Cdot (at) Ni2P composite electro-catalysis hydrogen production material and preparation method thereof

Abstract

The invention provides a Cdot (at) Ni2P composite electro-catalysis hydrogen production material and a preparation method of the Cdot (at) Ni2P composite electro-catalysis hydrogen production material. The preparation method comprises the following steps: firstly, fully compounding carbon quantum dots with nickel chloride, and then roasting sodium hypophosphite and the compound to obtain the Cdot-coated Ni2P composite electrocatalytic hydrogen production material. Compared with the prior art, the preparation method has the biggest characteristics that a novel catalyst applied to the field of electro-catalytic hydrogen production is simple and efficient in preparation process, and the prepared Cot-coated Ni2P composite electro-catalytic hydrogen production material is good in performance and perfect in crystal structure, has high catalytic hydrogen production performance and excellent recycling performance and is easy to recycle.

Description

Technical Field

[0001] The present invention relates to the technical field of electrocatalytic hydrogen production materials, and particularly relates to a Cdot@Ni2P composite electrocatalytic hydrogen production material and a preparation method thereof. Background Art

[0002] Electrochemical decomposition of water to produce hydrogen using a catalyst is an effective way to realize the efficient utilization of hydrogen energy, alleviate the current serious environmental problems and energy crisis. However, there are still many limitations in this technology at present, such as low conversion efficiency and high application cost. Designing and synthesizing electrocatalysts with high activity, low cost and high stability is the key to solving these problems. Phosphide is a transition metal, which is a new type of catalytic material after nitrides and carbides, such as WMoP, Ni2P, etc. Their physical properties are similar to those of nitrides and carbides, but phosphides have better sulfur resistance, anti-carbon deposition and anti-poisoning properties. Research shows that the Ni2P catalyst has excellent activity and stability among transition metal phosphides. At present, under the trend of environmental protection requirements of low sulfur, low nitrogen and low chlorine, the Ni2P catalyst has a wide application prospect, and Cdot (carbon quantum dots) has many advantages such as good water solubility, low toxicity, environmental friendliness, wide raw material sources and low cost. Element doping is a common means of introducing defects into Ni2P and is also one of the most widely used modification technologies at present. However, the preparation methods in current research have harsh preparation conditions, relatively complex process conditions, low yield of the prepared catalyst, difficult recycling, and impurities will be introduced into the catalyst after the reaction, reducing the purity. Summary of the Invention

[0003] The present invention incorporates Cdot (carbon quantum dots) into the synthesis of Ni2P to improve the reaction activity of the electrocatalytic hydrogen production reaction. The technical problem to be solved by the present invention is: a Cdot@Ni2P composite electrocatalytic hydrogen production material, and a simple and efficient preparation method is provided. That is, a high-performance Cdot@Ni2P composite electrocatalytic hydrogen production material can be obtained by programmed temperature calcination. During the preparation of the Cdot@Ni2P composite electrocatalytic hydrogen production material, the raw materials used are convenient to obtain, inexpensive, no metal catalyst needs to be added, and the added carbon dots make the preparation process and conditions simple, with low cost and high yield.

[0004] The preparation method of the Cdot@Ni2P composite electrocatalytic hydrogen production material in the present invention includes the following steps: (1) Composite preparation: Dissolve 0.5 g of nickel chloride (analytical pure) in 20 mL of Cdot deionized aqueous solution and continuously stir for 20 min, and then dry it in a water bath at 95 °C for later use.

[0005] (2) Calcination reaction: The composite obtained in step (1) is mixed evenly with 0.67 g of sodium hypophosphite, placed in a tubular furnace, and heated to 350 °C at a heating rate of 1 °C / min in a H2 atmosphere and maintained for 2 h to obtain a calcined product.

[0006] (3) Washing and drying: The calcined product obtained in step (2) is taken out and ground after cooling, and centrifugally washed 3 times with water and ethanol. Finally, the washed composite is dried in an oven at 60 °C and stored for later use.

[0007] In a specific embodiment of the present invention, the specific types of the raw material nickel source added in step (1) are as follows: nickel chloride, nickel sulfate, nickel nitrate, etc. The concentration range of the Cdot deionized aqueous solution is: 10 mg / L to 30 mg / L.

[0008] In another specific embodiment of the present invention, the calcination reaction in step (2) can be prepared by a direct heating method or a programmed heating method; the protective gas uses a H2 atmosphere or a N2 atmosphere; the temperature is raised to 200 - 400 °C at a heating rate of 1 - 10 °C / min, and the heat treatment time is 0.5 - 3 h. Embodiment

[0009] The present invention will be further described below in conjunction with embodiments, but it is not a limitation of the present invention. Example

[0010] (1) Composite preparation: 0.5 g of nickel chloride (analytical pure) is added to 20 mL of 10 mg / L Cdot solution and stirred continuously for 20 min, and then evaporated to dryness in a 95 °C water bath.

[0011] (2) Calcination reaction: The composite obtained in step (1) is mixed evenly with 0.67 g of sodium hypophosphite, placed in a tubular furnace, and heated to 350 °C at a heating rate of 1 °C / min in a H2 atmosphere and maintained for 2 h to obtain a calcined product.

[0012] (3) Washing and drying: The calcined product obtained in step (2) is taken out and ground after cooling, and centrifugally washed 3 times with water and ethanol. Finally, the washed composite is dried in an oven at 60 °C and stored for later use. Example

[0013] (1) In Example 1, adjust "10 mg / L Cdot solution" in step (1) to "20 mg / L Cdot solution", and the remaining steps are the same as in Example 1. Example

[0014] (1) Modify the step in step (2) of Implementation Case 1, which is "heat to 350°C at a heating rate of 1°C / min in an H2 atmosphere and hold for 2 h", to "directly heat to 350°C in an N2 atmosphere and hold for 2 h", and the remaining steps are the same as those in Implementation Case 1.

Claims

1. A Cdot@Ni2P composite electrocatalytic hydrogen production material and its preparation method, characterized in that The method includes the following steps: During the synthesis of Cdot@Ni2P, 0.5 g of nickel chloride was dissolved in 20 mL of Cdot solution and continuously stirred for 20 min, and then evaporated to dryness in a water bath at 95 °C. Then the obtained complex was mixed evenly with 0.67 g of sodium hypophosphite, placed in a tube furnace, and heated to 350 °C at a heating rate of 1 °C / min in a H2 atmosphere and maintained for 2 h. After cooling, it was taken out and ground, and centrifugally washed 3 times with water and ethanol. Finally, the washed synthesis was dried in an oven at 60 °C and stored for standby.

2. The preparation method according to claim 1, characterized in that: The nickel source is one or more of nickel sulfate, nickel nitrate, and nickel chloride.

3. The preparation method according to claim 1, characterized in that: In the preparation of the complex solution, the concentration range of the Cdot deionized aqueous solution is: 10 mg / L to 30 mg / L.

4. The preparation method according to claim 1, characterized in that: The material forming method can be prepared by firing methods such as direct heating method and programmed heating method; the protective gas can use H2 atmosphere or N2 atmosphere protective gas; the temperature is raised to 200-400 °C at a heating rate of 1-10 °C / min, and the heat treatment time is 0.5-3 h.