Preparation of palladium chloride modified glassy carbon electrode and application of palladium chloride modified glassy carbon electrode in field of borax determination
By modifying the nanopalladium structural material of glass carbon electrodes, establishing a three-electrode system, and using cyclic voltammetry to detect the content of borax, the problems of insufficient sensitivity and complex operation of the existing detection methods are solved, and the detection effect of high sensitivity and simple operation is achieved.
Patent Information
- Application Number
- CN202311635506.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-01
- Publication Date
- 2025-06-03
AI Technical Summary
The existing borax detection methods have problems such as insufficient sensitivity and complex operation, making it difficult to effectively detect the content of borax.
A glass carbon electrode was modified with nanopalladium structural material, and a three-electrode system was established. The peak current was recorded within a specific potential range by cyclic voltammetry, and a standard curve was established to determine the content of borax.
It realizes high sensitivity detection of borax, has high selectivity and ease of operation, and can accurately determine the content of borax.
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Figure CN120084854A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electrochemical analysis and detection, and particularly to the development of a new electrode for the determination of borax. Background Art
[0002] Borax is a very important boron-containing mineral and boron compound. It is usually a white powder containing colorless crystals and is easily soluble in water. Borax has a wide range of uses. It can be used as a cleaner, cosmetics, insecticide, and can also be used to prepare buffer solutions and other boron compounds. Commercially available borax is often partially weathered. Borax is highly toxic, and many countries in the world have banned it as a food additive. If the human body ingests too much boron, it will cause cumulative poisoning of multiple organs. Currently, the commonly used detection methods for borax are the test paper method and the spectrophotometry method. Summary of the Invention
[0003] The purpose of the present invention is to modify a glassy carbon electrode with a nano-palladium structural material to establish a new method for the determination of borax.
[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows: It includes a three-electrode system composed of a modified electrode as the working electrode, an Ag / AgCl electrode as the reference electrode, and a platinum wire as the auxiliary electrode. The modified electrode is a nano-palladium structural material. The three-electrode system is placed in the treated borax, and within the potential range of -0.8 to 0.3 V, the cyclic voltammogram curve of the peak current is recorded at a scanning rate of 50 mV / s within the concentration range of 0.05 to 5.0 mg / mL. The specific operation steps include:
[0005] (1) Preparation of the sensor: Pretreatment of the glassy carbon electrode, purification and carboxylation of carbon nanotubes, and electrodeposition to prepare a carbon nanotube / palladium nanostructure composite electrode material;
[0006] (2) Optimization of the determination conditions: Influence of pH, influence of deposition cycles;
[0007] (3) Establishment of the working curve: The working electrode is a self-made modified electrode (GCE matrix), the reference electrode is an Ag / AgCl electrode, and the counter electrode is a platinum wire electrode, forming a three-electrode system; The three-electrode system is placed in the treated borax standard solution within the concentration range of 0.05 to 5.0 mg / mL, and the peak current is recorded under the optimal experimental conditions to establish a standard curve equation of the peak current with the standard product concentration as the variable, as shown in Figure 6 .
[0008] (4) Determination of actual samples: The samples are adjusted to a range of 0.05 - 5.0 mg / mL, and the three - electrode system is placed in the prepared borax sample solution under the same test conditions as those for establishing the standard curve. Cyclic voltammetry is used to scan and record the peak current, and then the content of borax in the sample is calculated by substituting into the above - mentioned standard curve equation.
[0009] The present invention utilizes the good conductivity of the glassy carbon electrode and combines it with the properties of palladium chloride to prepare an electrode with high sensitivity to borax. Then, by optimizing parameters such as deposition time and the pH of the bottom solution, an electrochemical analysis method with high selectivity, high sensitivity, and easy operation for borax is obtained, and this method is applied to the determination of actual samples. Brief Description of the Drawings
[0010] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.
[0011] Appendix Figure 1 Sulfuric acid activation curve of the bare electrode
[0012] Appendix Figure 2 Curve of the electrodeposition process of nano - palladium
[0013] Appendix Figure 3 Cyclic voltammetry curves of different electrodes in a 5 mg / mL borax solution
[0014] Appendix Figure 4 Optimization curve of pH
[0015] Appendix Figure 5 Optimization curve of deposition time
[0016] Appendix Figure 6 CV diagrams of borax solutions with different concentrations
[0017] Appendix Figure 7 Interference resistance test diagram Detailed Description of the Specific Embodiments
[0018] To achieve the purpose of the invention, the technical solution adopted by the present invention is as follows: It includes a three - electrode system composed of a glassy carbon electrode or a modified electrode as the working electrode, an Ag / AgCl electrode as the reference electrode, and a platinum wire as the auxiliary electrode. The modified electrode is a nano - palladium structural material.
[0019] Pretreatment of the glassy carbon electrode: Take the glassy carbon electrode and polish it on metallographic sandpaper (3000#), and then polish it successively with 1.0, 0.3, and 0.05 μm of Al 2 O 3 powder on dry and wet suede pads, ultrasonically clean it thoroughly with deionized distilled water, absolute ethanol, and deionized distilled water in sequence, and then place the electrode in 0.1 mol / L of H 2 SO4 In the solution, at a scanning rate of 50 mV / s, in the potential range of -0.9 to +0.1 V, scan for 15 cycles using cyclic voltammetry (CV). Take out the electrode activated by sulfuric acid, rinse it thoroughly with distilled water, and place it in 0.01 mol / L K 3 [Fe(CN) 6 In the solution, at a scanning rate of 50 mV / s, in the potential range of -0.2 to +0.6 V, scan using cyclic voltammetry (CV) until stable.
[0020] Electrodeposition preparation of carbon nanotube / palladium nanostructure composite electrode material: The electrodeposition preparation is carried out using a CS300 type electrochemical workstation, adopting a three-electrode system: a glassy carbon electrode (GCE) as the working electrode, a platinum wire as the counter electrode, and an Ag / AgCl electrode as the reference electrode. Place the glassy carbon electrode in a 0.5 mmol / L palladium chloride solution, with a scanning rate of 25 mV / s, a potential range of -0.4 to +0.8 V, and perform cyclic voltammetry cycling scans for 15 cycles. Then take out the electrode, rinse the electrode surface with deionized distilled water, and dry it.
[0021] Appendix Figure 1 Sulfuric acid activation diagram of bare electrode. Take a glassy carbon electrode and polish it on a metallographic sandpaper (3000#), and then successively polish it with 1.0, 0.3, and 0.05 μm Al 2 O 3 powder on dry and wet suede pads in turn. Ultrasonically clean it thoroughly with deionized distilled water, absolute ethanol, and deionized distilled water in turn. Then place the electrode in 0.1 mol / L H 2 SO 4 solution, at a scanning rate of 50 mV / s, in the potential range of -0.9 to +0.1 V, scan for 15 cycles using cyclic voltammetry (CV). Take out the electrode activated by sulfuric acid and rinse it thoroughly with distilled water.
[0022] Appendix Figure 2 Cyclic voltammetry (CV) diagram of nano-palladium electrodeposition
[0023] Appendix Figure 3 Cyclic voltammograms of different electrodes in a 5 mg / mL borax solution. A borax solution with a concentration of 5 mg / mL prepared with deionized water, a blank glassy carbon electrode, and a palladium chloride modified electrode. In the potential range of -0.8 to 0.3 V, under the scanning rate condition of 50 mV / s, perform cyclic voltammetry scans of different electrodes. Reversible oxidation peaks and reduction peaks appear on the palladium chloride modified electrode, indicating that the electrode reaction process of borax is reversible.
[0024] Appendix Figure 4 Acidity influence diagram
[0025] Appendix Figure 5Optimization curve of deposition turns. The deposition turns are set to 5 turns, 10 turns, 15 turns, and 20 turns respectively. When the deposition turns are 15 turns, the catalytic current will reach the maximum value.
[0026] Appendix Figure 6 、 Figure 7 CV diagrams and standard curve diagrams of borax solutions with different concentrations. Borax solutions with concentrations of 0.1 mg / mL, 0.25 mg / mL, 0.5 mg / mL, 0.75 mg / mL, and 1.0 mg / mL are prepared with PBS buffer solution with pH = 7. Under the optimal experimental conditions, the modified electrodes of borax solutions with different concentrations are measured by cyclic voltammetry, and the oxidation peaks of the voltammetric characteristic diagrams of the modified electrodes with palladium chloride in borax solutions with different concentrations are used. The standard curve is made using Origin software. The standard curve equation is Y = 3×10 -5 X - 4×10 -6 A,R 2 = 0.921.
[0027] Figure 8 Anti-interference test diagram. Nitrate ions, sulfate ions, and phosphate ions are respectively added to the prepared borax solution, and it is scanned with a modified electrode of palladium chloride. It shows that the palladium chloride electrode has good anti-interference performance.
Claims
1. Preparation of Palladium Chloride Modified Electrode for Borax Determination and Its Determination Method, Characterized in that, The glassy carbon electrode is the matrix electrode modified with palladium chloride. The electrode preparation is characterized by using the electro-deposition method: placing the pretreated glassy carbon electrode in a 0.5 mmol / L palladium chloride solution, performing cyclic voltammetry scanning for 15 cycles in a three-electrode system with a platinum wire electrode as the counter electrode and an Ag / AgCl electrode as the reference electrode, then taking out the electrode, rinsing the electrode surface with deionized distilled water, and drying.
2. The electrode for borax determination and its determination method according to claim 1, wherein the electrode preparation is characterized in that when using a glassy carbon electrode as the working electrode, a platinum wire electrode as the counter electrode, an Ag / AgCl electrode as the reference electrode, and a 0.5 mmol / L palladium chloride solution as the modification solution, the scanning speed is set at 25 mV / s and the potential range is -0.4 to +0.8 V.
3. The borax determination electrode and its determination method according to claim 1, wherein the determination method is characterized in that the palladium chloride modified glassy carbon electrode is placed in a borax standard solution with a concentration of 0.05 - 5.0 mg / mL, and the peak current of the cyclic voltammogram is recorded at a scanning rate of 50 mV / s between -0.8 V and 0.3 V with PBS having a pH of 7 - 9 as the buffer solution, and the sample content is calculated using the standard curve equation. The standard curve equation is Y = 3×10 -5 X - 4×10 -6 A, and the correlation coefficient R 2 = 0.921.