A preparation method of a chemical palladium plating on a medical stone ceramic

Abstract

The application provides a method for electroless plating of palladium on a ceramic carrier of medical stone. The method aims to solve the technical problem of uniform and firm plating of palladium on a natural silicate ceramic carrier with a porous and complex surface. The specific steps include: preparing a fine powder of natural medical stone, pressing the powder into a tablet, and baking the tablet at 1100 o C to obtain a ceramic carrier of medical stone. The ceramic carrier of medical stone is pretreated by pickling, sensitization and activation, and then immersed in a specific electroless plating solution composed of PdCl2, NH3H2O, NH4Cl and NaH2PO2 at pH=10, and plated at a constant temperature of 45-55 ℃ for 60 min. After plating, the ceramic carrier of medical stone is taken out, washed with deionized water, dried and baked at 500 ℃ for 2 h to obtain a palladium plating layer on the surface of the ceramic carrier of medical stone. The method can obtain a palladium plating layer with uniformity, flatness and strong adhesion on the surface of the ceramic carrier of medical stone, and has the advantages of simple process equipment, high utilization rate of palladium, short preparation period and low cost.

Description

Technical Field

[0001] This invention belongs to the field of inorganic non-metallic material surface modification technology, and relates to a process for depositing palladium metal on the surface of natural porous silicate ceramic—maifan stone ceramic—by chemical plating. Background Technology

[0002] Maifan stone, composed of various minerals, is a natural silicate mineral with a rich microporous structure, large specific surface area, and no toxic side effects on plants and animals. It has wide applications in environmental protection and health fields. To endow maifan stone ceramics with physicochemical functions (such as conductivity, catalytic activity, and antibacterial properties), a functional metal layer is often introduced onto its surface. Palladium (Pd), as a precious metal, possesses excellent chemical stability and functional properties.

[0003] Currently, common methods for loading palladium onto ceramic substrates include impregnation and physical vapor deposition (PVD). Impregnation often requires high-temperature calcination and reduction, resulting in complex processes, high energy consumption, and difficulty in controlling metal dispersion and adhesion. PVD, on the other hand, involves expensive equipment and struggles to form uniform coatings on complex, porous internal surfaces. Chemical plating offers advantages such as simple equipment, uniform coatings, and applicability to complex-shaped workpieces. However, for natural ceramics with complex compositions and unique surface properties, such as maifan stone, there is currently no mature and efficient chemical palladium plating process. Therefore, developing a chemical palladium plating method specifically designed for maifan stone ceramic substrates that offers stable processing, high-quality coatings, and lower costs has significant practical application value. Summary of the Invention

[0004] In view of this, the present invention provides a method for chemically plating palladium onto maifanite ceramics.

[0005] This invention provides a method for preparing palladium by chemical plating on maifanite ceramics, the specific steps of which include the following:

[0006] (1) Weigh 1 g of maifan stone and process it into fine powder through crushing, ball milling and spray drying. Press it into tablets through a φ10mm tablet press and fire it at 1100 ℃ to make maifan stone ceramic carrier. Soak the maifan stone ceramic carrier in 10wt% HCl solution for 10 minutes, take it out and wash it with deionized water, and dry it at 120 ℃ for 1 hour.

[0007] (2) The carrier treated in step (1) is immersed in a sensitization solution of 10 g / L SnCl2 and 30 mL / L HCl for sensitization, and then washed with deionized water. The sensitized carrier is then immersed in an activation solution of 0.1 g / L PdCl2 and 3 mL / L HCl for 10 minutes for activation, and then washed with deionized water.

[0008] (3) Immerse the maifan stone ceramic carrier treated in step (2) into a chemical palladium plating solution with NaH2PO2 as the reducing agent and pH=10, and perform plating at a constant temperature of 45-55 ℃ for 60 min. After plating, take it out, wash it with deionized water, dry it and calcine it to obtain a palladium coating on the surface of the maifan stone ceramic. The chemical palladium plating solution contains the following components at the following concentrations: PdCl2 3 g / L, NH3·H2O 60-200 mL / L, NH4Cl 10-50 g / L, NaH2PO2 5-30 g / L, HCl 4 ml / L.

[0009] (4) The sensitization time in step (2) is 10 minutes.

[0010] (5) The roasting temperature in step (3) is 500 ℃ and the roasting time is 2 h. Detailed Implementation

[0011] This invention provides a method for preparing palladium by chemical plating on maifanite ceramics, comprising the following steps:

[0012] Natural maifan stone is ground into a fine powder, then compressed into tablets (1100). o C was used to prepare a maifanite ceramic carrier. The maifanite ceramic carrier was subjected to acid washing, sensitization and activation pretreatment; then it was immersed in a specific chemical plating solution with pH=10 composed of PdCl2, NH3·H2O, NH4Cl and NaH2PO2, and plating was carried out at a constant temperature of 45-55 ℃ for 60 min. After plating, it was taken out, washed with deionized water, dried and calcined at 500 ℃ for 2 h, thus obtaining a palladium coating on the surface of the maifanite ceramic.

[0013] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments thereof. Example

[0014] (1) Weigh 1 g of maifan stone and process it into fine powder through crushing, ball milling and spray drying. Press it into tablets with a height of 1.15 mm using a φ10 mm tablet press. Then, fire it at 1100 ℃ to make a maifan stone ceramic carrier. Soak the maifan stone ceramic carrier in 10 wt% HCl solution for 10 minutes, take it out and wash it with deionized water, and dry it at 120 ℃ for 1 hour.

[0015] (2) Immerse the carrier treated in step (1) in a sensitization solution of 10 g / L SnCl2 and 30 mL / L HCl for 10 min, then remove and wash with deionized water. Immerse the sensitized carrier in an activation solution of 0.1 g / L PdCl2 and 3 mL / L HCl for 10 min, then remove and wash with deionized water.

[0016] (3) Immerse the maifan stone ceramic carrier treated in step (2) into a chemical palladium plating solution with pH=10 using NaH2PO2 as a reducing agent, and perform plating at a constant temperature of 45-55 ℃ for 60 min. After plating, remove the carrier, wash it with deionized water, and dry it. The chemical palladium plating solution contains the following components at the following concentrations: PdCl2 3 g / L, NH3·H2O 100 mL / L, NH4Cl 40 g / L, NaH2PO2 20 g / L, and HCl 4 ml / L.

[0017] (4) The dried carrier is calcined at 500 °C for 2 h. Example

[0018] The preparation steps in this embodiment are basically the same as those in Example 1, except that the chemical palladium plating solution in step (3) contains 60 mL / L NH3·H2O, 10 g / L NH4Cl, and 5 g / L NaH2PO2. Example

[0019] The preparation steps in this embodiment are basically the same as those in Example 1, except that the chemical palladium plating solution in step (3) contains 200 mL / L NH3·H2O, 50 g / L NH4Cl, and 30 g / L NaH2PO2.

[0020] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. For those skilled in the art, any obvious changes or substitutions that can be made without departing from the essence of the technical solution of the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

Claims

1. A method for preparing palladium by chemical plating on maifanite ceramics, characterized in that, Includes the following steps: Step A: Weigh 1 g of maifan stone, and after crushing, ball milling, and spray drying, produce fine powder. Press the powder into tablets using a φ10mm tablet press, and then fire the tablets at 1100℃ to form a maifan stone ceramic carrier. Immerse the maifan stone ceramic carrier in a 10wt% HCl solution for 10 minutes, then remove it, wash it with deionized water, and dry it at 120℃ for 1 hour. Step B: Immerse the carrier treated in Step A in a sensitization solution of 10 g / L SnCl2 and 30 mL / L HCl for sensitization, then remove and wash with deionized water. Next, immerse the sensitized carrier in an activation solution of 0.1 g / L PdCl2 and 3 mL / L HCl for 10 minutes, then remove and wash with deionized water. Step C: Immerse the maifan stone ceramic carrier treated in Step B into a palladium electroless plating solution with NaH2PO2 as the reducing agent and pH=10. Plating is carried out at a constant temperature of 45-55 ℃ for 60 min. After plating, the carrier is removed, washed with deionized water, dried, and calcined to obtain a palladium coating on the surface of the maifan stone ceramic. The palladium electroless plating solution contains the following components at the following concentrations: PdCl2 3 g / L, NH3·H2O 60-200 mL / L, NH4Cl 10-50 g / L, NaH2PO2 5-30 g / L, and HCl 4 ml / L.

2. The preparation method according to claim 1, characterized in that, The roasting temperature in step C is 500 °C.

3. The preparation method according to claim 2, characterized in that, The roasting time is 2 hours.

4. The preparation method according to claim 1, characterized in that, The sensitization time in step B is 10 minutes.

5. The preparation method according to claim 1, characterized in that, The tablets described in step A are pressed into tablets using a φ10mm tablet press, with a tablet height of 1.15mm.