CN105839150B - A kind of material modified preparation method of platinum - Google Patents

Abstract

The invention discloses a method for preparing a platinum modified material, which comprises the following steps: (1) Electrodeposition, preparing an electrodeposition liquid, using a graphite electrode as a prototype, and a foamed nickel substrate as a cathode, and performing electrodeposition to prepare iron/foamed nickel electrode; (2) impregnation deposition, dissolving hexachloroplatinic acid in water to prepare an impregnation deposition solution, and then put the iron/nickel foam electrode into the impregnation deposition solution for reaction; (3) chemical reduction, weigh the hydroboration Sodium or potassium borohydride solution is dissolved in water to prepare a reducing agent solution, and then the reducing agent solution is added to the immersion deposition solution of the step (2) for reduction to obtain a platinum-iron/nickel electrode, that is, a Pt-Fe/Ni electrode. The invention adopts electrodeposition, dipping deposition and chemical reduction method to prepare Pt-modified electrode Pt-Fe/Ni, not only the preparation conditions are easy to control, but also Pt and Fe are loaded on foamed nickel in nanometer shape, which improves the surface area of the original platinum electrode material , to promote the electrocatalytic activity of the electrode.

Description

A kind of preparation method of platinum modified material

technical field

The invention relates to the field of environmental protection and governance, in particular to a preparation method of a platinum modified material.

Background technique

Tetrabromobisphenol A (TBBPA) is currently the most common brominated flame retardant, widely used in building materials, synthetic fiber textiles, integrated circuit boards and plastic products. In recent years, TBBPA has been identified as a potential endocrine disrupting chemical (EDCs). Due to its refractory, accumulative and biological toxicity in the environment, it is urgent to find a rapid and efficient degradation method.

Electrochemical method is a traditional water treatment technology with promising applications due to its versatility, high energy efficiency, environmental compatibility, and easy control. Oxidative debromination is difficult due to the high electronegativity of the bromine atom in tetrabromobisphenol A. Therefore, the use of electrocatalytic reduction in electrochemistry to degrade TBBPA has become a new idea. The mechanism of electrocatalytic reduction is mainly: in the presence of _H2 , the catalytic metal adsorbs _H2 to form [H] in the adsorbed state, and the [H] in the adsorbed state breaks RX (X=F, Cl, Br) to achieve Dehalogenation.

Pt can not only promote the hydrogen evolution reaction, but also absorb active hydrogen atoms, which is beneficial to the electrocatalytic reduction and degradation of TBBPA. However, since platinum is a relatively rare noble metal, the cost of directly using platinum as an electrode is relatively high, which is not conducive to the subsequent expansion of use.

The information disclosed in this Background section is only for enhancing the understanding of the general background of the present invention and should not be taken as an acknowledgment or any form of suggestion that the information constitutes the prior art that is already known to those skilled in the art.

Contents of the invention

The object of the present invention is to provide a kind of preparation method of platinum modified material, the platinum modified material prepared by this method is applicable to the platinum modified electrode of electrocatalytic reduction of tetrabromobisphenol A, reduces the usage amount of Pt in the Pt electrode , improve the hydrogen production and hydrogen storage capacity of the system, provide sufficient hydrogen source for the electrocatalytic reduction of tetrabromobisphenol A, ensure the rapid and efficient electrocatalytic reduction degradation of tetrabromobisphenol A, and at the same time, due to the independent hydrogen production capacity of the system Strong, can avoid the potential danger when adding H2. .

In order to achieve the above object, the invention provides a kind of preparation method of platinum modified material, comprising the following steps:

(1) Electrodeposition, preparation of electrodeposition solution, graphite electrode as prototype, foamed nickel substrate as cathode, electrodeposited to prepare iron/foamed nickel electrode;

(2) Immersion deposition, dissolving hexachloroplatinic acid (H ₂ PtCl ₆ ) in water to prepare an immersion deposition solution, and then putting the iron/foam nickel electrode into the immersion deposition solution to react;

(3) Chemical reduction, taking sodium borohydride (NaBH ₄ ) or potassium borohydride (KBH ₄ ) solution and dissolving it in water to obtain a reducing agent solution, and then adding the reducing agent solution to the dipping deposition solution in step (2) Reduction, to obtain platinum-iron/nickel electrode, that is, Pt-Fe/Ni electrode.

Preferably, in the above scheme, the electrodeposition solution includes: ferrous sulfate heptahydrate (FeSO ₄ ·7H ₂ O), sodium sulfate (Na ₂ SO ₄ ) and cetyltrimethylammonium bromide (CTAB) , the molar concentration ratio of ferrous sulfate heptahydrate, sodium sulfate and cetyltrimethylammonium bromide is 5-25:1-15:1.

Preferably, in the above-mentioned scheme, the nickel foam substrate is pretreated before electrodeposition, including the following steps: first, the nickel foam substrate is acid-treated to remove the surface oxide layer, then ultrasonically treated in ethanol, and then placed in Sonication in water.

Preferably, in the above scheme, the acid used for foam nickel acid treatment is sulfuric acid.

Preferably, in the above scheme, the electrodeposition current in the step (1) is 10mA, and the electrodeposition time is 20-40min.

Preferably, in the above scheme, in the step (2), the iron/foam nickel electrode is placed in the immersion deposition solution, and then placed in an oscillating device for reaction.

Preferably, in the above solution, the oscillation device is a water bath oscillation, the oscillation temperature is 30-50°C, the oscillation speed is 90-130r/min, and the oscillation time is 4-8h.

Preferably, in the above scheme, the hexachloroplatinum hydrogen acid solution obtained after the hexachloroplatinum hydrogen acid is dissolved in water in the step (2) has a concentration of 0.0001-0.001mol/L.

Preferably, in the above scheme, the pH value of the reducing agent solution added in the step (3) is 11-13.

Preferably, in the above scheme, the reduction time in the step (3) is 30-60min.

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

(1) The present invention prepares Pt-modified electrode Pt-Fe/Ni by electrodeposition, dipping deposition and chemical reduction, not only the preparation conditions are easy to control, but also Pt and Fe are loaded on foamed nickel in nanometer shape, which improves the efficiency of the original platinum electrode. The surface area of the material promotes the electrocatalytic activity of the electrode.

(2) The addition of transition metal Fe to Pt enhances the electrocatalytic activity of the Pt electrode material on the one hand, and on the other hand reduces the amount of platinum used and the production cost, which is conducive to popularization and use.

(3) Nickel foam is used as the base material of noble metal Pt. On the one hand, the surface area of Pt modified electrode is increased due to the strong rigidity and network structure of nickel foam, which is beneficial to mass transfer and improves the electrochemical performance of the electrode. activity; on the other hand, the use of Pt modified electrode electrocatalytic reduction to degrade tetrabromobisphenol A can solve the problem that the binary catalyst formed by Pt is difficult to recycle and cause secondary pollution.

(4) Re-reduction of the formed Pt-Fe/Ni foam electrode by NaBH ₄ or KBH ₄ enables platinum ions in other valence states to be impregnated on the surface of the electrode to form nanoparticles loaded on the electrode, and at the same time strengthen the reduction of iron , reducing the oxidation of nano-iron, which is beneficial to the electrocatalytic reduction degradation of tetrabromobisphenol A, and also improves the utilization rate of platinum salt.

Description of drawings

Fig. 1 is the SEM figure of untreated foamed nickel electrode;

Fig. 2 is the SEM figure that makes Pt-Fe/Ni electrode after the preparation method of the present invention is processed;

Fig. 3 is an EDS diagram of a Pt-Fe/Ni electrode prepared after being processed by the preparation method of the present invention.

Fig. 4 is the electrochemical performance test diagram of the Pt-Fe/Ni electrode prepared after the preparation method of Example 1 and Example 2.

Fig. 5 is an electrochemical performance test chart of a platinum-modified electrode prepared after being processed by the preparation methods of Example 3 and Example 4.

detailed description

The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations thereof such as "includes" or "includes" and the like will be understood to include the stated elements or constituents, and not Other elements or other components are not excluded.

Example 1

The preparation process of Pt-Fe/Ni modified electrode material comprises the following steps:

(1) Substrate pretreatment: First, cut the foamed nickel base material into a size of 3cm×5cm, and place the cut foamed nickel base material in 1mol/L H ₂ SO ₄ for 5 minutes to remove the oxide layer on the surface ; Subsequently, the acid-treated nickel foam matrix is ultrasonically 15min in ethanol and deionized water successively to remove organic matter on the surface;

(2) Electrodeposition: prepare 100mL electrodeposition solution, the concentrations of FeSO ₄ 7H ₂ O, Na ₂ SO ₄ and CTAB in the solution are 0.015mol/L, 0.01mol/L and 0.001mol/L respectively, with inert graphite The electrode is the anode, and the pretreated nickel foam base material is the cathode. At room temperature, the Fe/foam nickel electrode is prepared by electroplating at a constant current of 10mA for 30min;

(3) Immersion deposition: use water as solvent, dissolve H ₂ PtCl ₆ in it, prepare 0.02mol/L H ₂ PtCl ₆ stock solution, store at 4°C; take 1.5mL of the stock solution and dilute it to 50mL, and make a concentration of 0.0006mol/L impregnation deposition solution; place the Fe/nickel foam electrode in the above impregnation deposition solution, and shake for 4 hours at a constant temperature of 30°C and a constant speed of 130r/min;

(4) Chemical reduction: Dissolve NaBH ₄ , which is 6 times the total amount of platinum and iron, in 10 mL of deionized water, and adjust its pH value to 12; drop its reducing agent solution into the dipping deposition solution for 30 min, A Pt-Fe/Ni modified electrode was obtained.

Fig. 1 is the scanning electron micrograph of foamed nickel base material, foamed nickel surface is smooth, is a kind of three-dimensional skeleton structure, has larger pore volume; Fig. 2 is the scanning that embodiment 1 makes Pt-Fe/Ni modified electrode Electron micrographs, the nanoparticles on the nickel foam skeleton are denser, indicating that both Pt and Fe nanoparticles are loaded on the surface.

As shown in Figure 3, it is the EDS diagram of the Pt-Fe/Ni modified electrode prepared in Example 1. This diagram can show that there are four elements O, Pt, Fe, and Ni in the platinum modified electrode, and the EDS diagram is qualitatively illustrated Pt and Fe have been successfully loaded onto the surface of Pt-Fe/Ni electrodes.

Under the condition of 0.5mol/LH ₂ SO ₄ solution, in the case of a three-electrode system with a platinum electrode as the counter electrode, a saturated calomel electrode as the reference electrode and a Pt-Fe/Ni modified electrode as the working electrode, the determination of Pt-Fe Electrocatalytic performance of Ni/Ni modified electrodes. As shown in FIG. 4 , the electrochemical performance test chart of the Pt-Fe/Ni electrode prepared in Example 1 is shown.

Example 2

The preparation process of Pt-Fe/Ni modified electrode material comprises the following steps:

(1) Substrate pretreatment: First, cut the foamed nickel base material into a size of 3cm×5cm, and place the cut foamed nickel base material in 1mol/L H ₂ SO ₄ for 5 minutes to remove the oxide layer on the surface ; Subsequently, the acid-treated nickel foam matrix is ultrasonically 15min in ethanol and deionized water successively to remove organic matter on the surface;

(2) Electrodeposition: prepare 100mL electrodeposition solution, the concentrations of FeSO ₄ 7H ₂ O, Na ₂ SO ₄ and CTAB in the solution are 0.015mol/L, 0.01mol/L and 0.001mol/L respectively, with inert graphite The electrode is the anode, and the pretreated nickel foam base material is the cathode. At room temperature, the Fe/foam nickel electrode is prepared by electroplating at a constant current of 10mA for 30min;

(3) Immersion deposition: use water as solvent, dissolve H ₂ PtCl ₆ in it, prepare 0.02mol/L H ₂ PtCl ₆ stock solution, store at 4°C; take 0.75mL stock solution and dilute it to 50mL, and make a concentration of 0.0003mol/L impregnation deposition solution; place the Fe/nickel foam electrode in the above impregnation deposition solution, and shake for 4 hours at a constant temperature of 30°C and a constant speed of 130r/min;

(4) Chemical reduction: Dissolve NaBH ₄ , which is 6 times the total amount of platinum and iron, in 10 mL of deionized water, and adjust its pH value to 12; drop its reducing agent solution into the dipping deposition solution for 30 min, A Pt-Fe/Ni modified electrode was obtained.

Under the condition of 0.5mol/LH ₂ SO ₄ solution, in the case of a three-electrode system with a platinum electrode as the counter electrode, a saturated calomel electrode as the reference electrode and a Pt-Fe/Ni modified electrode as the working electrode, the determination of Pt-Fe Electrocatalytic performance of Ni/Ni modified electrodes. As shown in FIG. 4 , the electrochemical performance test chart of the Pt-Fe/Ni electrode prepared in Example 1 is shown.

Example 3

The preparation process of Pt-Fe/Ni modified electrode material comprises the following steps:

(1) Substrate pretreatment: First, cut the foamed nickel base material into a size of 3cm×5cm, and place the cut foamed nickel base material in 1mol/L H ₂ SO ₄ for 5 minutes to remove the oxide layer on the surface ; Subsequently, the acid-treated nickel foam matrix is ultrasonically 15min in ethanol and deionized water successively to remove organic matter on the surface;

(2) Electrodeposition: prepare 100mL electrodeposition solution, the concentrations of FeSO ₄ 7H ₂ O, Na ₂ SO ₄ and CTAB in the solution are 0.015mol/L, 0.01mol/L and 0.001mol/L respectively, with inert graphite The electrode is the anode, and the pretreated nickel foam base material is the cathode. At room temperature, the Fe/foam nickel electrode is prepared by electroplating at a constant current of 10mA for 30min;

(3) Immersion deposition: use water as solvent, dissolve H ₂ PtCl ₆ in it, prepare 0.02mol/L H ₂ PtCl ₆ stock solution, store at 4°C; take 1.5mL of the stock solution and dilute it to 50mL, and make a concentration of 0.0006mol/L impregnation deposition solution; place the Fe/nickel foam electrode in the above impregnation deposition solution, and vibrate for 8 hours at a constant temperature of 50°C and a speed of 90r/min to obtain a Pt-Fe/Ni modified electrode.

Example 4

The preparation process of Pt/Ni modified electrode material comprises the following steps:

(1) Substrate pretreatment: First, cut the foamed nickel base material into a size of 3cm×5cm, and place the cut foamed nickel base material in 1mol/L H ₂ SO ₄ for 5 minutes to remove the oxide layer on the surface ; Subsequently, the acid-treated nickel foam matrix is ultrasonically 15min in ethanol and deionized water successively to remove organic matter on the surface;

(2) Immersion deposition: use water as solvent, dissolve H ₂ PtCl ₆ in it, prepare 0.02mol/L H ₂ PtCl ₆ stock solution, store at 4°C _{; 6} The concentration is 0.0006mol/L, and the concentration of CTAB is 0.001mol/L respectively; place the pretreated foamed nickel electrode in the above dipping deposition solution, and shake for 4 hours at a constant temperature of 30°C and a constant speed of 130r/min;

(3) Chemical reduction: Dissolve NaBH ₄ , which is 6 times the amount of platinum substance, in 10 mL of deionized water, and adjust its pH value to 12; drop its reducing agent solution into the dipping deposition solution for 30 min to obtain Pt/ Ni modified electrode.

Under the conditions of initial tetrabromobisphenol A concentration of 20mg/L and initial pH=3, a platinum electrode is used as a counter electrode, a saturated calomel electrode is used as a reference electrode and a Pt-Fe/nickel foam electrode or a Pt/nickel foam electrode is In the case of the three-electrode system of the working electrode, the electrocatalytic performance of the platinum-modified electrode for tetrabromobisphenol A was determined. In this method, the platinum modified electrodes prepared in Example 3 and Example 4 were tested. As shown in Figure 5, the electrochemical impedance spectroscopy of Pt/Ni electrode and Pt-Fe/Ni electrode in the presence of TBBPA. The electrical impedance of the Pt-Fe/Ni electrode is smaller than that of the Pt/Ni electrode, and the smaller the electrical impedance, the faster the electron transfer rate on the electrode surface. It can be concluded from the electrochemical impedance spectroscopy that the addition of Fe nanoparticles can reduce the impedance of the electrode and accelerate the migration rate of electrons on the electrode surface.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling others skilled in the art to make and use various exemplary embodiments of the invention, as well as various Choose and change. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims (9)

1. a preparation method of platinum modified material, is characterized in that, comprises the following steps: (1) Electrodeposition, preparation of electrodeposition liquid, with graphite electrode as anode, nickel foam base material as cathode, carry out electrodeposition to prepare iron/foam nickel electrode; (2) Impregnation deposition, dissolving hexachloroplatinum hydrogen acid in water to prepare an impregnation deposition solution, and then putting the iron/foam nickel electrode into the dipping deposition solution to react; in the step (2), hexachloroplatinum hydrogen After the acid is dissolved in water, the concentration of the hexachloroplatinum hydrogen acid solution is 0.0001-0.001mol/L; (3) Chemical reduction, taking sodium borohydride or potassium borohydride and dissolving it in water to obtain a reducing agent solution, then adding the reducing agent solution to the dipping deposition solution of the step (2) for reduction to obtain a platinum-iron/nickel electrode . 2. the preparation method of platinum modified material according to claim 1, is characterized in that, described electrodeposition liquid comprises: ferrous sulfate heptahydrate, sodium sulfate and cetyltrimethylammonium bromide, heptahydrate The molar concentration ratio of ferrous sulfate, sodium sulfate and cetyltrimethylammonium bromide is 5-25:1-15:1. 3. the preparation method of platinum modified material according to claim 1 is characterized in that, before carrying out electro-deposition nickel foam base material is carried out pretreatment, comprises the following steps, at first nickel foam base material is carried out acid treatment and removes surface The oxide layer was then sonicated in ethanol and then placed in water for sonication. 4. the preparation method of platinum-modified material according to claim 3 is characterized in that, the acid used for foam nickel acid treatment is sulfuric acid. 5. The preparation method of platinum-modified material according to claim 1, characterized in that the electrodeposition electric current in the step (1) is 10mA, and the electrodeposition time is 20-40min. 6. The preparation method of platinum-modified material according to claim 1, characterized in that, in the step (2), the iron/foam nickel electrode is placed in the immersion deposition solution, and then placed in an oscillating device for reaction. 7. The preparation method of platinum modified material according to claim 6, characterized in that, the oscillation device is a water bath oscillation, the oscillation temperature is 30-50°C, the oscillation rate is 90-130r/min, the oscillation time 4-8h. 8. The preparation method of platinum-modified material according to claim 1, characterized in that, the pH value of the reducing agent solution added in the step (3) is 11-13. 9. The preparation method of platinum-modified material according to claim 1, characterized in that, the reduction time in the step (3) is 30-60min.