CN113186562B - Ir @ SC nanoparticle catalyst and preparation and application thereof - Google Patents

Abstract

The invention discloses an Ir @ SC nanoparticle catalyst. The invention discloses a preparation method of the Ir @ SC nanoparticle catalyst, which comprises the following steps: mixing a sulfur-containing organic ligand and iridium chloride trihydrate, adding a solvent, refluxing and heating overnight in an inert gas atmosphere, cooling, centrifuging, washing, and drying to obtain orange yellow powder; and (3) loading the orange powder into a quartz boat, putting the quartz boat into a tube furnace again, introducing inert gas flow, heating, and calcining at constant temperature to obtain the Ir @ SC nanoparticle catalyst. The invention discloses application of the Ir @ SC nanoparticle catalyst in preparation of hydrogen and active chlorine disinfectant by electrolyzing seawater with high current density and high stability. The invention discloses a working electrode for electrolyzing seawater to prepare hydrogen and active chlorine disinfectant with high current density and high stability and a manufacturing method thereof. The invention discloses a method for preparing hydrogen and active chlorine by electrolyzing seawater through sunlight power generation.

Description

A kind of Ir@SC nanoparticle catalyst and its preparation and application

technical field

The invention relates to the technical field of catalysts, in particular to an Ir@SC nanoparticle catalyst and its preparation and application.

Background technique

Hydrogen production by electrolysis of water is one of the effective ways to realize the transformation of the global energy structure to a clean and low-carbon environment. At present, the electrolytic water hydrogen production technology mainly uses the alkaline electrolysis system and the proton exchange membrane electrolysis system, but both of these two technical routes rely on high-purity fresh water as the water source, which puts huge pressure on the fresh water resources that people depend on for survival. On the other hand, Shanghai is rich in water resources. If renewable energy such as solar energy and wind energy are used to generate electricity, and seawater is directly electrolyzed to produce hydrogen, it can not only reduce the pressure on fresh water resources, but also alleviate the current energy and environmental crisis. However, due to the presence of chloride ions and various cations such as calcium and magnesium in seawater, the electrode materials suffer from severe corrosion as the electrolysis proceeds. huge challenge.

In the process of electrolyzing seawater to produce hydrogen, the oxidation of the anode can oxidize water into oxygen, and can also oxidize chloride ions in seawater into oxidative active chlorine (chlorine gas, hypochlorous acid, etc.). If a suitable catalyst is developed to enable the anode to oxidize chlorine ions to active chlorine with high selectivity, the seawater electrolyte dissolved in active chlorine can be used as a disinfectant in the fields of disinfection in medical and health institutions and various public places. In addition, in the marine industry and military, the disinfectant containing active chlorine can be used as a decontamination agent for algae and microorganisms in the ocean to avoid damage to equipment by marine organisms attached to the surface of marine industrial production equipment and military ships. Moreover, the use of solar power for seawater electrolysis can realize distributed and on-site production of disinfectant, which can be directly used for the protection of offshore equipment, and can also reduce the risks caused by traditional transportation and storage of disinfectants. Therefore, the use of anodic oxidation to produce hydrogen from electrolyzed water has high practical application value. However, the competitive reaction of anode oxygen uptake requires researchers to develop catalytic materials for efficient and selective production of active chlorine.

Based on reducing the cost of catalytic materials, the development of a high-efficiency electrocatalyst that can simultaneously electrolyze seawater to produce hydrogen and disinfectant is of great significance for the efficient utilization of seawater resources, but it is also facing major challenges. In addition, the use of solar power to produce hydrogen and disinfectant by dual-function electrolysis of seawater to achieve industrial applications and generate economic benefits also requires simple electrolysis equipment and catalytic materials capable of dual-function electrolysis of seawater at low potential, high current density, and high stability.

Contents of the invention

The purpose of the present invention is to solve the shortcomings in the prior art, and propose an Ir@SC nanoparticle catalyst and its preparation and application. In the Ir@SC nanoparticle catalyst obtained in the present invention, the metal iridium is uniformly supported in the sulfur-doped modified carbon, and the metal iridium is confined between at least two layers of sulfur-doped modified carbon materials; the obtained Ir@SC nanoparticle catalyst It can be used as an electrocatalyst with high current density and high stability to prepare hydrogen and active chlorine disinfectant by double-functional electrolysis of seawater at low potential; at the same time, the invention can use solar energy to generate electricity, and electrolyze the two electrodes of the solar panel and the catalytic material Equipment connection, preliminarily realized the distributed utilization of solar energy to electrolyze seawater to prepare hydrogen and disinfectant.

A method for preparing an Ir@SC nanoparticle catalyst, comprising the steps of:

S1. Mix the sulfur-containing organic ligand and iridium chloride trihydrate, add a solvent, heat under reflux overnight in an inert gas atmosphere, cool, centrifuge, wash, and dry to obtain an orange-yellow powder;

S2. Put the orange-yellow powder in a quartz boat and place it in a tube furnace, introduce an inert gas flow, raise the temperature to 700-1000° C., and calcine at a constant temperature for 10-120 minutes to obtain an Ir@SC nanoparticle catalyst.

The invention uses a simple chemical coordination method to form an iridium metal complex between a sulfur-containing organic ligand and iridium chloride trihydrate, controls the calcination conditions, and prepares an Ir@SC nanoparticle catalyst with uniform size and good dispersion.

The obtained Ir@SC nanoparticle catalyst was characterized by means of XRD and TEM, and the results showed that metal iridium was uniformly supported in sulfur-doped modified carbon, and metal iridium was confined between at least two layers of sulfur-doped modified carbon materials. between.

Preferably, in S1, the sulfur-containing organic ligand is or benzothiophene, dibenzothiophene, 2-phenylbenzothiazole, 3-(3-acrylate methyl)benzothiophene, 5,6,7, At least one of 8-tetrahydrobenzothiophene phosphinimine, methionine, cystine, and cysteine, preferably 2-phenylbenzothiazole.

Preferably, in S1, the mass ratio of 2-phenylbenzothiazole to iridium chloride trihydrate is 9-11:6-8.

Preferably, in S1, the solvent is obtained by mixing ethylene glycol monoethyl ether and water at a volume ratio of 1-5:1-3.

Preferably, in S1, after the solid product is collected by centrifugation, it is washed with water, ethanol and n-hexane respectively.

Preferably, in S1, vacuum drying is used for drying, the drying temperature is 30-60° C., and the drying time is 10-20 hours.

Preferably, in S2, the heating rate is 2-10°C/min.

Preferably, the inert gas is argon.

An Ir@SC nanoparticle catalyst, which is prepared by the above-mentioned preparation method of the Ir@SC nanoparticle catalyst.

The above-mentioned Ir@SC nanoparticle catalyst was used as a catalyst for the electrolysis of seawater to produce hydrogen and active chlorine.

A method for making a working electrode for electrolyzing seawater to produce hydrogen and active chlorine. The above-mentioned Ir@SC nanoparticle catalyst is dispersed in a mixed solution, and then evenly coated on the surface of a carbon cloth and dried.

Preferably, the mixed solution is obtained by mixing absolute ethanol, deionized water, and naphthol in a volume ratio of 1.1-1.7:0.2-0.8:0.03-0.08.

Preferably, the mass volume ratio (mg/mL) of the Ir@SC nanoparticle catalyst to the mixed solution is 1.0-1.7:1.

Preferably, the coating amount (mg/cm ² ) of the Ir@SC nanoparticle catalyst on the surface of the carbon cloth is 0.10-0.18:0.245-0.375.

A working electrode for electrolyzing seawater to produce hydrogen and active chlorine is prepared by the above-mentioned working electrode manufacturing method for electrolyzing seawater to produce hydrogen and active chlorine.

A method for preparing hydrogen and active chlorine by electrolyzing seawater, using the above-mentioned working electrode as a cathode and an anode, and using an H-type electrolyzer for electrolysis.

Specifically, an Ag/AgCl electrode was used as a reference electrode to form a three-electrode system, and an H-shaped electrolytic cell was used to conduct electrolysis under the electric energy provided by the electrochemical workstation.

The linear sweep voltammetry (LSV) was used to explore the electrocatalytic activity of the catalyst, and the stability of the catalyst was demonstrated by measuring the change of the current density with time at a fixed potential and the Faradaic efficiency of hydrogen generation by the potentiostatic method. Collect the electrolyte in the anode chamber after electrolysis at constant potential for a certain period of time, measure the concentration of active chlorine in it by iodometric method, and use it to kill bacteria test and detect its bactericidal effect.

Specifically, the above-mentioned electrochemical workstation is replaced with a solar panel, and the two poles of the solar panel are directly connected to the cathode and anode of the H-shaped electrolytic cell to form a two-electrode system, and the seawater is electrolyzed under the condition of outdoor sunlight.

Under the catalysis of sulfur-doped carbon-coated iridium particles of the electrode material, the cathode chamber and anode chamber of the H-type electrolyzer generate hydrogen gas and active chlorine disinfectant respectively, and initially realize the preparation of hydrogen gas and disinfectant by electrolyzing seawater using light energy distribution.

Compared with the prior art, the present invention has the following beneficial effects:

1. The Ir@SC nanoparticle catalyst obtained in the present invention has uniform size and small particle size, metal iridium is evenly supported in sulfur-doped modified carbon, and metal iridium is confined between at least two layers of sulfur-doped modified carbon materials; Moreover, the synthesis method is simple, a large amount of synthesis can be realized, and it has broad application prospects in actual large-scale industrial applications.

2. When the Ir@SC nanoparticle catalyst obtained in the present invention is used as an electrocatalyst for dual-functional electrolysis of seawater to prepare hydrogen and disinfectant, it exhibits superior activity and stability. In the process of seawater electrolysis, when the applied overpotential is 0.5V vs RHE, the current density can reach 1000mA/cm ² , and it can be maintained stably for hundreds of hours, and the Faradaic efficiency of hydrogen evolution is maintained above 95%. At the same time, the active chlorine produced by the anode can show a highly efficient bactericidal effect. The catalytic material provided by the invention can efficiently utilize seawater resources and has high practical application value.

3. The present invention realizes the joint assembly of solar panels and electrolysis equipment, and performs dual-function electrolysis of seawater through outdoor solar power generation to simultaneously prepare hydrogen and disinfectant. This strategy of using clean and renewable energy for distributed production of hydrogen energy and disinfectant will promote the development of new energy, medical and health, and maritime military industries.

Description of drawings

Figure 1 is an optical photo of the mass synthesis of the Ir@SC nanoparticle catalyst obtained in Example 3.

Fig. 2 is an X-ray diffraction (XRD) pattern of the Ir@SC nanoparticle catalyst obtained in Example 3.

3 is an X-ray photoelectron spectroscopy (XPS) diagram of the Ir@SC nanoparticle catalyst obtained in Example 3.

Fig. 4 is a transmission electron microscope (TEM) photo of the Ir@SC nanoparticle catalyst obtained in Example 3, wherein Fig. 4a is a low-resolution TEM photo, and Fig. 4b is a particle size distribution diagram of metallic iridium particles.

Figure 5 is the LSV diagram of the electrode obtained in Example 4 in seawater electrolyte in Example 5.

Fig. 6 is the current density versus time curve and the Faradaic efficiency of the electrode obtained in Example 4 in the seawater electrolyte in Example 5.

Figure 7 is an optical photograph of the qualitative detection of active chlorine produced in the electrolyte in the anode chamber after seawater electrolysis by chromogenic method.

Figure 8 is a schematic diagram of the actual operation of hydrogen evolution in seawater under sunlight using the electrode obtained in Example 4 in Example 5.

In the above figure, Ir@SC is used to represent the sulfur-doped carbon-coated iridium nanoparticles obtained in Example 3.

detailed description

The present invention will be further explained below in conjunction with specific embodiments.

The chemical reagents used in the present invention are all analytically pure 2-phenylbenzothiazole, iridium chloride trihydrate, and ethylene glycol monoethyl ether, and the purity of the argon used is 99.999%.

The carbon cloth was purchased from Carbon Energy Carbon Cloth in Taiwan, China.

The seawater is selected from the Lianyungang area of China.

The bacteria Escherichia coli, Staphylococcus aureus and Candida albicans were all isolated and identified by the Institute of Health Science and Technology, Institute of Physical Science and Information Technology, Anhui University.

Example 1

A method for preparing an Ir@SC nanoparticle catalyst, comprising the steps of:

S1. Mix 9g of 2-phenylbenzothiazole and 8g of iridium chloride trihydrate, add to the solvent obtained by mixing ethylene glycol monoethyl ether and water at a volume ratio of 1:3, and reflux in an argon atmosphere After heating overnight, cool down, collect the solid product by centrifugation, wash three times with water, ethanol and n-hexane respectively, and vacuum dry at 60°C for 10 hours to obtain an orange-yellow powder;

S2. Put the orange-yellow powder in a quartz boat and place it in a tube furnace, introduce an argon gas flow, raise the temperature to 700°C at a heating rate of 10°C/min, and calcine at a constant temperature for 120min to obtain an Ir@SC nanoparticle catalyst .

Example 2

A method for preparing an Ir@SC nanoparticle catalyst, comprising the steps of:

S1. Mix 11g of 2-phenylbenzothiazole and 6g of iridium chloride trihydrate, add to the solvent obtained by mixing ethylene glycol monoethyl ether and water at a volume ratio of 5:1, and reflux in an argon atmosphere After heating overnight, cool down, collect the solid product by centrifugation, wash three times with water, ethanol and n-hexane respectively, and dry in vacuum at 30°C for 20 hours to obtain an orange-yellow powder;

S2. Put the orange-yellow powder in a quartz boat and place it in a tube furnace, introduce an argon gas flow, raise the temperature to 1000°C at a heating rate of 2°C/min, and calcine at a constant temperature for 10 minutes to obtain an Ir@SC nanoparticle catalyst .

Example 3

A method for preparing an Ir@SC nanoparticle catalyst, comprising the steps of:

S1. Weigh 10g of 2-phenylbenzothiazole and 7g of iridium chloride trihydrate into a three-necked flask, add a mixed solution of ethylene glycol monoethyl ether and water (3:1, v/v), and place in an Ar gas atmosphere , after heating under reflux overnight, cooled to room temperature to obtain a large amount of orange-yellow solid product; the solid product was collected by centrifugation, washed with water, ethanol and n-hexane respectively for 3 times, and dried in a vacuum oven at 40°C for 12 hours.

S2. The orange-yellow powder obtained after drying was packed in a quartz boat and then placed in a tube furnace. In the Ar flow, the temperature was raised to 900°C at a rate of 6°C/min, and the temperature was calcined for 45min to obtain Ir@SC. nanoparticle catalyst.

As shown in the optical photo of Figure 1: a large amount of catalysts can be obtained by increasing the raw materials used in the present invention, which shows that the method of the present invention is simple and can realize a large amount of synthesis.

As shown in Figure 2, using XRD to analyze the phase of the Ir@SC nanoparticle catalyst obtained in Example 3, the obtained diffraction peaks can correspond one-to-one with the metal iridium whose card number is JCPDS: 87-0715, indicating that the present invention synthesized The material is iridium metal.

According to the full spectrum of XPS (as shown in Figure 3), it can be seen that the iridium particles wrapped by carbon contain Ir, S, and C elements, indicating that the carbon material obtained in the present invention is a sulfur-doped modified carbon material, that is, a sulfur-doped carbon-wrapped Iridium nanoparticle material.

According to the low-resolution TEM photo (as shown in Figure 4a), it can be seen that: iridium nanoparticles are uniformly dispersed on the two-dimensional graphitic carbon, and the average size is less than 3nm (as shown in Figure 4b).

Example 4

Weigh 1.5 mg of the Ir@SC nanoparticle catalyst obtained in Example 3 and disperse it in 1 mL (the volume ratio of absolute ethanol: deionized water: naphthol is 1.5:0.45:0.05) mixed solution, and ultrasonically disperse for 30 minutes to obtain a uniformly dispersed slurry , use a pipette gun with a volume range of 1.0 mL to take 0.1 mL of uniformly dispersed slurry, and drop-coat it on the surface of a carbon cloth with an area of 0.5 cm × 0.65 cm in 10 times. The carbon cloth coated with the catalyst is dried and used as an electrode to electrolyze seawater.

Example 5

The electrode obtained in Example 4 was used as the cathode and the anode at the same time, and the Ag/AgCl electrode was used as the reference electrode to form a three-electrode system. The H-type electrolytic cell was used to perform the dual-function electrolytic seawater test under the electric energy provided by the electrochemical workstation.

LSV was used to explore the electrocatalytic activity of the catalyst, and the stability of the catalyst was illustrated by measuring the change of current density with time at a fixed potential and the Faraday efficiency of hydrogen generation by the potentiostatic method.

As shown in the LSV test results in Figure 5, when the Ir@SC nanoparticle catalyst obtained in Example 3 is used for bifunctional electrolysis of seawater, the overpotential required for the current density to reach 10mA/ ^cm2 is only 0.12V vs RHE, lower than Commercial Pt/C. Moreover, when the overpotential is 0.50V vs RHE, the current density is as high as 1000mA/cm ² , which can realize the electrolysis effect of low voltage and high current.

The test results of the current density versus time curve under constant potential (as shown in Figure 6) show that: when the Ir@SC nanoparticle catalyst obtained in Example 3 electrolyzes seawater, it can maintain a high current density of 1000mA/ ^cm2 for 130h, and the hydrogen evolution Faradaic efficiency Maintaining more than 95%, it has high practical application value and industrial application prospect.

Collect the electrolyte in the anode chamber after electrolysis for 60 minutes at -0.5V vs RHE constant potential, and qualitatively determine the electrolyte in the anode chamber of electrolytic seawater through the color development process of the colorless KI solution that can be oxidized by active chlorine into an orange-yellow I ^3- solution Whether there is active chlorine generation. Observe the color changes of non-electrolyzed seawater, non-electrolyzed seawater+KI, electrolyzed seawater+KI and non-electrolyzed seawater+NaClO+KI solutions respectively. As shown in the test results in Figure 7, only when KI is added to the electrolyzed seawater and the non-electrolyzed seawater with NaClO added, the color of the solution changes from colorless to orange, which confirms the electrolyte in the anode electrolyzer during the electrolysis process. There is generation of active chlorine.

Collect the electrolyte in the anode chamber after 10h and 20h of electrolysis at -0.5V vs RHE constant potential, and measure the concentration of active chlorine in it by iodometric method. The steps are as follows:

Immediately after the completion of the chronoamperometry, the anode seawater electrolyte was poured into an iodine bottle containing a large excess (~100×) of KI and _H2SO4 ( _0.5wt %), and then 1wt% starch solution was added, and the solution became Turn blue, and finally titrate with calibrated Na ₂ S ₂ O ₃ solution (0.1mol/L) until it disappears, record the consumption of Na ₂ S ₂ O ₃ solution, measure the active chlorine concentration three times, and take the average value. The results showed that the concentrations of active chlorine produced by electrolysis for 10h and 20h under the constant potential of -0.5V vs RHE were 1670ppm and 3251ppm, respectively.

Then the electrolyte in the anode chamber after electrolysis for 10 hours was diluted with water to 1/10, and then the bactericidal effect on Escherichia coli, Staphylococcus aureus and Candida albicans was tested respectively. The results are shown in the table below:

The above table shows the test results of the bactericidal rate of active chlorine disinfectant on Escherichia coli, Staphylococcus aureus and Candida albicans for 30 minutes (wherein, the control group did not add any disinfectant, and the sample group added electrolytic seawater active chlorine disinfectant ).

The results show that the preparation of active chlorine disinfectant by electrolysis of seawater has the characteristics of high efficiency and broad spectrum, low cost, safety and environmental protection in terms of disinfection function.

Example 6

The electrode obtained in Example 4 is simultaneously used as the cathode and anode of the H-type electrolytic cell, and the two poles of the solar panel are directly connected to the cathode and the anode of the H-type electrolytic cell to form a two-electrode system, and the seawater is electrolyzed under outdoor sunlight conditions. Under the catalysis of the electrode material, the cathode chamber and the anode chamber of the H-type electrolyzer generate hydrogen gas and active chlorine disinfectant, respectively, and initially realize the preparation of hydrogen gas and disinfectant by electrolyzing seawater with distributed light energy.

As shown in Figure 8, using solar power to provide electric energy, the solar panel and the two-electrode electrolysis equipment are assembled together, and a large number of bubbles are clearly seen on the surface of the cathode electrode under outdoor light conditions, which proves that the present invention successfully realizes solar power electrolysis of seawater.

Example 7

The implementation steps are the same as in Example 3, the difference is that in S1, 2-phenylbenzothiazole is changed to methionine, and other conditions remain unchanged, and the obtained results are close to those obtained in Example 3.

Example 8

The implementation steps are the same as in Example 4, the difference is that: use a pipette gun to drop-coat on the carbon cloth and change it to a spray gun to spray the conductive glass surface, and other conditions remain unchanged, and the obtained results are close to the results obtained in Example 4.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (9)

1. A method for preparing an Ir@SC nanoparticle catalyst, comprising the steps of: S1. Mix the sulfur-containing organic ligand and iridium chloride trihydrate, add a solvent, heat under reflux overnight in an inert gas atmosphere, cool, centrifuge, wash, and dry to obtain an orange-yellow powder; S2. Put the orange-yellow powder in a quartz boat and place it in a tube furnace, introduce an inert gas flow, raise the temperature to 700-1000°C, and calcine at a constant temperature for 10-120min to obtain an Ir@SC nanoparticle catalyst; The iridium metal complex precursor was synthesized by chemical coordination, and then the Ir@SC nanoparticle catalyst was obtained by calcination. In the obtained Ir@SC nanoparticle catalyst, metal iridium was uniformly supported in sulfur-doped modified carbon, and metal iridium confined between at least two layers of sulfur-doped modified carbon material. 2. The preparation method of Ir@SC nanoparticle catalyst according to claim 1, characterized in that, in S1, the sulfur-containing organic ligands are benzothiophene, dibenzothiophene, 2-phenylbenzothiazole, 3- At least one of (3-methylacrylate)benzothiophene, 5,6,7,8-tetrahydrobenzothiophene phosphinimine, methionine, cystine, and cysteine. 3. The preparation method of Ir@SC nanoparticle catalyst according to claim 1, characterized in that, in S1, the mass ratio of 2-phenylbenzothiazole and iridium chloride trihydrate is 9-11:6-8; The solvent is obtained by mixing ethylene glycol monoethyl ether and water at a volume ratio of 1-5:1-3. 4. The preparation method of Ir@SC nanoparticle catalyst according to claim 1, characterized in that, in S2, the calcining gas is argon, and the heating rate is 2-10°C/min. 5. An Ir@SC nanoparticle catalyst, characterized in that it is prepared by the preparation method of the Ir@SC nanoparticle catalyst according to any one of claims 1-4. 6. An Ir@SC nanoparticle catalyst as claimed in claim 5 is used as a catalyst for high current density and high stability electrolysis of seawater to produce hydrogen and active chlorine disinfectant. 7. A method for making a working electrode for high current density and high stability electrolysis of seawater to produce hydrogen and active chlorine, characterized in that the Ir@SC nanoparticle catalyst according to claim 6 is dispersed in the mixed solution, and then Apply evenly on the surface of carbon cloth and dry. 8. A working electrode for producing hydrogen and active chlorine by electrolysis of seawater for solar power generation, characterized in that it is produced by the working electrode production method for producing hydrogen and active chlorine disinfectant by electrolysis of seawater according to claim 7 , and all electrical energy comes from solar power generation. 9. A method for producing hydrogen and active chlorine disinfectant by electrolysis of seawater by solar power generation, characterized in that, the working electrode according to claim 8 is used as a cathode and an anode, and an H-type electrolyzer is used for electrolysis.

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