阅读说明：本技术 钯磷硫二维多晶材料的制备及其在电化学领域中的应用 (Preparation of palladium-phosphorus-sulfur two-dimensional polycrystalline material and application thereof in electrochemical field ) 是由 刘璞 高宏志 杨国伟 于鹏 付国帅 于 2020-12-15 设计创作，主要内容包括：本发明属于电化学技术领域,具体涉及钯磷硫二维多晶材料的制备及其在电化学领域中的应用,为开发一种性能优异的钯系催化剂材料,本发明以钯磷硫三种元素为材料,采用激光液相熔蚀技术进行激光处理,制备得到钯磷硫二维多晶材料。所制备得到的钯磷硫二维多晶材料属于一种双性催化剂,在碱性酸性条件下均具有较好的过电位,具有可以和铂基催化剂相媲美的光电催化性能,可应用在电化学领域中。(The invention belongs to the technical field of electrochemistry, in particular to preparation of a palladium-phosphorus-sulfur two-dimensional polycrystalline material and application thereof in the field of electrochemistry, and aims to develop a palladium catalyst material with excellent performance. The prepared palladium-phosphorus-sulfur two-dimensional polycrystalline material belongs to a dual-property catalyst, has better overpotential under the alkaline acidic condition, has photoelectric catalytic performance comparable to that of a platinum-based catalyst, and can be applied to the electrochemical field.)

1. A preparation method of a palladium-phosphorus-sulfur two-dimensional polycrystalline material is characterized in that three elements of palladium, phosphorus and sulfur are used as materials, laser processing is carried out by adopting a laser liquid phase ablation technology, and the palladium-phosphorus-sulfur two-dimensional polycrystalline material is prepared.

2. The preparation method of the palladium-phosphorus-sulfur two-dimensional polycrystalline material according to claim 1, characterized by comprising the following steps:

s1, dispersing palladium phosphorus sulfur powder in a mixed solution of isopropanol and water, and performing ultrasonic dispersion treatment for a certain time;

and S2, irradiating the mixed solution subjected to ultrasonic dispersion treatment by using pulse laser to perform laser treatment, and preparing the palladium-phosphorus-sulfur two-dimensional polycrystalline material.

3. The method according to claim 2, wherein the palladium-phosphorus-sulfur two-dimensional polycrystalline material is prepared by using palladium powder, phosphorus powder and sulfur powder in the palladium-phosphorus-sulfur powder in a ratio of: (0.185-0.197):(0.0567-0.0592):(0.0549-0.0557).

4. The method for preparing a palladium phosphorus sulfur two-dimensional polycrystalline material according to claim 2, wherein the concentration of the palladium phosphorus sulfur powder in the mixed solution is (0.1-0.3) mg/mL.

5. The method for preparing the palladium-phosphorus-sulfur two-dimensional polycrystalline material according to claim 2, wherein the volume ratio of isopropanol to water is (2-4): 1.

6. The method for preparing a palladium-phosphorus-sulfur two-dimensional polycrystalline material according to claim 2, wherein the frequency of ultrasonic dispersion is (45-65) kHz, the power is (40-60) W, and the time of dispersion treatment is not less than 10 min.

7. The method as claimed in claim 2, wherein the energy of the pulsed laser is 500-600mJ, the frequency is 5-15Hz, and the duration of the pulsed laser is 6-12 h.

8. The method for preparing a palladium-phosphorus-sulfur two-dimensional polycrystalline material according to claim 2, wherein a 2nm YAG laser and a 532nm holophote are used for irradiating pulse laser.

9. The palladium-phosphorus-sulfur two-dimensional polycrystalline material prepared by the preparation method of any one of claims 1 to 8.

10. Use of the palladium phosphorus sulfur two-dimensional polycrystalline material according to claim 9 in the electrochemical field.

Technical Field

The invention belongs to the technical field of electrochemistry, and particularly relates to a preparation method of a palladium-phosphorus-sulfur two-dimensional polycrystalline material and application of the palladium-phosphorus-sulfur two-dimensional polycrystalline material in the field of electrochemistry.

Background

In the field of electrocatalysis, the best catalytic material at present is platinum or a platinum-based material, and the platinum or the platinum-based catalytic material can greatly reduce the overpotential of the catalytic reaction and increase the energy conversion efficiency of hydrogen production by water electrolysis. However, platinum-based materials have long been limited to expensive price and low reserves, and many researchers now increase the activity of catalytic sites of platinum-based materials by increasing the specific surface area of the materials or alloying precious metals with other metals, thereby reducing the amount of platinum-based precious metals used.

In addition, researchers have also been working on finding non-platinum based catalysts with excellent performance. As an inexpensive alternative to platinum, palladium-based materials are a very important direction in the field of catalytic research at present, and the position of palladium metal in volcano diagram is very close to that of platinum metal, so that the palladium-based materials theoretically have very good catalytic performance. Therefore, it is feasible and necessary to develop a palladium-based catalyst material having excellent properties.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a preparation method of a palladium-phosphorus-sulfur two-dimensional polycrystalline material, and the prepared palladium-phosphorus-sulfur two-dimensional polycrystalline material is an amphoteric catalyst, has better photoelectrocatalysis performance under alkaline and acidic conditions, and can be applied to the electrochemical field.

In order to achieve the purpose, the invention adopts the technical scheme that:

a preparation method of a palladium-phosphorus-sulfur two-dimensional polycrystalline material is characterized in that three elements of palladium, phosphorus and sulfur are used as materials, laser processing is carried out by adopting a laser liquid phase ablation technology, and the palladium-phosphorus-sulfur two-dimensional polycrystalline material is prepared.

The original palladium-phosphorus-sulfur single crystal powder has almost no electrocatalytic properties due to its poor conductivity and few active sites. The material is prepared by a laser liquid phase ablation method, weak chemical bonds in the palladium phosphorus sulfur material are broken, and P elements in the palladium phosphorus sulfur material are knocked out, so that the conductivity of the palladium phosphorus sulfur material is enhanced, the number of active sites is greatly increased, and the catalytic performance of the palladium phosphorus sulfur material is greatly improved; in addition, the laser liquid phase ablation technology can improve the performance of the catalyst and can be repeatedly utilized, the efficiency of the catalytic material is maximized, and the environment-friendly catalytic reaction behavior is realized.

The prepared palladium-phosphorus-sulfur two-dimensional polycrystalline material is an amphoteric catalyst, has very good electrochemical performance under alkaline and acidic conditions, is very close to the performance of platinum, and has a Tafel slope exceeding that of platinum.

As a preferred embodiment of the present invention, the preparation of the palladium-phosphorus-sulfur two-dimensional polycrystalline material specifically comprises the following steps:

s1, dispersing palladium phosphorus sulfur powder in a mixed solution of isopropanol and water, and performing ultrasonic dispersion treatment for a certain time;

and S2, irradiating the mixed solution subjected to ultrasonic dispersion treatment by using pulse laser to perform laser treatment, and preparing the palladium-phosphorus-sulfur two-dimensional polycrystalline material.

Preferably, in the palladium phosphorus sulfur powder, the ratio of the palladium powder, the phosphorus powder and the sulfur powder is: (0.185-0.197):(0.0567-0.0592):(0.0549-0.0557). Further, the amount ratio of the palladium powder, the phosphorus powder and the sulfur powder is 0.197:0.0567:0.0549 or 0.185: 0.0592: 0.0557.

preferably, the concentration of the palladium phosphorus sulfide powder in the mixed solution is (0.1-0.3) mg/mL. Further, the concentration of the palladium phosphorus sulfur powder in the mixed solution was 0.2 mg/mL.

Preferably, the volume ratio of the isopropyl alcohol to the water is (2-4): 1. Further, the volume ratio of isopropanol to water was 3: 1.

Preferably, the frequency of ultrasonic dispersion is (45-65) kHz, the power is (40-60) W, and the time of dispersion treatment is not less than 10 min. Further, the frequency of ultrasonic dispersion was 53kHz, the power was 50W, and the time of dispersion treatment was 10 min.

Preferably, the energy of the pulse laser is 500-600mJ, the frequency is 5-15Hz, and the action time of the pulse laser is 6-12 h. Furthermore, the energy of the pulse laser is 570mJ, the frequency is 10Hz, and the acting time of the pulse laser is 9 h.

Preferably, a 2nm YAG laser and a 532nm total reflection mirror are used for irradiation of pulse laser.

The invention also provides the palladium-phosphorus-sulfur two-dimensional polycrystalline material prepared by the preparation method.

The invention also provides application of the palladium-phosphorus-sulfur two-dimensional polycrystalline material prepared by the preparation method in the electrochemical field.

The palladium-phosphorus-sulfur two-dimensional polycrystalline material prepared by the method is a dual-property catalyst, has better overpotential under alkaline acidic condition, has the photoelectric catalytic performance comparable to that of a platinum-based catalyst, solves the cost problem of the platinum-based catalyst, can be used for preparing other materials with catalytic effect to find a raw material matching system with better performance, and can even be combined with conductive hydrogel and aerogel to be applied to NH³And the catalytic decomposition of the gas has wide application value.

It should be noted that the palladium-phosphorus-sulfur two-dimensional polycrystalline material of the present invention can also be synthesized by other means, such as hydrothermal method, and obtained by changing the used compounds, such as other sulfides, selenides or nitrides. In addition, the palladium phosphorus sulfur polycrystalline material can be obtained by means of chemical vapor deposition and the like.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a preparation method of a palladium-phosphorus-sulfur two-dimensional polycrystalline material, which takes three elements of palladium, phosphorus and sulfur as materials and adopts a laser liquid phase ablation technology to carry out laser treatment to prepare the palladium-phosphorus-sulfur two-dimensional polycrystalline material. The prepared palladium-phosphorus-sulfur two-dimensional polycrystalline material is of a polycrystalline structure, belongs to a double-property catalyst, has better overpotential under alkaline and acidic conditions, has electrocatalytic performance comparable to that of a platinum-based catalyst, and can be applied to the field of electrochemistry.

Drawings

FIG. 1 is a TEM image of a palladium phosphorus sulfur two-dimensional polycrystalline material prepared in example 1;

FIG. 2 is a TEM diffraction pattern of a palladium phosphorus sulfide two-dimensional polycrystalline material prepared in example 1;

FIG. 3 is a TEM high resolution of the two-dimensional polycrystalline material of palladium, phosphorus and sulfur prepared in example 1;

FIG. 4 is a graph of the electrochemical performance of a palladium phosphorus sulfur two-dimensional polycrystalline material, a palladium phosphorus sulfur original sample, and a 50% platinum carbon catalyst in 0.5mol/L sulfuric acid;

in fig. 4, LAL PdPS: the palladium phosphorus sulfur powder after laser treatment, i.e., the palladium phosphorus sulfur two-dimensional polycrystalline material of example 1; Pt/C50%: 50% of a platinum carbon catalyst; PdPS crystal: an original palladium phosphorus sulfur bulk material; striatified PdPS: raw palladium phosphorus sulfide layer material.

FIG. 5 is a circular stability curve of electrochemical performance of a palladium phosphorus sulfur two-dimensional polycrystalline material;

FIG. 6 is a diagram showing the electrochemical performance of a palladium phosphorus sulfur two-dimensional polycrystalline material in 1mol/L potassium hydroxide;

in fig. 6, LAL PdPS: the palladium phosphorus sulfur powder after laser treatment, i.e., the palladium phosphorus sulfur two-dimensional polycrystalline material of example 1.

FIG. 7 is a Tafel slope plot of a palladium phosphorus sulfide two-dimensional polycrystalline material and a platinum carbon catalyst after laser treatment.

In fig. 7, LAL PdPS: the palladium phosphorus sulfur powder after laser treatment, i.e., the palladium phosphorus sulfur two-dimensional polycrystalline material of example 1; Pt/C50%: 50% of a platinum carbon catalyst; palladium black, Palladium black; PdPS crystal: an original palladium phosphorus sulfur bulk material; striatified PdPS: raw palladium phosphorus sulfide layer material.

Detailed Description

The following further describes the embodiments of the present invention. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The experimental procedures in the following examples were carried out by conventional methods unless otherwise specified, and the test materials used in the following examples were commercially available by conventional methods unless otherwise specified.

Example 1 preparation method of palladium-phosphorus-sulfur two-dimensional polycrystalline material

Firstly, 10mg of the mixture is mixed into a mixture with a stoichiometric ratio of 1: 1: 1 of palladium phosphorus sulfur powder (PdPS powder, Pd 0.1974g, P0.0567 g, S0.0549g) is dispersed in 50mL of mixed solution composed of IPA (isopropanol) and deionized water according to the volume ratio of 3:1, and ultrasonic dispersion is carried out for 10min at room temperature (the ultrasonic frequency is 53kHz, the power is 50W, the used equipment is an ultrasonic cleaner, the model is SK3210LHC, and the manufacturer is a Shanghai ultrasonic guide instrument); the above solution was then transferred to a 300mL glass vial and fixed on a magnetic stirring instrument. And irradiating pulse laser into the mixed solution from the glass bottle mouth by using a 532nm YAG laser and a 532nm holophote, wherein the energy of the pulse laser is 570mJ, the frequency is 10Hz, and the acting time of the pulse laser is 9h (the laser irradiation treatment is carried out by adopting laser liquid phase corrosion equipment, namely a YAG laser, SPECTRA-PHYSICS LASERS, the model is PS201), so as to obtain the palladium-phosphorus-sulfur two-dimensional polycrystalline material.

Embodiment 2 preparation method of palladium-phosphorus-sulfur two-dimensional polycrystalline material

Firstly, 10mg of the mixture is mixed into a mixture with a stoichiometric ratio of 1: 1: 1 of palladium phosphorus sulfur powder (PdPS powder, Pd 0.1974g, P0.0567 g, S0.0549g) is dispersed in 50mL of mixed solution composed of IPA (isopropanol) and deionized water according to the volume ratio of 2:1, and ultrasonic dispersion is carried out for 15min at room temperature (the ultrasonic frequency is 53kHz, the power is 50W, the used equipment is an ultrasonic cleaner, the model is SK3210LHC, and the manufacturer is a Shanghai ultrasonic guide instrument); the above solution was then transferred to a 300mL glass vial and fixed on a magnetic stirring instrument. And irradiating pulse laser into the mixed solution from the glass bottle mouth by using a 532nm YAG laser and a 532nm holophote, wherein the energy of the pulse laser is 500mJ, the frequency is 5Hz, and the acting time of the pulse laser is 6h (the laser irradiation treatment is carried out by adopting laser liquid phase corrosion equipment, namely a YAG laser, SPECTRA-PHYSICS LASERS, the model is PS201), so as to obtain the palladium-phosphorus-sulfur two-dimensional polycrystalline material.

Embodiment 3 preparation method of palladium-phosphorus-sulfur two-dimensional polycrystalline material

Firstly, 10mg of the mixture is mixed into a mixture with a stoichiometric ratio of 1: 1: 1 of palladium phosphorus sulfur powder (PdPS powder, Pd 0.185g, P0.0592 g and S0.0557g) is dispersed in 50mL of mixed solution composed of IPA (isopropanol) and deionized water according to the volume ratio of 4:1, and ultrasonic dispersion is carried out for 20min at room temperature (the ultrasonic frequency is 53kHz, the power is 50W, the used equipment is an ultrasonic cleaner, the model is SK3210LHC, and the manufacturer is a Shanghai department ultrasonic guide instrument); the above solution was then transferred to a 300mL glass vial and fixed on a magnetic stirring instrument. And irradiating pulse laser into the mixed solution from the glass bottle mouth by using a 532nm YAG laser and a 532nm holophote, wherein the energy of the pulse laser is 600mJ, the frequency is 15Hz, and the acting time of the pulse laser is 12h (the laser irradiation treatment is carried out by adopting laser liquid phase corrosion equipment, namely a YAG laser, SPECTRA-PHYSICS LASERS, the model is PS201), so as to obtain the palladium-phosphorus-sulfur two-dimensional polycrystalline material.

Experimental example 1 Transmission Electron Microscopy (TEM) analysis

The palladium phosphorus sulfur two-dimensional polycrystalline material prepared in example 1 was used as a test sample, and subjected to TEM analysis using a 300kV transmission electron microscope (FEI Tecnai G2F 30, FEI Co., U.S.A.) to obtain TEM pictures as shown in FIGS. 1 to 3.

As can be seen from the TEM image of FIG. 1, the prepared palladium-phosphorus-sulfur material is a uniformly distributed two-dimensional material; as can be seen from the TEM diffraction pattern of FIG. 2, the prepared palladium-phosphorus-sulfur material has diffraction rings, which proves that the material is a polycrystalline structure, and the material is two-dimensional as can be seen from the graph; as can be seen from the TEM high resolution image of FIG. 3, the prepared palladium-phosphorus-sulfur material has a plurality of crystal faces, which proves that the material is of a polycrystalline structure. In conclusion, the palladium-phosphorus-sulfur material prepared by the invention is a palladium-phosphorus-sulfur two-dimensional polycrystalline material.

Experimental example 2 electrochemical Performance test

The test of the electrocatalytic performance of the catalyst was carried out by a three-electrode system. The working electrode is a glassy carbon electrode loaded with palladium phosphorus sulfur material, the counter electrode is a graphite electrode, the reference electrode is a silver chloride electrode, and the electrolyte adopts 0.5M H₂SO₄Solution (pH 0.3). The specific test process comprises the following steps:

(1) drying the palladium-phosphorus-sulfur two-dimensional polycrystalline material prepared in the example 1 at the temperature of 65 ℃ for one day, adding 5mL of deionized water, adding 20 mu L of 5 wt% Nafion, and performing ultrasonic dispersion for 20min to obtain a uniform dispersion liquid;

(2) a pipette gun was used to aspirate 5. mu.L of electrode dispersion droplets onto the polished glassy carbon electrode surface (0.07065 cm)²) And naturally drying at room temperature. The electrode was used at 0.5mol/L H₂SO₄(pH 0.3) solutionElectrochemical hydrogen evolution test results are shown in fig. 4-6. Wherein the scanning rate of Linear Sweep Voltammetry (LSV) is 5 mV/S. Stability test A continuous potential cycle (relative to RHE) was selected at a sweep rate of 100mV/S over a potential window of-0.1V to-0.3V.

As can be seen from the electrochemical performance chart under the acidic condition in FIG. 4, the palladium-phosphorus-sulfur two-dimensional polycrystalline material sample is 10mA/cm²The corresponding overpotential was-37 mV versus 50% platinum on carbon at 10mA/cm²The corresponding overpotential is-33 mV. As can be seen from the cycle stability curve of the palladium phosphorus sulfur two-dimensional polycrystalline material in FIG. 5, the electrochemical performance of the palladium phosphorus sulfur two-dimensional polycrystalline material is basically unchanged after 40000 cycles of the cycle. As can be seen from the electrochemical performance chart under the alkaline condition of FIG. 6, the palladium-phosphorus-sulfur two-dimensional polycrystalline material sample is 10mA/cm²The overpotential corresponding to the time is-37 mV, and the electrocatalytic performance is very excellent. As can be seen from fig. 7, the tafel slope of the laser-treated palladium phosphorus sulfide material is 22, while the tafel slope of the platinum carbon catalyst material is 28, which shows that the tafel slope of the laser-treated material is lower.

In addition, the electrochemical performance of the palladium-phosphorus-sulfur two-dimensional polycrystalline materials prepared in the examples 2 and 3 is similar to or the same as that of the example 1.

Therefore, the palladium phosphorus sulfur two-dimensional polycrystalline material prepared by the method is an amphoteric catalyst, has very good electrochemical performance under alkaline and acidic conditions, and is very close to the performance of platinum.

The embodiments of the present invention have been described in detail, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, and the scope of protection is still within the scope of the invention.