CN116145184A - Preparation method and application of graphene-based composite binary metal sulfide electrocatalyst - Google Patents
Preparation method and application of graphene-based composite binary metal sulfide electrocatalyst Download PDFInfo
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Abstract
本发明涉及电催化技术领域,具体涉及一种石墨烯基复合二元金属硫化物电催化剂的制备方法和应用。以石墨烯作为制备反应的基体,通过水热一步法实现纳米片原位生长与金属硫化反应,制备出复合电催化剂。通过调控Fe元素的掺杂量,可有效改善复合催化剂的纳米结构,不仅可增加MoS2电催化剂的催化活性和反应位点,还能维持催化剂长时间催化析氢反应的稳定性。该方法可有效改善单组分催化剂在电解水反应过程中催化活性低和动力学速率差的问题;通过石墨烯复合,改善催化剂的导电性并增加催化过程的稳定性。这种方法简单易行,经济环保,可规模化生产并应用到其他金属硫化物电催化剂的制备中,实现电解水的应用。The invention relates to the technical field of electrocatalysis, in particular to a preparation method and application of a graphene-based composite binary metal sulfide electrocatalyst. Using graphene as the substrate for the preparation reaction, the composite electrocatalyst was prepared by realizing the in-situ growth of nanosheets and the metal sulfidation reaction by a hydrothermal one-step method. By adjusting the doping amount of Fe element, the nanostructure of the composite catalyst can be effectively improved, which can not only increase the catalytic activity and reaction sites of the MoS2 electrocatalyst, but also maintain the stability of the catalyst for hydrogen evolution reaction for a long time. The method can effectively improve the problems of low catalytic activity and poor kinetic rate of single-component catalysts in the process of electrolysis of water; through graphene compounding, the conductivity of the catalyst can be improved and the stability of the catalytic process can be increased. This method is simple, easy to operate, economical and environmentally friendly, and can be produced on a large scale and applied to the preparation of other metal sulfide electrocatalysts to realize the application of electrolyzed water.
Description
技术领域technical field
本发明属于电催化技术领域,具体涉及一种石墨烯基复合二元金属硫化物电催化剂的制备方法及应用,以石墨烯为反应基材,通过水热一步法实现纳米片原位生长及金属硫化反应,制备出复合电催化剂。The invention belongs to the technical field of electrocatalysis, and specifically relates to a preparation method and application of a graphene-based composite binary metal sulfide electrocatalyst. Using graphene as a reaction substrate, the in-situ growth of nanosheets and metal Sulfurization reaction to prepare a composite electrocatalyst.
背景技术Background technique
为应对能源与环境危机的冲击,减少化石能源的使用,近年我国对清洁能源的应用进行了大量的探索性工作。其中,氢能作为能量密度大于石油的能量载体,最具发展前景,它来源广泛成本低廉,消耗过程可能够实现零碳排放,是现阶段最理想的一次能源替代物。工业制氢的方法很多,其中电解水制氢以水为原料,过程清洁无污染物产生,产品具有较高的纯度,是最有效的制氢方式之一。在电解水过程中由于过电位的存在,使电解过程所需电压增大,极大的增加了能耗,因此探究能够降低过电势高效稳定的电催化剂变得十分必要。In order to cope with the impact of the energy and environmental crisis and reduce the use of fossil energy, my country has carried out a lot of exploratory work on the application of clean energy in recent years. Among them, hydrogen energy, as an energy carrier with an energy density greater than that of petroleum, has the most development prospects. It has a wide range of sources and low cost, and the consumption process can achieve zero carbon emissions. It is the most ideal primary energy substitute at this stage. There are many methods for industrial hydrogen production, among which water is used as raw material for hydrogen production by electrolysis, the process is clean and no pollutants are produced, and the product has high purity, which is one of the most effective methods of hydrogen production. Due to the existence of overpotential in the process of water electrolysis, the voltage required for the electrolysis process increases, which greatly increases energy consumption. Therefore, it is necessary to explore efficient and stable electrocatalysts that can reduce the overpotential.
相较于常规贵金属电催化剂,二维金属硫化物因其具有独特的电子结构,良好的多元掺杂共存性及优异的材料特性,被认为是一种极具前景的电催化剂。然而在电催化析氢反应中,金属硫化物虽然具有良好的反应活性,但由于其导电性较差且易团聚的缺点,导致其稳定性较差,限制了其进一步实际应用。通过增加金属硫化物的活性位点,增强材料导电性并进一步提升其稳定性,是改善金属硫化物催化特性的有效手段。Compared with conventional noble metal electrocatalysts, two-dimensional metal sulfides are considered to be a promising electrocatalyst due to their unique electronic structure, good multi-doping coexistence and excellent material properties. However, in the electrocatalytic hydrogen evolution reaction, although metal sulfides have good reactivity, their poor conductivity and easy agglomeration lead to poor stability, which limits their further practical applications. It is an effective means to improve the catalytic properties of metal sulfides by increasing the active sites of metal sulfides, enhancing the conductivity of materials and further improving their stability.
发明内容Contents of the invention
本发明涉及一种石墨烯基复合二元金属硫化物电催化剂的制备方法和应用。该方法以薄层石墨烯作为反应的基体,通过水热一步法实现纳米片原位生长与金属硫化反应,制备出石墨烯基复合二元金属硫化物电催化剂,命名为rGO@FeS2MoS2。该催化剂具有活性高,稳定性好及成本低等优点,具有良好的应用前景。The invention relates to a preparation method and application of a graphene-based composite binary metal sulfide electrocatalyst. This method uses thin-layer graphene as the substrate for the reaction, and realizes the in-situ growth of nanosheets and metal sulfidation reaction through a hydrothermal one-step method, and prepares a graphene-based composite binary metal sulfide electrocatalyst, named rGO@FeS 2 MoS 2 . The catalyst has the advantages of high activity, good stability, low cost and the like, and has good application prospects.
本发明为了实现上述目的,所采取的技术方案为:In order to achieve the above object, the present invention adopts the following technical solutions:
一种石墨烯基复合二元金属硫化物电催化剂的制备方法,包括以下步骤:A preparation method of a graphene-based composite binary metal sulfide electrocatalyst, comprising the following steps:
将氯化亚铁、七钼酸铵、薄层石墨烯片加入去离子水中,超声分散均匀(优选超声3小时)得到溶液A;将硫脲搅拌溶解于甘油中得到溶液B;然后将溶液A放置至分层后取上层附着的石墨烯(优选放置3小时),然后将上层附着的石墨烯和溶液B混合均匀后置于高压反应釜中,密封后于180-260℃下进行水热反应10-30h(优选为在220℃下水热反应18h),反应完全后,自然冷却至室温后,离心所得固体洗涤(优选为依次用无水乙醇和水洗涤),过滤后真空干燥,得到石墨烯基复合二元金属硫化物电催化剂。Add ferrous chloride, ammonium heptamolybdate, and thin-layer graphene sheets into deionized water, and disperse uniformly (preferably ultrasonically for 3 hours) to obtain solution A; stir and dissolve thiourea in glycerin to obtain solution B; then dissolve solution A Put the graphene attached to the upper layer after layering (preferably place it for 3 hours), then mix the graphene attached to the upper layer and solution B evenly and place it in a high-pressure reactor, seal it and carry out hydrothermal reaction at 180-260°C 10-30h (preferably hydrothermal reaction at 220°C for 18h), after the reaction is complete, cool naturally to room temperature, centrifuge the obtained solid to wash (preferably wash with absolute ethanol and water in sequence), filter and vacuum dry to obtain graphene based composite binary metal sulfide electrocatalysts.
本发明将金属盐与石墨烯超声分散到去离子中形成溶液A,该步骤使金属离子首先能够均匀吸附在石墨烯表面,可有效避免后续反应纳米片层团聚,实现石墨烯两侧纳米片均匀原位生长及形貌均匀控制。In the present invention, metal salt and graphene are ultrasonically dispersed into deionized solution A to form solution A. This step enables metal ions to be evenly adsorbed on the surface of graphene, which can effectively avoid the subsequent reaction of nanosheet agglomeration, and realize the uniformity of nanosheets on both sides of graphene. In situ growth and uniform control of morphology.
通过在溶液B中将硫脲溶于甘油中,甘油可有效增加纳米片层的缺陷,增加催化反应活性点位。By dissolving thiourea in glycerol in solution B, glycerin can effectively increase the defects of nanosheets and increase the active sites of catalytic reactions.
优选的,所述真空干燥的条件为在60℃下真空干燥12小时。Preferably, the vacuum drying condition is vacuum drying at 60° C. for 12 hours.
优选的,所述薄层石墨烯片为:采用传统hummers法制备的氧化石墨烯粉末经过超声与陈化处理后得到的具有薄层结构的石墨烯片;Preferably, the thin-layer graphene sheet is: a graphene sheet with a thin-layer structure obtained after the graphene oxide powder prepared by the traditional hummers method is subjected to ultrasonic and aging treatments;
所述传统hummers法参照以下文献进行:Hummers,W.S.;Offeman,R.E.Preparation of Graphitic Oxide.J.Am.Chem.Soc.1958,80,1339-1339.The traditional hummers method is carried out with reference to the following documents: Hummers, W.S.; Offeman, R.E.Preparation of Graphitic Oxide.J.Am.Chem.Soc.1958,80,1339-1339.
更优选的,所述超声与陈化处理的步骤为:将氧化石墨烯粉末超声分散均匀后,放置过夜陈化,取上层液离心后的固体在40℃下干燥。More preferably, the steps of ultrasonication and aging treatment are as follows: uniformly disperse the graphene oxide powder by ultrasonication, leave it to age overnight, take the supernatant liquid and centrifuge the solid and dry it at 40°C.
优选的,所述氯化亚铁、七钼酸铵的摩尔比为(1~4):1。Preferably, the molar ratio of ferrous chloride to ammonium heptamolybdate is (1-4):1.
优选的,所述氯化亚铁、薄层氧化石墨烯片与硫脲的用量比为(0.25~1)mmol:0.1g:(0.1~1.0)g。Preferably, the ratio of ferrous chloride, thin-layer graphene oxide sheets and thiourea is (0.25-1) mmol: 0.1 g: (0.1-1.0) g.
本发明还提供了上述制备方法得到的催化剂在电解水析氢中的应用。The present invention also provides the application of the catalyst obtained by the above preparation method in electrolyzing water for hydrogen evolution.
本发明利用二元金属共掺杂及石墨烯碳材料复合的手段,实现高效稳定石墨烯基复合二元金属硫化物电催化剂的制备,避免高温烧结造成颗粒团聚,有效改善二维金属硫化物的电子转移能力,并进一步增强了其催化反应活性与稳定性,具有良好的应用前景。The present invention utilizes the means of binary metal co-doping and graphene carbon material compounding to realize the preparation of high-efficiency and stable graphene-based composite binary metal sulfide electrocatalysts, avoid particle agglomeration caused by high-temperature sintering, and effectively improve the performance of two-dimensional metal sulfides. Electron transfer ability, and further enhance its catalytic activity and stability, has a good application prospect.
与现有技术相比,本发明的优势和有益效果如下:Compared with prior art, advantage and beneficial effect of the present invention are as follows:
(1)通过调控Fe元素的掺杂量,可有效改善复合催化剂的纳米结构,不仅可增加MoS2电催化剂的催化活性和反应位点,还能维持催化剂长时间催化析氢反应的稳定性。(1) By adjusting the doping amount of Fe element, the nanostructure of the composite catalyst can be effectively improved, which can not only increase the catalytic activity and reaction sites of the MoS2 electrocatalyst, but also maintain the stability of the catalyst for the long-term hydrogen evolution reaction.
(2)石墨烯具有可调控的二维结构及良好的导电性,不仅能够提供金属配位点,实现二维金属硫化物的均匀原位生成,有效避免活性催化剂的团聚;而且石墨烯作为夹层材料能够为催化剂提供了较低的电荷转移电阻,并进一步增加催化剂的HER活性。(2) Graphene has an adjustable two-dimensional structure and good electrical conductivity. It can not only provide metal coordination points, realize the uniform in-situ generation of two-dimensional metal sulfides, and effectively avoid the agglomeration of active catalysts; and graphene as an interlayer The material can provide the catalyst with lower charge transfer resistance and further increase the HER activity of the catalyst.
(3)该种方法简单易行,经济环保,可规模化生产并应用到其他如Ni、Co等金属硫化物电催化剂的制备中,实现在电解水中的应用。(3) This method is simple and easy, economical and environmentally friendly, and can be produced on a large scale and applied to the preparation of other metal sulfide electrocatalysts such as Ni and Co to realize the application in electrolysis of water.
附图说明Description of drawings
图1为实施例1所得催化剂的X射线衍射图谱(XRD);Fig. 1 is the X-ray diffraction spectrum (XRD) of
图2为实施例1所得催化剂的扫描电镜图(SEM);Fig. 2 is the scanning electron micrograph (SEM) of
图3为实施例1-3与对比例所得催化剂在电解液中的电极极化曲线;Fig. 3 is the electrode polarization curve of embodiment 1-3 and comparative example gained catalyst in electrolyte;
图4为实施例1-3与对比例所得催化剂的电极极化曲线对应的Tafel斜率;Fig. 4 is the Tafel slope corresponding to the electrode polarization curve of the catalyst obtained in Examples 1-3 and Comparative Examples;
图5为实施例1所得具有薄层结构的氧化石墨烯片的TEM图。Figure 5 is a TEM image of the graphene oxide sheet with a thin layer structure obtained in Example 1.
具体实施方式Detailed ways
下面结合具体实施例对本发明的技术方案进行进一步详细说明。The technical solution of the present invention will be further described in detail below in conjunction with specific embodiments.
以下实施例中采用传统hummers法制备氧化石墨烯参照以下文献进行:Hummers,W.S.;Offeman,R.E.Preparation of Graphitic Oxide.J.Am.Chem.Soc.1958,80,1339-1339.In the following examples, the traditional hummers method is used to prepare graphene oxide with reference to the following documents: Hummers, W.S.;
以下诸实施例中所用甘油即无水丙三醇;Glycerol used in the following examples is anhydrous glycerol;
所用浓硫酸和盐酸的浓度均是质量百分比浓度。The concentrations of the used concentrated sulfuric acid and hydrochloric acid are mass percent concentrations.
实施例1:一种石墨烯基复合二元金属硫化物电催化剂的制备方法,包括如下步骤:Embodiment 1: a kind of preparation method of graphene-based composite binary metal sulfide electrocatalyst comprises the steps:
(1)采用传统hummers法制备氧化石墨烯并进行初次离心干燥:在冰水浴条件下,装配好250mL的反应瓶,向其中加入10mL浓度95%的浓硫酸,搅拌下加入2g石墨粉和1g硝酸钠的固体混合物,再分3次加入6g高锰酸钾,控制反应温度不超过20℃,搅拌反应30min,然后升温到35℃左右,继续搅拌30min,再缓慢加入100mL去离子水,继续搅拌20min后,加入2mL双氧水还原残留的氧化剂,使溶液变为亮黄色。趁热过滤,并用5%HC1溶液和去离子水洗涤直到滤液中无硫酸根被检测到为止。最后将滤饼置于60℃的真空干燥箱中充分干燥得氧化石墨粉末,保存备用。(1) Prepare graphene oxide by the traditional hummers method and carry out initial centrifugal drying: under the condition of ice-water bath, assemble a 250mL reaction bottle, add 10mL concentrated sulfuric acid with a concentration of 95% to it, add 2g graphite powder and 1g nitric acid under stirring Sodium solid mixture, then add 6g potassium permanganate in 3 times, control the reaction temperature not to exceed 20°C, stir for 30min, then raise the temperature to about 35°C, continue stirring for 30min, then slowly add 100mL deionized water, continue stirring for 20min Afterwards, 2 mL of hydrogen peroxide was added to reduce the residual oxidant, making the solution turn bright yellow. Filtrate while hot and wash with 5% HCl solution and deionized water until no sulfate is detected in the filtrate. Finally, the filter cake was fully dried in a vacuum oven at 60°C to obtain graphite oxide powder, which was stored for future use.
将获得的氧化石墨粉末分散到去离子水中,以60W功率超声3h,沉淀过夜,取上层液离心后的固体放入烘箱内,在40℃下干燥3h,即得到具有薄层结构的氧化石墨烯片待用,其TEM图见图5;Disperse the obtained graphite oxide powder into deionized water, sonicate with 60W power for 3 hours, settle overnight, take the supernatant and centrifuge the solid into an oven, and dry at 40°C for 3 hours to obtain graphene oxide with a thin layer structure The sheet is ready for use, and its TEM image is shown in Figure 5;
(2)将0.25mmol氯化亚铁、0.25mmol七钼酸铵、0.1g步骤(1)制备得薄层氧化石墨烯片加入到30mL去离子水中,60W下超声分散3小时,得到溶液A(该步骤使金属离子首先能够均匀吸附在石墨烯表面,可有效避免后续反应纳米片层团聚,实现石墨烯两侧纳米片均匀原位生长及形貌均匀控制),将0.571g硫脲搅拌溶解于5mL甘油中得到溶液B(将硫脲溶于甘油中,甘油可有效增加纳米片层的缺陷,增加催化反应活性点位)。将溶液A放置3小时后取上层附着的石墨烯,然后将其与溶液B混合在超声下搅拌30min以保证原料分散均匀,将混合均匀得到的溶液转移至50mL的高压反应釜中,密封后于220℃下水热反应18h(水热反应能够实现金属硫化与石墨烯还原),接着自然冷却至室温后离心,所得固体依次用无水乙醇和水洗涤各4次,洗涤后的固体在60℃真空干燥12小时,得到产物-高效稳定石墨烯基复合二元金属硫化物电催化剂。(2) 0.25mmol ferrous chloride, 0.25mmol ammonium heptamolybdate, 0.1g step (1) prepared thin-layer graphene oxide sheets were added to 30mL deionized water, and ultrasonically dispersed for 3 hours under 60W to obtain solution A ( This step enables metal ions to be evenly adsorbed on the graphene surface at first, which can effectively avoid the subsequent reaction of nanosheets from agglomeration, and realize the uniform in-situ growth of nanosheets on both sides of the graphene and the uniform control of the shape), stirring and dissolving 0.571g of thiourea in Solution B was obtained in 5 mL glycerol (dissolving thiourea in glycerin, glycerin can effectively increase the defects of nanosheets and increase the catalytic reaction active sites). Place solution A for 3 hours and take the graphene attached to the upper layer, then mix it with solution B and stir under ultrasound for 30 minutes to ensure that the raw materials are evenly dispersed, and transfer the uniformly mixed solution to a 50mL autoclave. Hydrothermal reaction at 220°C for 18 hours (hydrothermal reaction can realize metal vulcanization and graphene reduction), then naturally cool to room temperature and centrifuge, the obtained solid is washed with absolute ethanol and water for 4 times each, and the washed solid is placed in a vacuum at 60°C After drying for 12 hours, the product-highly efficient and stable graphene-based composite binary metal sulfide electrocatalyst was obtained.
实施例2:按照实施例1的方法制备高效稳定石墨烯基复合二元金属硫化物电催化剂,不同的是:将氯化亚铁的用量更改为0.5mmol,其他原料种类和用量,反应条件和参数均不变。Embodiment 2: Prepare efficient and stable graphene-based composite binary metal sulfide electrocatalyst according to the method of
实施例3:按照实施例1的方法制备高效稳定石墨烯基复合二元金属硫化物电催化剂,不同的是:将氯化亚铁的用量更改为1mmol,其他原料种类和用量,反应条件和参数均不变。Example 3: Prepare efficient and stable graphene-based composite binary metal sulfide electrocatalyst according to the method of Example 1, the difference is: the amount of ferrous chloride is changed to 1 mmol, other raw material types and amounts, reaction conditions and parameters are unchanged.
对比例:将0.5mmol氯化亚铁、0.25mmol七钼酸铵加入到30mL去离子水中,超声分散3小时,记为溶液A,同时将0.571g硫脲搅拌溶解于5mL甘油记为溶液B。溶液A放置3小时后,与溶液B混合,在超声下搅拌30min以保证原料分散均匀,将混合后的溶液转移至50mL的高压反应釜中,密封后于220℃下水热处理18h。结束后自然冷却至室温后离心,所得固体,接着依次用乙醇和水洗涤4次,离心后的固体在60℃真空干燥12小时,得到产物复合二元金属硫化物电催化剂。Comparative example: Add 0.5mmol ferrous chloride and 0.25mmol ammonium heptamolybdate into 30mL deionized water, ultrasonically disperse for 3 hours, and record it as solution A, while stirring and dissolving 0.571g thiourea in 5mL glycerin, record it as solution B. After solution A was left for 3 hours, it was mixed with solution B, stirred under ultrasonic for 30 minutes to ensure that the raw materials were uniformly dispersed, and the mixed solution was transferred to a 50mL autoclave, sealed and hydrothermally treated at 220°C for 18 hours. After the end, it was naturally cooled to room temperature and then centrifuged, and the obtained solid was washed with ethanol and water four times in sequence, and the centrifuged solid was vacuum-dried at 60°C for 12 hours to obtain the product composite binary metal sulfide electrocatalyst.
图1为实施例1所得催化剂的XRD谱图,可知:所得催化剂是由FeS2(PDF74-1051)和MoS2(PDF 86-2308)组成,同时证明了FeS2的引入没有改变MoS2的结构特性。Fig. 1 is the XRD spectrogram of the catalyst obtained in Example 1, as can be seen: the obtained catalyst is composed of FeS2 (PDF74-1051) and MoS2 (PDF 86-2308), and it is proved that the introduction of FeS2 does not change the structure of MoS2 characteristic.
图2为实施例1所得催化剂的扫描电镜图,由图可看出:所得电催化剂中均一结构的金属硫化物纳米片以薄层石墨烯为模板均匀生长在其两侧,展现出夹层三明治结构。这种结构能够提供大量的活性位点,能够极大促进催化活性与效率。同时,金属硫化物纳米片与石墨烯的表面化学键发生相互交联作用,有效减少催化过程电子传递阻力,增强过程稳定性。Figure 2 is a scanning electron microscope image of the catalyst obtained in Example 1. It can be seen from the figure that the metal sulfide nanosheets with a uniform structure in the obtained electrocatalyst grow uniformly on both sides of the catalyst with a thin layer of graphene as a template, showing a sandwich sandwich structure . This structure can provide a large number of active sites, which can greatly promote the catalytic activity and efficiency. At the same time, the surface chemical bonds between metal sulfide nanosheets and graphene are cross-linked, which effectively reduces the resistance of electron transfer in the catalytic process and enhances the stability of the process.
电解析氢活性和稳定性测试:Electrolytic hydrogen activity and stability test:
对实施例1中制备的催化剂进行电解析氢测试:在电化学工作站上采用三电极测试体系,工作电极为催化剂电极(4mg实施例1所得催化剂分散于1mL体积比95:5的无水乙醇与nafion溶液混合液中得分散液,取14μL所得分散液均匀滴在玻碳电极上制得催化剂电极),对电极为石墨电极,参比电极为Ag/AgCl(3.5M KCl)电极。测试电解液为25℃、1mmol/L的氢氧化钾水溶液,测试中通高纯氮气进行饱和处理,测试温度为室温。线性扫描伏安曲线测试时,扫描速率为5mV/s。The catalyst prepared in Example 1 was tested for electrolysis of hydrogen: on the electrochemical workstation, a three-electrode test system was adopted, and the working electrode was a catalyst electrode (4 mg of the catalyst obtained in Example 1 was dispersed in 1 mL of dehydrated alcohol with a volume ratio of 95:5 and Nafion solution mixed solution to obtain a dispersion, get 14 μ L of the resulting dispersion and evenly drop it on a glassy carbon electrode to make a catalyst electrode), the counter electrode is a graphite electrode, and the reference electrode is an Ag/AgCl (3.5M KCl) electrode. The test electrolyte is 25°C, 1mmol/L potassium hydroxide aqueous solution. During the test, high-purity nitrogen gas is passed through for saturation treatment, and the test temperature is room temperature. When testing the linear sweep voltammetry curve, the sweep rate is 5mV/s.
按照上述方式进行其他催化剂以及对比例的测试。Tests of other catalysts and comparative examples were carried out in the manner described above.
图3为实施例1-3所得产物在电解液中的电极极化曲线,由曲线可知,实施例1-3所得催化剂在10mA﹒cm-2的电流密度下,过电位分别为163mV、93mV、166mV,展现出良好的HER活性,而对比例由于未复合石墨烯,其在同等电流密度下,过电位为300mV,表明石墨烯对催化剂活性提高起到重要作用。Fig. 3 is the electrode polarization curve of embodiment 1-3 gained product in electrolytic solution, as can be seen from curve, embodiment 1-3 gained catalyst is in 10mA. At the current density of cm -2 , the overpotentials were 163mV, 93mV, and 166mV, respectively, showing good HER activity, while the comparative example had an overpotential of 300mV at the same current density due to the fact that graphene was not compounded, indicating that graphene has a good HER activity. The increase in catalyst activity plays an important role.
图4为实施例所得产物的电极极化曲线对应的Tafel斜率,由曲线可知,实施例1-3所得催化剂的Tafel斜率为70.250mV﹒dec-1、50mV﹒dec-1、79.150mV﹒dec-1,可看出通过掺杂配比调控,能够有效增强电催化剂的HER动力学性能。对比例的Tafel斜率为71.30mV﹒dec-1,表明石墨烯能够有效增强金属硫化物的动力学性能。Fig. 4 is the Tafel slope corresponding to the electrode polarization curve of the product obtained in the embodiment, as can be seen from the curve, the Tafel slope of the catalyst obtained in Examples 1-3 is 70.250mV. dec -1 、50mV. dec -1 、79.150mV. dec -1 , it can be seen that the HER kinetic performance of the electrocatalyst can be effectively enhanced by adjusting the doping ratio. The Tafel slope of the comparative example is 71.30mV. dec -1 , indicating that graphene can effectively enhance the kinetic properties of metal sulfides.
本发明利用二元金属共掺杂及石墨烯碳材料复合的手段,实现高效稳定石墨烯基复合二元金属硫化物电催化剂的制备,避免高温烧结造成颗粒团聚,有效改善二维金属硫化物的电子转移能力,并进一步增强了其催化反应活性与稳定性,具有良好的应用前景。The present invention utilizes the means of binary metal co-doping and graphene carbon material compounding to realize the preparation of high-efficiency and stable graphene-based composite binary metal sulfide electrocatalysts, avoid particle agglomeration caused by high-temperature sintering, and effectively improve the performance of two-dimensional metal sulfides. Electron transfer ability, and further enhance its catalytic activity and stability, has a good application prospect.
应当说明的是,对于本领域普通技术人员而言,可以根据上述说明加以改进或变换,而这些改进或变换都应属于本发明所附权利要求书的保护范围。It should be noted that those skilled in the art can make improvements or transformations based on the above description, and these improvements or transformations should fall within the protection scope of the appended claims of the present invention.
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