Disclosure of Invention
The invention aims to provide a tungsten nitride nano porous film integrated electrode with ruthenium nanoclusters loaded in a limited domain, and a preparation method and application thereof.
According to the invention, a metal tungsten foil is used as a template and a tungsten source, tungsten nitride is directly grown on the tungsten foil by adopting a three-step method (anodic oxidation, hydrothermal limited-area loading and chemical vapor phase nitridation) for the first time under the condition of not additionally adding tungsten salt, so that the tungsten nitride nano porous film integrated electrode with the ruthenium nanocluster loaded in the limited area is prepared, and the obtained tungsten nitride nano porous film electrode can be used as a hydrogen evolution catalyst electrode under acidic and alkaline conditions. The anodized tungsten foil can not only provide a tungsten source for tungsten nitride, but also serve as a conductive substrate to stabilize the material, thereby improving its capacity, catalytic activity and cycling stability.
The technical scheme adopted by the invention is as follows:
a preparation method of a tungsten nitride nano porous film integrated electrode with ruthenium nanoclusters loaded in a limited domain comprises the steps of firstly synthesizing a tungsten oxide nano porous film, then taking the tungsten oxide nano porous film as a carrier, loading the ruthenium nanoclusters in the tungsten oxide nano porous pore channels and the hollow pore walls in a limited domain mode through a hydrothermal method, and then synthesizing the tungsten nitride nano porous film integrated electrode with ruthenium nanoclusters loaded in a limited domain mode in one step through a chemical vapor deposition method, wherein the tungsten nitride nano porous film integrated electrode has a stable structural morphology.
Further, the preparation method of the tungsten nitride nano-porous film integrated electrode with the ruthenium nanocluster loaded in a limited domain specifically comprises the following steps:
(1) and (3) anode treatment: ultrasonically cleaning 20-320 square mm tungsten foil with acetone, anhydrous ethanol and deionized water respectively to remove organic matters on the surface, and drying with nitrogen; the cleaned tungsten foil is used as an anode, a platinum sheet is used as a cathode, the surface area ratio of the cathode to the anode is controlled to be 1:1-6:1, and a 10-70V direct current constant voltage power supply is adopted to dissolve 0.15-0.3mol/L oxalic acid and 0.1-0.3mol/L Na2SO4Anodizing in 0.01-0.03mol/L NaF electrolyte for 10-100 minutes, cleaning with flowing deionized water, and blow-drying with nitrogen to obtain anode nano porous tungsten oxide;
(2) carrying out limited loading of ruthenium nanoclusters in tungsten oxide nanopores: 0.4-2mg of RuCl3·3H2Dissolving O in a deionized water solvent, settling a magnetic stirrer at the bottom of the solvent, placing the nano porous tungsten oxide obtained in the step (1) in a cubic copper cage and suspending on the middle upper part of the solvent, stirring for 1-6h and uniformly mixing on the magnetic stirrer at the air atmosphere and room temperature, transferring the solution and the nano porous tungsten oxide into a reaction kettle, packaging, heating in an oven at 100-200 ℃ for 5-20h, and then cooling to room temperature in the oven; taking out the nano porous tungsten oxide, washing with absolute ethyl alcohol and deionized water, and drying;
(3) CVD nitridation reaction: and (3) placing the nano porous tungsten oxide obtained in the step (2) in the center of a quartz tube of a CVD tube furnace, setting the furnace temperature at 500-900 ℃, introducing argon and ammonia gas, keeping the total pressure at 0.25-0.4KPa, carrying out nitridation reaction for 0.5-3h, and then naturally cooling to room temperature under the argon atmosphere to obtain the tungsten nitride nano porous film integrated electrode loaded with ruthenium nanoclusters in a limited area.
Further, the reaction kettle is a reaction kettle with a polytetrafluoroethylene substrate.
Further, in the CVD nitridation reaction process, ammonia is used as a reaction gas, and the furnace temperature is increased to 500-900 ℃ at a constant speed in the presence of argon and ammonia.
Furthermore, in the CVD nitridation reaction process, the flow rate of the argon gas is 50-200sccm, and the flow rate of the ammonia gas is 10-100 sccm.
Further, during the CVD nitridation reaction, the reaction time was 3 h.
Further, RuCl in the step (2)3·3H2The mass volume ratio of the O to the deionized water is 1:6-30 mg/ml.
The invention also provides a tungsten nitride nano porous film integrated electrode of the limited-domain loaded ruthenium nanocluster prepared by the preparation method.
The invention also provides application of the tungsten nitride nano porous film integrated electrode with the limited-domain loaded ruthenium nanocluster in catalytic hydrogen evolution in acidic electrolyzed water and catalytic hydrogen evolution in alkaline electrolyzed water.
Further, the application process comprises the following steps: performing electrochemical measurement on an electrochemical workstation by using a three-electrode system; the integrated electrode is encapsulated by using a sealing film and a lead and directly used as a working electrode.
Compared with the prior art, the invention has the following advantages:
(1) in the composite electrode prepared by the invention, the tungsten foil is used as a conductive substrate, and meanwhile, a tungsten source is provided, so that the cost is low, the used elements are rich in reserves, the preparation process is simple, tungsten nitride directly and uniformly grows on the tungsten foil, and the mechanical stability of the electrode structure is effectively improved;
(2) compared with the traditional process, the integrated electrode prepared by the invention does not need to add auxiliary materials such as conductive agents, binders and the like in the electrode preparation process. The process is simple and easy, the cost is low, and the period is short. The obtained electrode material can be directly applied to electrolytic water catalysis, when the electrode material is used as an electrolytic water catalysis electrode, the operation processes of grinding, slurry preparation, drying and the like are not needed, an additional conductive substrate is not needed, and the electrode material has the advantages of high catalysis performance, long cycle life, high capacity and high cycle stability;
(3) the carrier of the tungsten nitride nano porous film with the ruthenium nanoclusters loaded in the limited domain prepared by the process is a hollow porous tungsten nitride nano porous film different from the traditional pore channel, is favorable for high dispersion of the ruthenium nanoclusters, improves the exposure of active sites, increases the active specific surface area of tungsten nitride, is easy for permeation of electrolyte, and is favorable for conduction of electrons;
(4) the tungsten nitride nano porous film material with the limited-area supported ruthenium nanoclusters prepared by the process has electro-catalytic hydrogen evolution performance in acidic and alkaline electrolytes, namely high activity, low initial potential, high current density, small Tafel slope, stable performance and the like.
Detailed Description
The invention is further illustrated with reference to the following figures and examples.
Example 1:
(1) and (3) anode treatment: ultrasonically cleaning a 1 square centimeter tungsten foil by using acetone, absolute ethyl alcohol and deionized water respectively, removing organic matters on the surface, and drying by using nitrogen; using a circular tungsten foil with an exposed surface diameter of 0.5 square centimeter and an area of 0.19625 square centimeters as an anode, 0.15mol/L oxalic acid and 0.1mol/L Na2SO4And 0.01mol/L NaF electrolyte, a platinum sheet as a cathode, and anodizing at 60V for 60 minutes. After the reaction is finished, washing a sample by using flowing deionized water, and drying by using nitrogen to obtain the anode nano-porous tungsten oxide;
(2) carrying out limited loading of ruthenium nanoclusters in tungsten oxide nanopores: 1mg of RuCl3·3H2Dissolving O in 6ml of deionized water solvent, putting in a magneton, precipitating at the bottom of the solvent, putting the nano-porous tungsten oxide obtained in the step (1) in a cubic copper cage and suspending on the middle-upper part of the solvent, stirring for 3 hours at room temperature in an air atmosphere on a magnetic stirrer, transferring the solution and the nano-porous tungsten oxide to a reaction kettle with a polytetrafluoroethylene substrate, packaging, putting in a 100 ℃ drying oven, heating for 10 hours, and then cooling to room temperature in the drying oven; then taking out the nano-porous tungsten oxide, washing with absolute ethyl alcohol and deionized water, and drying.
(3) CVD nitridation reaction: and (3) placing the nano porous tungsten oxide obtained in the step (2) in the center of a quartz tube of a CVD tube furnace, setting the furnace temperature to be 800 ℃, the argon gas flow to be 100sccm, the ammonia gas flow to be 50sccm and the total gas pressure to be 0.3KPa, carrying out nitridation reaction for 1h, and then naturally cooling to room temperature under the argon atmosphere to obtain the tungsten nitride nano porous film integrated electrode with the ruthenium nanoclusters loaded in a limited area.
As shown in fig. 1, which is an XRD pattern of the product obtained in this example 1, the XRD pattern of the material corresponds to the (111), (200), (220) and (311) crystal planes of tungsten nitride (JCPDS No.75-1012) and the (110), (200) and (211) crystal planes of simple substance tungsten (JCPDS No.04-0806) in the standard card library, which illustrates the successful synthesis of the prepared tungsten nitride nano-porous film material with domain-limited supported ruthenium nanoclusters integrated electrode, and the metal is amorphous and does not contain any crystalline metal phase.
Example 2
(1) And (3) anode treatment: ultrasonically cleaning a 1 square centimeter tungsten foil by using acetone, absolute ethyl alcohol and deionized water respectively, removing organic matters on the surface, and drying by using nitrogen; 0.15mo of a circular tungsten foil having an exposed surface diameter of 0.5 cm square and an area of 0.19625 cm square as an anodeL/L oxalic acid, 0.1mol/L Na2SO4And 0.01mol/L NaF electrolyte, a platinum sheet as a cathode, and anodizing at 60V for 60 minutes. After the reaction is finished, washing a sample by using flowing deionized water, and drying by using nitrogen to obtain the anode nano-porous tungsten oxide;
(2) carrying out limited loading of ruthenium nanoclusters in tungsten oxide nanopores: 1mg of RuCl3·3H2Dissolving O in 30ml of deionized water solvent, putting in a magneton, precipitating at the bottom of the solvent, putting the nano-porous tungsten oxide obtained in the step (1) in a cubic copper cage and suspending on the middle-upper part of the solvent, stirring for 3 hours at room temperature in an air atmosphere on a magnetic stirrer, transferring the solution and the nano-porous tungsten oxide to a reaction kettle with a polytetrafluoroethylene substrate, packaging, putting in a 100 ℃ drying oven, heating for 12 hours, and then cooling to room temperature in the drying oven; then taking out the nano-porous tungsten oxide, washing with absolute ethyl alcohol and deionized water, and drying.
(3) CVD nitridation reaction: and (3) placing the nano porous tungsten oxide obtained in the step (2) in the center of a quartz tube of a CVD tube furnace, setting the furnace temperature to be 800 ℃, the argon gas flow to be 100sccm, the ammonia gas flow to be 50sccm and the total gas pressure to be 0.3KPa, carrying out nitridation reaction for 1h, and then naturally cooling to room temperature under the argon atmosphere to obtain the tungsten nitride nano porous film integrated electrode with the ruthenium nanoclusters loaded in a limited area.
As shown in fig. 2, which is an SEM image of the product obtained in this example, it can be seen that the morphology of the product is Ru nanocluster confinement loading and is uniformly dispersed in the porous tungsten nitride nanopores and hollow hole walls.
Example 3
(1) And (3) anode treatment: ultrasonically cleaning a 1 square centimeter tungsten foil by using acetone, absolute ethyl alcohol and deionized water respectively, removing organic matters on the surface, and drying by using nitrogen; using a circular tungsten foil with an exposed surface diameter of 0.5 square centimeter and an area of 0.19625 square centimeters as an anode, 0.15mol/L oxalic acid and 0.1mol/L Na2SO4And 0.01mol/L NaF electrolyte, a platinum sheet as a cathode, and anodizing at 60V for 60 minutes. After the reaction is finished, the sample is washed clean by flowing deionized water and is usedDrying the anode nano porous tungsten oxide by nitrogen to obtain anode nano porous tungsten oxide;
(2) carrying out limited loading of ruthenium nanoclusters in tungsten oxide nanopores: 1mg of RuCl3·3H2Dissolving O in 12ml of deionized water solvent, putting in a magneton, precipitating at the bottom of the solvent, putting the nano-porous tungsten oxide obtained in the step (1) in a cubic copper cage and suspending on the middle-upper part of the solvent, stirring for 3 hours at room temperature in an air atmosphere on a magnetic stirrer, transferring the solution and the nano-porous tungsten oxide to a reaction kettle with a polytetrafluoroethylene substrate, packaging, putting in a 100 ℃ drying oven, heating for 10 hours, and then cooling to room temperature in the drying oven; then taking out the nano-porous tungsten oxide, washing with absolute ethyl alcohol and deionized water, and drying.
(3) CVD nitridation reaction: and (3) placing the nano porous tungsten oxide obtained in the step (2) in the center of a quartz tube of a CVD tube furnace, setting the furnace temperature at 700 ℃, the argon gas flow at 100sccm, the ammonia gas flow at 50sccm and the total gas pressure at 0.3KPa to perform nitridation reaction for 1h, and then naturally cooling to room temperature under the argon atmosphere to obtain the tungsten nitride nano porous film integrated electrode with the ruthenium nanoclusters loaded in a limited area.
As shown in fig. 3, which is a TEM topography of the tungsten nitride nanoporous thin film integrated electrode with ruthenium nanoclusters loaded in a limited domain prepared in this example, a graph shows a nanoporous structure of tungsten nitride in a sample, and a pore size is about 100nm, and a graph b shows the uniform dispersion and hollow holes of ruthenium nanoclusters.
Example 4
(1) And (3) anode treatment: ultrasonically cleaning a 1 square centimeter tungsten foil by using acetone, absolute ethyl alcohol and deionized water respectively, removing organic matters on the surface, and drying by using nitrogen; using a circular tungsten foil with an exposed surface diameter of 0.5 square centimeter and an area of 0.19625 square centimeters as an anode, 0.15mol/L oxalic acid, 0.01mol/L NaF and 0.1mol/L Na2SO4The electrolyte solution (2) was anodized at a voltage of 60V for 60 minutes with a platinum sheet as a cathode. After the reaction is finished, washing a sample by using flowing deionized water, and drying by using nitrogen to obtain the anode nano-porous tungsten oxide;
(2) carrying out limited loading of ruthenium nanoclusters in tungsten oxide nanopores: 1mg of RuCl3·3H2Dissolving O in 12ml of deionized water solvent, putting in a magneton, precipitating at the bottom of the solvent, putting the nano-porous tungsten oxide obtained in the step (1) in a cubic copper cage and suspending on the middle-upper part of the solvent, stirring for 3 hours at room temperature in an air atmosphere on a magnetic stirrer, transferring the solution and the nano-porous tungsten oxide to a reaction kettle with a polytetrafluoroethylene substrate, packaging, putting in a 100 ℃ drying oven, heating for 15 hours, and then cooling to room temperature in the drying oven; then taking out the nano-porous tungsten oxide, washing with absolute ethyl alcohol and deionized water, and drying.
(3) CVD nitridation reaction: and (3) placing the nano porous tungsten oxide obtained in the step (2) in the center of a quartz tube of a CVD tube furnace, setting the furnace temperature to be 800 ℃, the argon gas flow to be 100sccm, the ammonia gas flow to be 50sccm and the total gas pressure to be 0.3KPa, carrying out nitridation reaction for 1h, and then naturally cooling to room temperature under the argon atmosphere to obtain the tungsten nitride nano porous film integrated electrode with the ruthenium nanoclusters loaded in a limited area.
As shown in fig. 4, an XPS spectrum of the tungsten nitride nanoporous film integrated electrode with ruthenium nanoclusters loaded in the limited domain prepared in this example is shown in fig. 4a, which is an XPS full spectrum scan of the tungsten nitride nanoporous film with ruthenium nanoclusters loaded in the limited domain, which shows that the tungsten nitride nanoporous film with ruthenium nanoclusters loaded in the limited domain contains Ru, W, N, C, and O elements, fig. 4b is a scan of Ru elements, which proves that ruthenium exists in a metal valence state, fig. 4C is a scan of W elements, fig. 4d is a scan of N elements, and W and N both are derived from tungsten nitride.
Example 5
(1) And (3) anode treatment: ultrasonically cleaning a 1 square centimeter tungsten foil by using acetone, absolute ethyl alcohol and deionized water respectively, removing organic matters on the surface, and drying by using nitrogen; using a circular tungsten foil with an exposed surface diameter of 0.5 square centimeter and an area of 0.19625 square centimeters as an anode, 0.2mol/L oxalic acid, 0.02mol/L NaF and 0.2mol/L Na2SO4The electrolyte solution (2) was anodized at a voltage of 10V for 100 minutes with a platinum sheet as a cathode. After the reaction, the sample was rinsed with flowing deionized water and nitrogen was addedAir drying to obtain anode nano porous tungsten oxide;
(2) carrying out limited loading of ruthenium nanoclusters in tungsten oxide nanopores: 2mg of RuCl3·3H2Dissolving O in 30ml of deionized water solvent, putting in a magneton, precipitating at the bottom of the solvent, putting the nano-porous tungsten oxide obtained in the step (1) in a cubic copper cage and suspending on the middle-upper part of the solvent, stirring for 6 hours at room temperature in an air atmosphere on a magnetic stirrer, transferring the solution and the nano-porous tungsten oxide to a reaction kettle with a polytetrafluoroethylene substrate, packaging, heating for 5 hours in a 200 ℃ drying oven, and then cooling to room temperature in the drying oven; then taking out the nano-porous tungsten oxide, washing with absolute ethyl alcohol and deionized water, and drying.
(3) CVD nitridation reaction: and (3) placing the nano porous tungsten oxide obtained in the step (2) in the center of a quartz tube of a CVD tube furnace, setting the furnace temperature at 500 ℃, the argon gas flow at 50sccm, the ammonia gas flow at 10sccm and the total gas pressure at 0.25KPa to perform nitridation reaction for 0.5h, and then naturally cooling to room temperature under the argon atmosphere to obtain the tungsten nitride nano porous film integrated electrode with the ruthenium nanoclusters loaded in a limited domain.
Example 6
(1) And (3) anode treatment: ultrasonically cleaning a 1 square centimeter tungsten foil by using acetone, absolute ethyl alcohol and deionized water respectively, removing organic matters on the surface, and drying by using nitrogen; using a circular tungsten foil with an exposed surface diameter of 0.5 square centimeter and an area of 0.19625 square centimeters as an anode, 0.3mol/L oxalic acid, 0.03mol/L NaF and 0.3mol/L Na2SO4The electrolyte solution (2) was anodized at a voltage of 70V for 10 minutes with a platinum sheet as a cathode. After the reaction is finished, washing a sample by using flowing deionized water, and drying by using nitrogen to obtain the anode nano-porous tungsten oxide;
(2) carrying out limited loading of ruthenium nanoclusters in tungsten oxide nanopores: 0.4mg of RuCl3·3H2Dissolving O in 8ml of deionized water solvent, putting in a magneton, precipitating at the bottom of the solvent, putting the nano-porous tungsten oxide obtained in the step (1) in a cubic copper cage and suspending on the middle-upper part of the solvent, stirring for 1h in an air atmosphere at room temperature on a magnetic stirrer, and then dissolving the obtained nano-porous tungsten oxide in the solventTransferring the solution and the nano-porous tungsten oxide into a reaction kettle with a polytetrafluoroethylene substrate, packaging, heating in a drying oven at 150 ℃ for 10h, and then, cooling to room temperature in the drying oven; then taking out the nano-porous tungsten oxide, washing with absolute ethyl alcohol and deionized water, and drying.
(3) CVD nitridation reaction: and (3) placing the nano porous tungsten oxide obtained in the step (2) in the center of a quartz tube of a CVD tube furnace, setting the furnace temperature at 900 ℃, the argon gas flow rate at 200sccm, the ammonia gas flow rate at 100sccm and the total gas pressure at 0.4KPa to perform nitridation reaction for 3 hours, and then naturally cooling to room temperature under the argon atmosphere to obtain the tungsten nitride nano porous film integrated electrode with the ruthenium nanoclusters loaded in a limited area.
Example 7
(1) And (3) anode treatment: ultrasonically cleaning a 1 square centimeter tungsten foil by using acetone, absolute ethyl alcohol and deionized water respectively, removing organic matters on the surface, and drying by using nitrogen; using a circular tungsten foil with an exposed surface diameter of 0.5 square centimeter and an area of 0.19625 square centimeters as an anode, 0.15mol/L oxalic acid, 0.01mol/L NaF and 0.1mol/L Na2SO4The electrolyte solution (2) was anodized at a voltage of 60V for 60 minutes with a platinum sheet as a cathode. After the reaction is finished, washing a sample by using flowing deionized water, and drying by using nitrogen to obtain the anode nano-porous tungsten oxide;
(2) carrying out limited loading of ruthenium nanoclusters in tungsten oxide nanopores: 1mg of RuCl3·3H2Dissolving O in 12ml of deionized water solvent, putting in a magneton, precipitating at the bottom of the solvent, putting the nano-porous tungsten oxide obtained in the step (1) in a cubic copper cage and suspending on the middle-upper part of the solvent, stirring for 3 hours at room temperature in an air atmosphere on a magnetic stirrer, transferring the solution and the nano-porous tungsten oxide to a reaction kettle with a polytetrafluoroethylene substrate, packaging, putting in a 100 ℃ drying oven, heating for 15 hours, and then cooling to room temperature in the drying oven; then taking out the nano-porous tungsten oxide, washing with absolute ethyl alcohol and deionized water, and drying.
(3) CVD nitridation reaction: and (3) placing the nano porous tungsten oxide obtained in the step (2) in the center of a quartz tube of a CVD tube furnace, setting the furnace temperature to be 800 ℃, the argon gas flow to be 100sccm, the ammonia gas flow to be 50sccm and the total gas pressure to be 0.3KPa, carrying out nitridation reaction for 1h, and then naturally cooling to room temperature under the argon atmosphere to obtain the tungsten nitride nano porous film integrated electrode with the ruthenium nanoclusters loaded in a limited area.
The application of the material obtained in example 7 in the electrochemical field is verified experimentally as follows:
testing the performance of acidic electrocatalysis hydrogen evolution:
to study the hydrogen evolution catalytic performance of the material, a three-electrode system was used for testing on an electrochemical workstation of type CHI-660E, Chen Hua, Shanghai. At 0.5M H2SO4The aqueous solution is used as electrolyte, a high-purity platinum sheet is used as a counter electrode, and Hg/Hg of the KCl solution is saturated2Cl2The electrode was used as a reference electrode, the tungsten nitride nanoporous membrane with limited loading of ruthenium nanoclusters was used as a working electrode (exposed effective area of 0.19625 square centimeters), hydrogen was bubbled for 30 minutes to remove dissolved oxygen, polarization curve measurement was performed at 50mV/s sweep rate, and all potentials were changed to standard hydrogen electrode (RHE): e(RHE)=E(SCE)+ (0.242+0.059 pH). As shown in FIG. 5a, the initial hydrogen evolution potential of the tungsten nitride nanoporous thin film integrated electrode with ruthenium nanoclusters loaded in a limited domain is about 30mV, and when the current reaches 10mA/cm2The overpotential was 65mV, as shown in FIG. 5b, which is a Tafel plot, and it can be seen that this material has a lower Tafel slope, about 48 mV/dec.
And (3) testing the performance of alkaline electrocatalysis hydrogen evolution:
to study the hydrogen evolution catalytic performance of the material, a three-electrode system was used for testing on an electrochemical workstation of type CHI-660E, Chen Hua, Shanghai. Taking 1.0M KOH aqueous solution as electrolyte, taking a high-purity platinum sheet as a counter electrode, and saturating Hg/Hg of KCl solution2Cl2The electrode was used as a reference electrode, the tungsten nitride nanoporous membrane with limited loading of ruthenium nanoclusters as a working electrode (exposed effective area of 0.19625 square centimeters), bubbled with hydrogen for 30 minutes to remove dissolved oxygen, polarization curve measurements were performed at a sweep rate of 50mV/s, and all potentials were exchanged for a standard hydrogen electrode (RHE): e(RHE)=E(SCE)+ (0.242+0.059 pH). As shown in FIG. 6a, the initial hydrogen evolution potential of the tungsten nitride nano-porous film integrated electrode with ruthenium nanoclusters supported in a limited area is about 30mV, and when the current reaches 10mA/cm2The overpotential for this time was 70mV, as shown in FIG. 6b, which is 62mV/dec compared to the material with a lower Tafel slope.
And (3) stability testing: as shown in fig. 7, the tungsten nitride nanoporous film integrated electrode with ruthenium nanoclusters loaded in a limited domain prepared in example 7 of the invention is 0.5M H saturated in hydrogen2SO4Galvanostatic stability test curves in solution and in 1M KOH solution. From fig. 7, it can be seen that the tungsten nitride nanoporous film integrated electrode with ruthenium nanoclusters supported in a limited domain prepared by the invention has almost no attenuation compared with the initial value and shows good stability after being tested for 30h and 20h under the acidic and alkaline conditions respectively under constant potential.