CN108807004A - A kind of NiO/H-TiO2The preparation method of nanometer tube combination electrode - Google Patents

Abstract

The invention discloses one kind being based on TiO₂Method prepared by nanotube electrochemical modification and its combination electrode, specially anodizing, electrochemical reducing and differential pulse method, which are combined, prepares TiO₂Nano-tube array, then be modified, deposition of electrode material is to prepare high-performance combination electrode.Its technical solution is：First using pure titanium as substrate in two electrode systems, structurally ordered, morphology controllable, pipe range and the controllable Nano tube array of titanium dioxide of thickness are prepared using an anodizing；Secondly in two electrode systems, reversely powering up pressure processing carries out electrochemistry hydrogen loading；Finally by the H-TiO of preparation₂Nanotube carries out electrochemical deposition nickel oxide nanoparticle in three-electrode system by differential pulse voltammetry.NiO/H-TiO prepared by this method₂Combination electrode nano particle is evenly distributed, and size tunable, electric conductivity is strong, has higher specific capacitance and energy density, can more preferably be applied to electrochemical energy storage field and area of solar cell.

Description

A kind of preparation method of NiO/H-TiO2 nanotube composite electrode

technical field

The invention belongs to the technical field of energy storage, and specifically relates to a method for preparing a NiO/H- _TiO2 nanotube composite electrode. The method adopts an anodic oxidation method, an electrochemical reduction method and a differential pulse method to prepare NiO/H-TiO2 ₂ nanotube composite electrode, the NiO/H-TiO ₂ nanotube composite electrode prepared by this method has good conductivity and ultra-high energy density, which provides a new idea for improving the performance of energy storage devices.

Background technique

In recent years, due to the advantages of high power density, fast charge and discharge speed, long cycle life, strong cycle stability, clean and pollution-free, supercapacitors have attracted widespread attention in the fields of electronic products, solar cells, distributed energy storage and new energy vehicles. . According to the reaction mechanism, supercapacitors can be divided into electric double layer capacitors and pseudocapacitors. Electric double layer capacitors have the advantages of fast charge and discharge speed and long life, but the low energy density and poor conductivity of electric double layer capacitors limit their application fields. The redox reaction of the pseudocapacitive capacitor occurs on the surface of the active electrode, which has high specific capacitance and high energy density, and its specific capacitance is 4-10 times that of the electric double layer capacitance. So far, hydrated ruthenium oxide is the most promising electrode material among various pseudocapacitive electrode materials, however, the high cost of ruthenium oxide limits its application in supercapacitors.

Because TiO ₂ nanotubes have low-cost preparation process, large specific surface area, and good electron transport path, they have potential application value in the field of supercapacitors. However, due to the semiconducting properties of pristine _TiO2 nanotubes, their electrical conductivity is very poor, and they exhibit low electric double layer capacitance, so they cannot be directly used as electrode materials. A large number of experiments have proved that doping TiO ₂ nanotubes is an effective means of modification. Currently, the most economical, simple and effective method for doping _TiO2 nanotubes is the electrochemical reduction method. However, pure self-doping of TiO ₂ nanotubes by electrochemical reduction method can improve its capacitance performance to a certain extent, but it is far from meeting the application requirements. Therefore, _TiO2 nanotubes with higher conductivity are more suitable as the framework structure of supercapacitors to deposit pseudocapacitive electrode materials with better capacitance performance, thereby greatly improving the performance of capacitors and better applied in the field of electrochemical energy storage and solar energy. battery field.

Contents of the invention

Aiming at the problems in the above-mentioned prior art, the present invention provides a method for electrochemically doping _TiO2 nanotubes as a framework material to deposit NiO, a pseudocapacitive electrode material, to form a composite electrode. The _TiO2 nanotube composite electrode prepared by the method has high specific volume, high electrical conductivity and high energy density, and can prepare a dielectric capacitor with an energy density level of a supercapacitor.

In order to achieve the above object, the technical scheme adopted in the present invention is: a kind of NiO/H- _TiO2 nanotube composite electrode preparation method, adopts multiple electrochemical processes to _TiO2 electrode is modified, and its steps are as follows:

1) In the two-electrode system, TiO ₂ nanotubes with controllable three-dimensional morphology were prepared, cleaned, dried and calcined; 2) In the two-electrode system, the TiO ₂ nanotube electrodes were treated with reverse voltage to introduce hydrogen Miscellaneous, made H-TiO ₂ nanotubes;

3) Electrochemically depositing nickel hydroxide on the prepared H-TiO ₂ nanotube electrode in a three-electrode system, and calcining to obtain a NiO/H-TiO ₂ nanotube electrode.

A kind of above-mentioned NiO/H-TiO ₂ preparation method of nanotube composite electrode, when preparing the TiO ₂ nanotube with controllable three-dimensional appearance, use titanium sheet as anode, graphite as counter electrode, before anodic oxidation, titanium sheet is respectively in acetone , ethanol and deionized water for ultrasonic cleaning for 10 minutes, and then perform anodic oxidation in the electrolyte solution of ethylene glycol with a mass ratio of 0.25% NH ₄ F and 2% deionized water, and anodize the titanium sheet after anodic oxidation Wash and dry.

The preparation method of the above-mentioned NiO/H- _TiO2 nanotube composite electrode, the length range of the prepared three-dimensional morphology controllable _TiO2 nanotube is 12-15 μm, the diameter range is 107-128nm, and the outer diameter range is 170-500 nm.

In the above method for preparing a NiO/H-TiO ₂ nanotube composite electrode, the calcination temperature of the TiO ₂ nanotube is 400-600°C.

A kind of above-mentioned NiO/H _{- TiO2} nanotube composite electrode preparation method, with _TiO2 nanotube array as cathode, graphite as anode, in 0.5M _Na2SO4 electrolytic solution carries out electrochemical hydrogen doping treatment, two electrodes The distance between them is 2-3cm, the applied voltage is 5V and the reaction treatment time is 30s.

The preparation method of above-mentioned a kind of NiO/H-TiO ₂ nanotube composite electrode, with H-TiO ₂ nanotube electrode as working electrode, Hg/Hg ₂ Cl ₂ electrode is reference electrode, platinum grid electrode is counter electrode, in Nickel was electrochemically deposited by differential pulse voltammetry in 0.04 M NiCl ₂ electrolyte. After the electrochemical deposition, cyclic voltammetry was used in 1M KOH solution at -1 V Scan 10 pulse cycles at 100 mV/s in the voltage range of 1V to form a complete metal hydroxide, which becomes nickel oxide after calcination.

Compared with the prior art, the present invention has the advantage of undergoing two electrochemical modifications: for the first time, in a two-electrode system, _TiO nanotubes are treated with reverse voltage and hydrogen doping, and the method is simple and easy; Electrochemical deposition of nickel hydroxide is carried out in the electrochemical workstation of the three-electrode system, and the constant current charge-discharge curve and cyclic voltammetry curve can be easily obtained during the process. The method perfectly self-doped the TiO ₂ nanotube, enhanced the electrical conductivity, significantly increased the specific capacitance, and significantly improved the electrochemical performance, thereby having a better application prospect.

Description of drawings

Fig. 1 is the morphology and structure of the untreated _TiO nanotube prepared in Example 1.

Figure 2 is the morphology and structure of the electrochemically modified NiO/H-TiO ₂ nanotubes prepared in Example 3.

Fig. 3 is the cyclic voltammetry characteristic curve of the untreated TiO ₂ nanotube electrode prepared in Example 1.

Fig. 4 is the cyclic voltammetry characteristic curve of the H-doped TiO ₂ nanotube electrode prepared in Example 2.

Fig. 5 is the cyclic voltammetry characteristic curve of the electrochemically modified NiO/H-TiO ₂ nanotube electrode prepared in Example 3.

Fig. 6 is the galvanostatic charge-discharge characteristic curve of the untreated TiO ₂ nanotube electrode prepared in Example 1.

Fig. 7 is the galvanostatic charge and discharge characteristic curve of the H-doped TiO ₂ nanotube electrode prepared in Example 2.

Fig. 8 is the constant current charge and discharge characteristic curve of the electrochemically modified NiO/H-TiO ₂ nanotube electrode prepared in Example 3.

Detailed ways

Example 1

In the two-electrode system, the three-dimensional morphology-controllable TiO ₂ nanotube electrode was prepared by the constant pressure method: the commercially pure titanium sheet was ultrasonically cleaned in acetone, absolute ethanol and deionized water for 10 min, and dried. At room temperature, with the titanium sheet as the anode and the graphite as the counter electrode, the distance between the titanium sheet and the graphite electrode is 2-3 cm, in the ethylene glycol solution with a mass fraction of 0.25% NH ₄ F and 2% deionized water Anodizing is performed by applying a constant voltage. After the anodic oxidation is completed, the generated TiO ₂ nanotube electrode is ultrasonically cleaned for 30 s in absolute ethanol to remove the residual electrolyte on the surface of the nanotube. The obtained _TiO2 nanotubes have a length ranging from 12-15 μm, a tube diameter ranging from 107-128 nm, and an outer diameter ranging from 170-500 μm. The amorphous _TiO2 nanotube electrode was calcined in a tube furnace at 450 °C.

Example 2

The preparation and calcination temperature of the three-dimensional shape-controllable _TiO2 nanotube electrode are the same as in Example 1. The crystalline _TiO2 nanotube array is used as the cathode and the graphite is used as the anode for electrochemical hydrogen doping treatment in _0.5MNa2SO4 electrolyte _. The distance between the two electrodes is 2-3cm, the applied voltage is 5V and the reaction treatment time is 30s.

Example 3

The preparation and calcination temperature of the three-dimensional shape-controllable _TiO2 nanotube electrode are the same as in Example 1, the preparation of the H-doped _TiO2 nanotube electrode is the same as in Example 2, and the H- _TiO2 nanotube electrode is used as the working electrode, Hg/Hg The ₂ Cl ₂ electrode was used as a reference electrode, and the platinum mesh electrode was used as a counter electrode. Electrochemical deposition of nickel hydroxide was carried out by differential pulse voltammetry in 0.04MNiCl ₂ electrolyte. After the electrochemical deposition was completed, in 1M KOH solution Using cyclic voltammetry to scan 10 pulse periods at 100 mV/s in the voltage range of -1 V–1 V to form a complete metal hydroxide, which was calcined at 300 °C in a tube furnace to become NiO/H-TiO ₂ nanotube composite electrodes.

Claims (6)

1. a kind of NiO/H-TiO ₂ the preparation method of nanotube composite electrode, it is characterized in that adopt multiple electrochemical processes to TiO ₂ electrode is modified, and its steps are as follows: 1) In a two-electrode system, three-dimensional shape-controllable _TiO nanotubes were prepared, washed, dried and calcined; 2) In the two-electrode system, the _TiO2 nanotube electrode is treated with reverse voltage to introduce hydrogen doping, and the H- _TiO2 nanotube electrode is obtained; 3) In the three-electrode system, nickel hydroxide is electrochemically deposited on the H-TiO ₂ nanotube electrode prepared in 2), and then calcined to obtain a NiO/H-TiO ₂ nanotube electrode. 2. a kind of NiO/H- _TiO as claimed in claim 1 The preparation method of nanotube composite electrode is characterized in that when preparing the _TiO nanotube with three-dimensional appearance controllable, with titanium plate as anode, graphite as counter electrode Before anodizing, the titanium sheet was ultrasonically cleaned in acetone, ethanol, and deionized water for 10 minutes, and then anodized in an electrolyte solution of ethylene glycol with a mass ratio of 0.25% NH ₄ F and 2% deionized water. The anodized titanium sheet is cleaned and dried. 3. a kind of NiO/H-TiO as claimed in claim ₂ The preparation method of the nanotube composite electrode is characterized in that the _TiO of the three-dimensional morphology controllable of preparation The length scope of the nanotube is 12-15 μ m, The tube diameter ranges from 107-128nm, and the outer diameter ranges from 170-500 nm. 4. The preparation method of a NiO/H-TiO ₂ nanotube composite electrode as claimed in claim 1 or 2, characterized in that the calcination temperature of the TiO ₂ nanotube is 400-600°C. 5. A method for preparing a NiO/H- _TiO2 nanotube composite electrode as claimed in claim 1 or ₂ , characterized in that the _TiO2 nanotube array is used as the cathode, and the graphite is used as the anode, in 0.5M _Na2SO4 Electrochemical hydrogen doping treatment is carried out in the electrolyte, the distance between the two electrodes is 2-3cm, the applied voltage is 5V and the reaction treatment time is 30s. 6. a kind of NiO/H-TiO as claimed in claim ₂ The preparation method of nanotube composite electrode is characterized in that with H-TiO ₂ nanotube electrode is working electrode, Hg/Hg ₂ Cl ₂ electrode is The reference electrode, the platinum grid electrode as the counter electrode, nickel was electrochemically deposited by differential pulse voltammetry in 0.04 MNiCl ₂ electrolyte, after the electrochemical deposition was completed, cyclic voltammetry was used in 1M KOH solution at -1 V Scanning 10 pulse periods at 100 mV/s in the voltage range of 1 V forms a complete metal hydroxide, which becomes nickel oxide after calcination.