阅读说明：本技术 一种以柔性纸为基底的镍磷纳米材料及其制备方法和应用 (Nickel-phosphorus nano material with flexible paper as substrate and preparation method and application thereof ) 是由 许鑫华 谷一帆 郑丽婷 于 2019-09-23 设计创作，主要内容包括：本发明提供一种以柔性纸为基底的镍磷纳米材料及其制备方法和应用,以柔性纤维素纸为基底,采用溶液浸泡和化学镀的方法制备了镍磷纸,并且通过调整化学镀液的酸碱度和浓度,能够得到具有不同形貌的纳米花、纳米片、纳米线微球和微球的镍磷纳米材料。采用简单的溶液浸泡和化学镀的方法制备了镍磷纸,实验步骤简单,实验条件温和,可用于大规模工业生产,具有实际应用的潜力；通过调整化学镀液的酸碱度和浓度,得到了具有不同形貌的镍磷纳米材料,如纳米花、纳米片、纳米线微球和微球等,镍磷纳米材料赋予纤维素纸导电性,同时由于其高催化活性而对尿素具有潜在的敏感性,为制造非酶尿素传感器提供了可能。(The invention provides a nickel-phosphorus nano material with flexible paper as a substrate and a preparation method and application thereof. The nickel-phosphorus paper is prepared by adopting a simple solution soaking and chemical plating method, the experimental steps are simple, the experimental conditions are mild, and the nickel-phosphorus paper can be used for large-scale industrial production and has the potential of practical application; the nickel-phosphorus nano material with different shapes, such as nanoflower, nanosheet, nanowire microsphere and microsphere, is obtained by adjusting the pH value and concentration of the chemical plating solution, and the nickel-phosphorus nano material endows the cellulose paper with conductivity, has potential sensitivity to urea due to high catalytic activity and provides possibility for manufacturing a non-enzymatic urea sensor.)

1. A nickel-phosphorus nano material taking flexible paper as a substrate is characterized in that: the method comprises the following steps:

step 1, soaking cellulose paper into SnCl₂Adding into HCl mixed water solution for 10-40min, taking out, cleaning, and drying to obtain Sn²⁺Activated cellulose paper of which SnCl₂The concentration of the aqueous solution of (A) is 0.03-0.15mol/L, and the concentration of the aqueous solution of HCl is 0.05-0.30 mol/L;

step 2, Sn obtained in the step 1²⁺Soaking activated cellulose paper in PdCl₂And (3) adding the solution into a mixed aqueous solution of HCl for 20-40min, taking out, cleaning and drying to obtain the cellulose paper with palladium adhered on the surface, wherein PdCl is₂The concentration of the aqueous solution of (A) is 0.8-1.2m mol/L, and the concentration of the aqueous solution of HCl is 0.04-0.1 mol/L;

step 3, immersing the cellulose paper with palladium adhered on the surface prepared in the step 2 into NiCl₂、Na₃C₆H₆O₇、NH₄Cl and NaH₂PO₂In the formed plating solution, the temperature is kept at 70-90 ℃, the pH value of the plating solution is adjusted by ammonia water solution to be kept at 7-8, after 20-40min of reaction, the plating solution is taken out, cleaned and dried, and the nickel-phosphorus nano material taking flexible paper as a substrate is obtained, wherein NiCl is used as the substrate₂、Na₃C₆H₆O₇、NH₄Cl and NaH₂PO₂The mass ratio of (3-5) to (5-7) to (3-6) to (0.5-1.8).

2. The nickel-phosphorus nanometer material taking flexible paper as a substrate according to claim 1, is characterized in that: in step 1, SnCl₂The concentration of the aqueous solution is 0.05-0.1mol/L, the concentration of the aqueous solution of HCl is 0.1-0.25mol/L, and the soaking time is 20-30 min.

3. The nickel-phosphorus nanometer material taking flexible paper as a substrate according to claim 1, is characterized in that: in step 2, PdCl₂The concentration of the aqueous solution is 0.8-1.2m mol/L, the concentration of the aqueous solution of HCl is 0.04-0.1mol/L, the soaking time is 25-30min, the drying temperature is 50-60 ℃, and the drying time is 0.5-2 h.

4. The nickel-phosphorus nanometer material taking flexible paper as a substrate according to claim 1, is characterized in that: in step 3, NiCl₂、Na₃C₆H₆O₇、NH₄Cl and NaH₂PO₂The mass ratio of (4-5) to (6-7) to (4-6) to (0.6-1.8), the drying temperature is 55-65 ℃, and the drying time is 0.5-2 h.

5. A method for preparing nickel-phosphorus nano material by using flexible paper as a substrate is characterized by comprising the following steps: the method comprises the following steps:

step 1, soaking cellulose paper into SnCl₂Adding into HCl mixed water solution for 10-40min, taking out, cleaning, and drying to obtain Sn²⁺Activated cellulose paper of which SnCl₂The concentration of the aqueous solution of (A) is 0.03-0.15mol/L, and the concentration of the aqueous solution of HCl is 0.05-0.30 mol/L;

step 2, Sn obtained in the step 1²⁺Soaking activated cellulose paper in PdCl₂And (3) adding the solution into a mixed aqueous solution of HCl for 20-40min, taking out, cleaning and drying to obtain the cellulose paper with palladium adhered on the surface, wherein PdCl is₂The concentration of the aqueous solution of (A) is 0.8-1.2m mol/L, and the concentration of the aqueous solution of HCl is 0.04-0.1 mol/L;

step 3, immersing the cellulose paper with palladium adhered on the surface prepared in the step 2 into NiCl₂、Na₃C₆H₆O₇、NH₄Cl and NaH₂PO₂In the formed plating solution, the temperature is kept at 70-90 ℃, the pH value of the plating solution is adjusted by ammonia water solution to be kept at 7-8, after 20-40min of reaction, the plating solution is taken out, cleaned and dried, and the nickel-phosphorus nano material taking flexible paper as a substrate is obtained, wherein NiCl is used as the substrate₂、Na₃C₆H₆O₇、NH₄Cl and NaH₂PO₂The mass ratio of (3-5) to (5-7) to (3-6) to (0.5-1.2).

6. The method for preparing the nickel-phosphorus nano material by taking the flexible paper as the substrate according to claim 1, which is characterized by comprising the following steps: in step 1, SnCl₂The concentration of the aqueous solution is 0.05-0.1mol/L, the concentration of the aqueous solution of HCl is 0.1-0.25mol/L, and the soaking time is 20-30 min.

7. The method for preparing the nickel-phosphorus nano material by taking the flexible paper as the substrate according to claim 1, which is characterized by comprising the following steps: in step 2, PdCl₂The concentration of the aqueous solution of (A) is 0.8-1.2m mol/L, the concentration of the aqueous solution of HCl is 0.04-0.1mol/L, and the aqueous solution is soakedThe time is 25-30min, the drying temperature is 50-60 ℃, and the drying time is 0.5-2 h.

8. The method for preparing the nickel-phosphorus nano material by taking the flexible paper as the substrate according to claim 1, which is characterized by comprising the following steps: in step 3, NiCl₂、Na₃C₆H₆O₇、NH₄Cl and NaH₂PO₂The mass ratio of (4-5) to (6-7) to (4-6) to (0.6-1.2), the drying temperature is 55-65 ℃, and the drying time is 0.5-2 h.

9. Use of a flexible paper-based nickel-phosphorus nanomaterial according to any one of claims 1 to 4 in a non-enzymatic urea sensor.

10. Use according to claim 9, characterized in that: the paper electrode made of nickel-phosphorus nano material and taking flexible paper as a substrate has the best electrochemical performance in a low concentration range (0-1mm), and the sensitivity is 682-685 mu A mm^-1cm^-2The electrochemical performance is best in a low concentration range (0-1mm), and the sensitivity is 1135-^-1cm^-2The high concentration range (1-11mm), the lowest detection limit is 11-15 μm, and the shortest response time is 2-4 s.

Technical Field

The invention relates to the technical field of urea sensors, in particular to a nickel-phosphorus nano material taking flexible paper as a substrate and a preparation method and application thereof.

Background

Urea plays a key role in assessing various metabolic disorders, as abnormalities in human urea levels are often associated with cardiac metabolic disorders, chronic kidney disease, unipolar and renal failure. In addition, the detection of urea also has important scientific significance and application prospect in food science and environmental industry. At present, urea is detected by a plurality of methods, such as ultraviolet-visible spectroscopy, infrared spectroscopy, liquid chromatography-mass spectrometry, fluorescence method, surface plasmon resonance method and the like, but the application of the urea sensor requires that the urea sensor is silicon. The method is simple and easy to use, low in cost, convenient to carry and high in detection speed, and the methods cannot be realized. Therefore, the electrochemical sensor has the characteristics of fast response and high sensitivity, and has attracted much attention in recent years.

Electrochemical urea sensors can be divided into two categories: enzyme-based urea sensors and non-enzyme-based urea sensors. Enzyme-based urea biosensors based on electrochemical reactions of enzymes and urea have been extensively studied. However, the major disadvantage of poor stability of the enzyme remains difficult to overcome due to its biological nature. In addition, the inherent disadvantages of enzymes under limited working conditions, such as heavy metal ions, magnetic nanoparticles and thermal inactivation, also prevent the use of enzyme sensors. To address these problems, many non-enzymatic urea sensors based on electrocatalytic reactions have been developed in recent years. The core of constructing the non-enzymatic urea sensor is to select a modified material with catalytic performance. Therefore, we studied nanomaterials reported in the literature to have direct catalytic activity on urea, including Nobel metals, transition metal materials such as Ni, alloying materials such as Ni-Co, metal oxide and hydroxide materials such as NiO and Ni (OH)₂And a composite material. Such as graphene polyaniline. Compared with the traditional Nobel metal material, the transition metal and the oxide and hydroxide materials thereof have low price and are not easy to be poisonedWidely used as catalytic materials. Among them, the nickel-based material is almost the most popular catalyst because it is inexpensive and has excellent stability and catalytic activity.

In addition, with the rapid development of flexible devices, flexible and wearable sensors have attracted great attention. Compared with rigid silicon materials and plastic base materials, the cellulose paper as a everywhere visible daily use article has the advantages of obvious flexibility, light weight, no deformation, low price, porous structure, environmental protection and the like. Therefore, because of its attractive functionality, it has been extensively studied because it is used as a substrate for microfluidic paper-based analytical devices (μ -pads) manufactured by Whitesides Group. The conductive paper-based current collector is made by coating conductive fillers on a conductive layer or growing noble metals in situ on the surface of porous cellulose fibers, and has remarkable electrochemical properties and paper-based electrons. Integrated circuits have gained widespread attention in the energy storage field, point of care testing, light emitting diodes, biofuel cells and transistors. There are also many paper-based sensors, but most of these studies are microfluidic, in order to care for the spot, and no one sees continuous detection.

Disclosure of Invention

The invention overcomes the defects in the prior art, provides the nickel-phosphorus nano material taking the flexible paper as the substrate and the preparation method and the application thereof, adopts the simple method of solution soaking and chemical plating to prepare the nickel-phosphorus paper, has simple experimental steps and mild experimental conditions, can be used for large-scale industrial production, and has the potential of practical application; the nickel-phosphorus nano material with different shapes, such as nanoflower, nanosheet, nanowire microsphere and microsphere, is obtained by adjusting the pH value and concentration of the chemical plating solution, and the nickel-phosphorus nano material endows the cellulose paper with conductivity, has potential sensitivity to urea due to high catalytic activity and provides possibility for manufacturing a non-enzymatic urea sensor.

The purpose of the invention is realized by the following technical scheme.

A nickel-phosphorus nano material with flexible paper as a substrate and a preparation method thereof are carried out according to the following steps:

step 1, mixing the fiberImmersing the cellulose paper in SnCl₂Adding into HCl mixed water solution for 10-40min, taking out, cleaning, and drying to obtain Sn²⁺Activated cellulose paper of which SnCl₂The concentration of the aqueous solution of (A) is 0.03-0.15mol/L, and the concentration of the aqueous solution of HCl is 0.05-0.30 mol/L;

step 2, Sn obtained in the step 1²⁺Soaking activated cellulose paper in PdCl₂And (3) adding the solution into a mixed aqueous solution of HCl for 20-40min, taking out, cleaning and drying to obtain the cellulose paper with palladium adhered on the surface, wherein PdCl is₂The concentration of the aqueous solution of (A) is 0.8-1.2mmol/L, and the concentration of the aqueous solution of HCl is 0.04-0.1 mol/L;

step 3, immersing the cellulose paper with palladium adhered on the surface prepared in the step 2 into NiCl₂、Na₃C₆H₆O₇、NH₄Cl and NaH₂PO₂In the formed plating solution, the temperature is kept at 70-90 ℃, the pH value of the plating solution is adjusted by ammonia water solution to be kept at 7-8, after 20-40min of reaction, the plating solution is taken out, cleaned and dried, and the nickel-phosphorus nano material taking flexible paper as a substrate is obtained, wherein NiCl is used as the substrate₂、Na₃C₆H₆O₇、NH₄Cl and NaH₂PO₂The mass ratio of (3-5) to (5-7) to (3-6) to (0.5-1.8).

In step 1, SnCl₂The concentration of the aqueous solution is 0.05-0.1mol/L, the concentration of the aqueous solution of HCl is 0.1-0.25mol/L, and the soaking time is 20-30 min.

In step 2, PdCl₂The concentration of the aqueous solution is 0.8-1.2mmol/L, the concentration of the aqueous solution of HCl is 0.04-0.1mol/L, the soaking time is 25-30min, the drying temperature is 50-60 ℃, and the drying time is 0.5-2 h.

In step 3, NiCl₂、Na₃C₆H₆O₇、NH₄Cl and NaH₂PO₂The mass ratio of (4-5) to (6-7) to (4-6) to (0.6-1.2), the drying temperature is 55-65 ℃, and the drying time is 0.5-2 h.

The invention has the beneficial effects that: the nickel-phosphorus paper is prepared by adopting simple solution soaking and chemical plating methods, the experimental steps are simple, and the experiment is simpleThe method has mild conditions, can be used for large-scale industrial production, and has potential of practical application; the nickel-phosphorus nano material with different shapes, such as nanoflower, nanosheet, nanowire microsphere and microsphere, is obtained by adjusting the pH value and concentration of the chemical plating solution, and the nickel-phosphorus nano material endows the cellulose paper with conductivity, has potential sensitivity to urea due to high catalytic activity and provides possibility for manufacturing a non-enzymatic urea sensor; the nickel-phosphorus nano material is loaded on the cellulose paper, has higher electro-catalysis performance to urea, compares the electrochemical behaviors of four paper electrodes of the nickel-phosphorus nano material with different shapes and taking flexible paper as a substrate, and the result shows that the paper electrode of the nickel-phosphorus nano material with the flexible paper as the substrate has the best electrochemical performance in a low concentration range (0-1mm), and the sensitivity is 682-^-1cm^-2The electrochemical performance is best in a low concentration range (0-1mm), and the sensitivity is 1135-^-1cm^-2In the high concentration range (1-11mm), the lowest detection limit is 11-15 μm, the shortest response time is 2-4s, which may be attributed to the highest surface area of the nickel-phosphorus nanoflower structure, 97% stability can be maintained in indoor environment after 35 days of storage, and furthermore, the electrocatalytic activity of four different morphologies of flexible paper-based nickel-phosphorus nanomaterial paper electrodes is ranked as follows: nanometer flower>Nano-sheet>Nanowire microspheres>And (3) microspheres.

Drawings

FIG. 1 is a scanning electron microscope image of nano-flower nickel-phosphorus paper with different shapes prepared by the invention;

FIG. 2 is a scanning electron microscope image of nano-wire microspheres with different shapes prepared by the invention;

FIG. 3 is a scanning electron microscope image of nanospheres of different shapes prepared according to the present invention;

FIG. 4 is a scanning electron microscope image of nanosheets of different morphologies prepared according to the present invention;

FIG. 5 is an X-ray diffraction pattern of nickel-phosphorus nanoflowers, nanosheets, nanowire microspheres and microspheres grown on the cellulose paper prepared by the present invention;

FIG. 6 is a graph showing the relationship between the oxidation current of the nickel-phosphorus nanoflower, nanosheet, nanowire microsphere and microsphere grown on the cellulose paper prepared by the method of the present invention and the pH of the NaOH solution;

FIG. 7 is a current response diagram of four different forms of nickel-phosphorus paper electrodes prepared by the present invention to continuous injection of 0.1M NaOH into urea.

Detailed Description

The technical solution of the present invention is further illustrated by the following specific examples.

Example 1

(1) Cutting cellulose paper (2X 6 cm)²) First immersed in 0.05m SnCl₂And 0.15m HCl solution for 30 minutes, then the paper is taken out and rinsed gently with deionized water and acetone. Finally drying in air to remove Sn²⁺Adhered to its surface, the structure of which is shown in figure 1.

(2) Sn is added²⁺The activated paper was soaked in 0.6mM pdcl2 and 0.03M HCl solution for 30 minutes and then rinsed thoroughly with deionized water and acetone. Finally drying in a hot oven at 60 ℃ to attach palladium on the surface, and the structure is shown in figure 2.

(3) And adhering the nickel-phosphorus nano material on the surface of the paper to obtain the conductive nickel-phosphorus paper. The Pd-activated paper was dipped in a solution of 3.33g of NiCl₂、5.88g Na₃C₆H₆O₇、3.2g NH₄Cl、0.88g NaH₂PO₂In an electroless bath of composition. Keeping the temperature at 80 ℃, adjusting the pH value of the plating solution by 27 wt% ammonia water solution to keep the pH value at 7-8, reacting for 30min, and in the process, taking palladium as a catalyst and adding Ni²⁺Is converted into nickel. After the chemical bath, the resulting paper was thoroughly washed clean with deionized water and acetone and then dried in a hot oven at 60 ℃ to obtain conductive nickel-phosphorus paper having a structure shown in fig. 3.

Example 2

(1) Cutting cellulose paper (2X 6 cm)²) First immersed in 0.08m SnCl₂And 0.20m HCl solution for 25 minutes, then the paper is taken out and rinsed gently with deionized water and acetone. Finally drying in air to remove Sn²⁺Adhering to its surface.

(2) Sn is added²⁺Active paper soakingIn 0.4mM pdcl2 and 0.05M HCl solution for 20 minutes, then rinsed well with deionized water and acetone. And finally drying in a hot oven at 60 ℃ to ensure that palladium is attached to the surface of the film.

(3) And adhering the nickel-phosphorus nano material on the surface of the paper to obtain the conductive nickel-phosphorus paper. The Pd-activated paper was dipped in a solution of 4.33g of NiCl₂、6g Na₃C₆H₆O₇、4g NH₄Cl、0.88g NaH₂PO₂In an electroless bath of composition. Keeping the temperature at 80 ℃, adjusting the pH value of the plating solution by using 30 wt% ammonia water solution to keep the pH value at 7-8, reacting for 20min, and in the process, taking palladium as a catalyst and adding Ni²⁺Is converted into nickel. After the chemical bath, the obtained paper was thoroughly washed clean with deionized water and acetone, and then dried in a hot oven at 70 ℃ to obtain conductive nickel-phosphorus paper.

Example 3:

(1) cutting cellulose paper (2X 6 cm)²) First immersed in 0.1m SnCl₂And 0.3m HCl solution for 15 minutes, then the paper is taken out and rinsed gently with deionized water and acetone. Finally drying in air to remove Sn²⁺Adhering to its surface.

(2) Sn is added²⁺The activated paper was soaked in 0.3mM pdcl2 and 0.15M HCl solution for 20 minutes and then rinsed thoroughly with deionized water and acetone. And finally drying in a hot oven at 60 ℃ to ensure that palladium is attached to the surface of the film.

(3) And adhering the nickel-phosphorus nano material on the surface of the paper to obtain the conductive nickel-phosphorus paper. The Pd-activated paper was dipped in a solution of 5.55g NiCl₂、7.68g Na₃C₆H₆O₇、4.6g NH₄Cl、1.66g NaH₂PO₂In an electroless bath of composition. Keeping the temperature at 80 ℃, adjusting the pH value of the plating solution by using 16 wt% ammonia water solution to keep the pH value at 7-8, reacting for 40min, and in the process, taking palladium as a catalyst and adding Ni²⁺Is converted into nickel. After the chemical bath, the obtained paper is thoroughly washed clean with deionized water and acetone and then dried in a hot oven at 60 ℃ to obtain the conductive nickel-phosphorus paper.

The performance test of the nickel-phosphorus nano material taking the flexible paper as the substrate is carried out as follows:

to prepare an area of 2X 1cm²The nickel-phosphorus paper is used as a working electrode, the platinum wire is used as a counter electrode, Ag/AgCl (in saturated KCl solution) is used as a reference electrode, a conventional three-electrode electrochemical cell is constructed, and an electrochemical test is carried out. Amperometry, Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV) were performed at room temperature of 20-25 deg.C.

And (3) adopting a polytetrafluoroethylene adhesive tape to keep the immersion area of the nickel-phosphorus nano material taking the flexible paper as the substrate to be 1cm multiplied by 1 cm. These measurements were made in 0.10 mNaOH. In addition, all ampere tests were accompanied by a slight stirring (100 rpm).

As shown in fig. 6, the anodic peak current density increased with increasing pH of the solution, but the anodic peak current density increased only weakly when the pH12 of the solution was low. When the pH of the solution was increased to 13, the pH of the solution increased significantly.

The detection performance of Ni-P paper with different shapes on urea is measured by adopting a chronoamperometry (ca), and 0.7V is set as the potential in ca measurement. As shown in FIG. 7, there are four current-time (I-t) curves, the current response increases sharply with successive urea injections, and good catalytic response is shown in the range of 0.05-11 mm.

The invention has been described in an illustrative manner, and it is to be understood that any simple variations, modifications or other equivalent changes which can be made by one skilled in the art without departing from the spirit of the invention fall within the scope of the invention.