposition of O into H₂And O₂The method relates to anodic Oxygen Evolution Reaction (OER), and stores electric energy in a chemical energy mode. The theoretical voltage required for OER to occur at the anode was 1.23V. However, in the commercial water splitting system, the full splitting of water requires a voltage of 1.8-2.0V to drive the water splitting to generate clean energy. Therefore, the overpotential for water decomposition can be greatly reduced by using the catalyst for catalyzing water decomposition with high efficiency. Although IrO₂And RuO₂Is also the electrocatalyst with the best OER catalytic property at present, but has the defect of IrO₂And RuO₂The price is expensive, and the commercial application of the catalyst is further limited.

In the process of designing fuel cells, improving the reaction efficiency of Oxygen Evolution Reaction (OER) becomes the key for commercial applications. The key principle of designing the high-efficiency and durable oxygen evolution reaction electrocatalyst material lies in that: 1. a large number of active sites are present; 2. excellent conductivity; 3. stable catalytically active structure.

The literature researches show that OER needs multi-step electron transfer and transfer due to stronger O = O bond, so that the kinetics is slow, and the overpotential of the catalyst is too high. Therefore, lowering the overpotential of OER becomes a key for commercial applications in designing fuel cells. The current development of nanotechnology gives new renewable H types₂-O₂The design of fuel cell electrocatalysts brings new opportunities. Over the past few years, scientists have also been working on developing nanocatalysts with high performance, high selectivity, high stability and low cost. Meanwhile, the induced selective growth of one or more metals at the structural defect is introduced, so that the regulation and control of the surface geometrical structure and the electronic structure of the multi-component metal nanocrystalline are further promoted, and a larger space is provided for optimizing the catalytic reaction. For example, the core-shell Au @ CoFeOx controllably synthesized by the Strickler problem group has the advantages that the catalytic activity and the temperature property of the catalyst are improved due to the coupling effect between Au and metal oxide, the electrochemical test surface is formed by taking OER as a probe reaction for Au and metal oxide nanocrystals (Au @ MxOy, M = Ni, Co, Fe and CoFe).

Therefore, research and development of high-efficiency multi-element nanocrystalline catalysts are the current research hotspots; in the development process of renewable energy technology, the search for efficient, cheap and specially-structured alloy nanocrystals, in particular for electrocatalysts applicable to OER, is of great significance and challenge.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a preparation method of nickel selenide nanosheets aiming at the defects in the prior art, and the obtained nickel selenide nanosheets are applied to the oxygen evolution reaction of a fuel cell and have the advantages of being novel, efficient and low in cost.

The technical scheme is as follows: the invention relates to a preparation method of a nickel selenide nanosheet.

Preferably, the method comprises the following specific operation steps: respectively dissolving nickel acetylacetonate and selenium powder in benzyl alcohol and octadecene, mixing, heating, carrying out constant-temperature sand bath reaction, and carrying out dispersion sedimentation and centrifugal separation on reactants to obtain the nickel selenide nanosheet.

Preferably, in the constant-temperature reaction, the reaction temperature is 230-270 ℃, and the reaction time is 1-5 h.

Preferably, in the isothermal reaction, the reaction temperature is 250 ℃ and the reaction time is 3 hours.

Preferably, the rate of temperature rise is 3-10 ℃/min.

Preferably, the molar ratio of the nickel acetylacetonate to the selenium is 1: 2.

preferably, in the dispersion sedimentation, the dispersion sedimentation is performed by using a mixed solution of n-heptane and absolute ethanol.

The invention also discloses an application of the nickel selenide nanosheet prepared by the preparation method as a fuel cell oxygen evolution reaction catalyst.

Compared with the prior art, the invention has the beneficial effects that: the prepared flint nano-sheet has excellent oxygen evolution performance, can efficiently catalyze the oxygen evolution reaction in a fuel cell, and has detection performance superior to that of the currently marketed IrO₂Has important guiding significance for the technical development of renewable energy sources. In addition, the nickel selenide nanosheets related by the invention are prepared by solid-liquid phase chemical reaction, the nickel selenide nanosheets are controllably synthesized at normal pressure and low temperature, and meanwhile, the nickel selenide nanosheets are obtained by adopting a 'hydrothermal solvent method' mode and a sand bath program temperature control mode, so that the process is simple, the reaction temperature is low, the yield is high, and the method is suitable for batch production.

Drawings

Fig. 1 is an XRD pattern of nickel selenide nanosheets in example 1 of the present invention.

Fig. 2 is a TEM image of nickel selenide nanosheets in example 1 of the present invention.

Fig. 3 is an OER performance test chart of nickel selenide nanosheets in example 1 of the present invention.

Detailed Description

The technical solution of the present invention is described in detail below with reference to specific examples and drawings, but the scope of the present invention is not limited to the examples.