A kind of method that in the engineering plastics substrate, prepares lead dioxide electrode plate
Technical field
The invention belongs to electrochemistry skill technical field, particularly a kind of method that in the engineering plastics substrate, prepares lead dioxide electrode plate.The lead dioxide electrode plate suitable application area that method of the present invention is prepared is extensive, and like the electrowinning zinc in the hydrometallurgy, electro deposited copper also can be used for fields such as electrochemistry wastewater treatment and lead acid cell.
Background technology
Lead dioxide electrode has higher oxygen evolution potential as insoluble anode commonly used in the industry, and cost is low; Good conductivity; Advantages such as the preparation method is simple and be widely used in electrochemical synthesis, electrochemical sensor, electrochemistry wastewater treatment; The ozone preparation, fields such as hydrometallurgy and battery industry.
The preparation of lead dioxide electrode, selecting titanium, graphite, plastics, pottery etc. usually for use is organism material, handles through surface coarsening, is coated with zinc-plated antimony zone of oxidation, electroplates primary processes such as titanium dioxide lead layer, makes lead dioxide electrode.But the lead dioxide electrode of preparing like this is as insoluble anode; Variety of issue in use often appears; As: (1) plumbic oxide settled layer combines undertighten or settled layer inhomogeneous with substrate: (2) titanium dioxide lead layer internal stress is big, peels off easily after long-time the use, influences its life-span.
Summary of the invention
The preparation method who the purpose of this invention is to provide a kind of lead dioxide electrode plate.
A kind of method that in the engineering plastics substrate, prepares lead dioxide electrode plate, this method may further comprise the steps:
(1) prepare anode: the engineering plastics substrate carries out surface treatment makes its surface form the plumbic oxide conductive layer of fine and close conduction; The purpose of preparation plumbic oxide conductive layer is to form conductive layer at frosting, so that final galvanized realization;
(2) adopt pulse current method to electroplate: the engineering plastics substrate that forms the plumbic oxide conductive layer of fine and close conduction with the surface is that anode is put into electroplate liquid, and negative electrode adopts graphite rod or stainless steel plate, current density 50-400A/m
2, burst length 1s-5s, pitch time 0.1s-2s, temperature 20-60 ℃, under the pneumatic blending condition, electroplate, on anode, form the plumbic oxide electrolytic coating, obtain lead dioxide electrode plate.
In the aforesaid method, the preferred 80-200A/m of current density
2, preferred 1s-2s of burst length, pitch time preferred 0.5s-2s.
Electroplating bath components is lead nitrate 200-250g/L, nitric acid 20-30g/L.
Preferred 1-15h of electrodeposition time.
Plumbic oxide electrolytic coating thickness is 0.5-4mm, preferred 2-4mm.
In the aforesaid method; Said engineering plastics substrate surface treatment step is following: the engineering plastics substrate carries out carrying out electroless plating after oil removing, chemical etching processing, the sensitizing and activating processing; After the electroless plating processing, the engineering plastics substrate surface forms the plumbic oxide conductive layer of fine and close conduction.
Wherein, said engineering plastics substrate carries out oil removing, the chemical etching treatment step is following: at first the engineering plastics substrate is immersed in the alkaline solution, remove surface and oil contaminant, pull the back out with washing; Dry up, the engineering plastics substrate is immersed in the chemical erosion liquid, form many small cavities at frosting; Improve interface binding power, the etchant compound method is chromium trioxide 300-400g/L; Vitriol oil 400-450g/L, the etchant temperature is 60-70 ℃, erosion time 10-15 minute; Pull substrate out after corrode finishing, the sodium sulfite solution of putting into massfraction and be 2%-5% soaked 5 minutes, and residual sulfuric acid and chromium neutralize;
Wherein, said sensitization and activation treatment step are following: substrate is put into sensitized solution at room temperature soaked 2 minutes, took out parked 1 minute; Putting into activated solution at room temperature soaked 4 minutes; After continuous sensitizing and activating 3-7 time, wash, dry, wherein; Sensitized solution consists of: tin protochloride 1-5g/L, concentrated hydrochloric acid 3-6ml/L; Activated solution consists of: Silver Nitrate 1-5g/L;
Wherein, said electroless plating step is following: substrate is immersed in the chemical plating fluid, and temperature is controlled at 35-45 ℃, and soak time is 2 hours, and chemical plating fluid is mixed by A liquid and B liquid equal-volume, and wherein, A liquid consists of: lead nitrate 20-30g/L, ammonium acetate 20-50g/L; B liquid consists of: ammonium persulphate 40-50g/L, ammoniacal liquor regulate the pH value to 9.0-10.0.
The present invention adopts pulse current method to electroplate, and its beneficial effect is following:
(1) the lead dioxide electrode plate good conductivity of the inventive method preparation, solidity to corrosion is good.
(2) the smooth densification of the galvanized plumbic oxide conductive layer of pulse current method method of the present invention, bonding force is good, difficult drop-off.
(3) lead dioxide electrode plate working method of the present invention is simple, and cost is low, is easy to apply.
Description of drawings
The PbO that Fig. 1 tradition constant current anodizing process is prepared
2Surface topography;
The PbO that Fig. 2 pulse current method is prepared
2Surface topography.
Embodiment
Below in conjunction with accompanying drawing the present invention is described further:
Embodiment 1
Sodium hydroxide oil removing with vinyon substrate immersion 10%.Then polyethylene board is immersed in the chemical erosion liquid, the etchant temperature is 65 ℃, time 15min.The etchant composition is chromium trioxide 350g/L, vitriol oil 420g/L.Pull substrate out after corrode finishing, put into 3% sodium sulfite solution and soak 5min, residual sulfuric acid and chromium neutralize.
Sensitization and activation treatment, sensitized solution consists of: tin protochloride 3g/L, concentrated hydrochloric acid 4ml/L.Activated solution is: Silver Nitrate 3g/L.Substrate is put into sensitized solution at room temperature soaked 2 minutes, took out parked 1 minute, put into activated solution and at room temperature soaked 4 minutes.After the continuous sensitizing and activating 6 times, wash, dry.
Chemistry preparation chemical plating fluid, it consists of A liquid (lead nitrate 27g/L, ammonium acetate 43g/L), B liquid (ammonium persulphate 42g/L, it is 9.0-10.0 that ammoniacal liquor is regulated PH), equal-volume mixing A liquid and B liquid immerse substrate, and temperature is controlled at 40 ℃, and soak time is 2 hours.
Handle through electroless plating, substrate surface forms the plumbic oxide electrically conductive layer of fine and close conduction, can carry out electrochemical deposition.The engineering plastics substrate that forms the plumbic oxide electrically conductive layer of fine and close conduction with the surface is that anode is put into electroplate liquid, and electroplating bath components is lead nitrate 250g/L, nitric acid 30g/L, and negative electrode adopts graphite rod.Current density 80A/m
2, burst length 1s, pitch time 0.2s, 50 ℃ of temperature, pneumatic blending, 8 hours electrodeposition time, form the plumbic oxide electrolytic coating of thickness 2mm, obtain lead dioxide electrode plate.
The lead dioxide electrode plate PbO of present embodiment preparation
2Surface topography is as shown in Figure 2.The PbO for preparing with traditional constant current anodizing process
2Surface topography (as shown in Figure 1) is compared, the more smooth densification of the galvanized plumbic oxide conductive layer of pulse current method, and bonding force is good, difficult drop-off.
Embodiment 2
Except in temperature be electroplate under 20 ℃, all the other are identical with embodiment 4.
Embodiment 3
Except in temperature be electroplate under 60 ℃, all the other are identical with embodiment 4.
Embodiment 4
Except electroplating bath components is lead nitrate 250g/L, nitric acid 30g/L, electrodeposition time 9h, the plumbic oxide electrolytic coating of formation total thickness 4mm obtains outside the lead dioxide electrode plate, and all the other are identical with embodiment 1.
Embodiment 5
Current density 400A/m during except plating
2, burst length 1s, outside pitch time, 1s carried out, all the other were identical with embodiment 1.
Embodiment 6
Current density 50A/m during except plating
2, burst length 2s, outside pitch time, 0.5s carried out, all the other were identical with embodiment 1.
Embodiment 7
Current density 300A/m during except plating
2, burst length 3s, outside pitch time, 1.5s carried out, all the other were identical with embodiment 1.