阅读说明：本技术 一种光催化选择性金属溶解剂及溶解方法 (Photocatalytic selective metal dissolving agent and dissolving method ) 是由 卞振锋 陈瑶 徐梦娇 闻洁雅 万瑜 李和兴 于 2019-09-26 设计创作，主要内容包括：本发明涉及一种光催化选择性金属溶解剂及溶解方法,该溶解剂为含光催化剂的氰类化合物溶液,所述的溶液中含水量为0-50wt％,所述的溶液中光催化剂的含量为0.01-50mg/mL。光催化选择性金属溶解方法,该方法为：将金属材料分散到光催化选择性金属溶解剂中,光照射一定时间即可对金属材料中各个金属进行选择性溶解。与现有技术相比,本发明突破了对贵金属选择性溶解过程的现有认识,对金属在环境中的演变以及金属开采或金属分离提纯处理有指导意义。(The invention relates to a photocatalytic selective metal dissolving agent and a dissolving method, wherein the dissolving agent is a cyanogen compound solution containing a photocatalyst, the water content of the solution is 0-50 wt%, and the content of the photocatalyst in the solution is 0.01-50 mg/mL. A photocatalytic selective metal dissolution method comprises the following steps: the metal material is dispersed into the photocatalytic selective metal dissolving agent, and each metal in the metal material can be selectively dissolved by irradiating light for a certain time. Compared with the prior art, the invention breaks through the prior knowledge of the selective dissolution process of the noble metal and has guiding significance for the evolution of the metal in the environment and the metal mining or the metal separation and purification treatment.)

1. The photocatalytic selective metal dissolving agent is characterized in that the dissolving agent is a cyanogen compound solution containing a photocatalyst, the water content of the solution is 0-50 wt%, and the content of the photocatalyst in the solution is 0.01-50 mg/mL.

2. The selective metal dissolvent for photocatalysis according to claim 1, wherein the photocatalyst comprises inorganic photocatalytic material, organic photocatalytic material, semiconductor photocatalytic material and photocatalytic material modified, surface modified and compounded with each other.

3. A photo-catalytic selective metal dissolvent according to claim 2, wherein the inorganic photo-catalytic material comprises one or more of titanium dioxide, cadmium sulfide, bismuth vanadate, tungsten oxide;

the organic photocatalytic material comprises one or more of carbon nitride, porphyrin, biomimetic enzyme or porphyrin supermolecule organic polymer and metal organic compound;

the semiconductor photocatalytic material and the photocatalytic material which is modified, surface-modified and mutually compounded comprise a titanium dioxide material containing oxygen vacancies, a hydroxyl-modified titanium dioxide material, a two-dimensional structure titanium dioxide material, a nitrogen-doped titanium dioxide material, porphyrin-sensitized titanium dioxide and a porphyrin self-assembly material, wherein the porphyrin comprises protoporphyrin, ferriporphyrin, magnesium porphyrin or zinc porphyrin, titanium dioxide composite amino modified metal organic compound material, molybdenum disulfide loaded titanium dioxide, cadmium sulfide composite material, cadmium sulfide quantum dot material, in-situ tungsten sulfide oxide composite material, phosphorus doped indium oxide material, nitrogen-deficient carbon nitride composite material and carbon material modified carbon nitride material, the carbon material comprises carbon dots, graphene or carbon nano tubes, a layered bismuth oxybromide material, an oxygen-defect-containing bismuth oxybromide material, a biomimetic catalytic enzyme material and an organic photosystem and inorganic catalyst composite material.

4. The photo-catalytic selective metal dissolvent according to claim 1, wherein the cyanide compound comprises one or more of acrylonitrile, acetonitrile, phenylacetonitrile, cyanoacetic acid, malononitrile, cyanobenzyl, or melamine.

5. A method for photocatalytic selective metal dissolution using the photocatalytic selective metal dissolution agent according to any one of claims 1 to 4, characterized by: the metal material is dispersed into the photocatalytic selective metal dissolving agent, and each metal in the metal material can be selectively dissolved by irradiating light for a certain time.

6. The method of claim 5, wherein the mass ratio of the metal material to the photocatalyst is 1 (0.01-1).

7. A photocatalytic selective metal dissolution method as set forth in claim 5, wherein the metallic material includes one or more of copper, silver and gold.

8. The method of claim 7, wherein the metal material further comprises one or more of iron, manganese, chromium, zinc, tin, lead, aluminum, titanium, ruthenium, rhodium, iridium, and palladium.

9. The method as claimed in claim 5, wherein the light irradiation wavelength is 150-1500nm and the light irradiation time is 2-4 h.

10. The method of claim 5, wherein an oxygen-containing gas or a chemical substance capable of generating oxygen is added to the photocatalytic selective metal dissolution agent during the dissolution process, so that the oxygen content of the photocatalytic selective metal dissolution agent is 5 to 100%; the chemical substance capable of generating oxygen comprises one or more of ozone, hydrogen peroxide or sodium peroxide.

Technical Field

The invention relates to the field of photocatalysis application, in particular to a photocatalysis selective metal dissolving agent and a dissolving method.

Background

With the rapid development of science and technology, the utilization rate of metal is higher and higher, and most of metals can play a greater role when used in combination. However, the metal content is limited and is very important for the recovery and reuse of the metal. Among them, selective dissolution of metals is one of the most important processes in recovery, in the existing method, metals are mostly dissolved and recovered by strong acid (aqua regia), the metal ion solution obtained by the method has no selectivity, and the whole process is harmful to the environment, the recovery cost is very high, and the pollution is serious.

Patent CN108728645A discloses a process for the dissolution and activation of iron alloy acid containing precious metals, which utilizes oxide to separate the generated reactant residue from molten iron, and utilizes aqua regia to dissolve precious metals. The temperature of molten iron formed by melting ferroalloy is up to 1200-1500 ℃, the conditions are very harsh, and the aqua regia with extremely strong corrosivity is used in the process. Patent CN107502745A discloses a method for selectively recycling gold and silver noble metal ions, which uses poly-dopamine on the lower surface of a carbon tube film to reduce gold and silver ions in waste liquid into gold and silver nano-particles, and the gold and silver nano-particles are adsorbed on the lower surface of the carbon tube film to form a carbon tube, gold or silver nano-particle composite film material. The carbon tube composite film has complicated preparation steps, and the recycled noble metal material can only form a composite film material.

Therefore, it is very urgent to develop a green and environmentally friendly method for selectively dissolving metals effectively. The photocatalysis has the advantages of mild reaction conditions and capability of directly converting solar energy into chemical energy, is paid attention by scientific researchers, and shows great application prospects in the fields of energy and environmental protection. The photocatalytic metal dissolution brings a very important opportunity for environmental protection and energy utilization, and contributes to the transition to low-carbon and resource-saving green economy.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a photocatalytic selective metal dissolving agent and a dissolving method under mild and environment-friendly conditions.

The purpose of the invention can be realized by the following technical scheme:

a photocatalytic selective metal dissolving agent is a cyanogen compound solution containing a photocatalyst, the water content of the solution is 0-50 wt%, and the content of the photocatalyst in the solution is 0.01-50 mg/mL.

Further, the photocatalyst comprises inorganic photocatalytic materials, organic photocatalytic materials, semiconductor photocatalytic materials and photocatalytic materials which are modified, surface-modified and mutually compounded.

Further, the inorganic photocatalytic material comprises one or more of titanium dioxide, cadmium sulfide, bismuth vanadate and tungsten oxide;

the organic photocatalytic material comprises one or more of carbon nitride, porphyrin, biomimetic enzyme or porphyrin supermolecule organic polymer and metal organic compound;

the semiconductor photocatalytic material and the photocatalytic material which is modified, surface-modified and mutually compounded comprise a titanium dioxide material containing oxygen vacancies, a hydroxyl-modified titanium dioxide material, a two-dimensional structure titanium dioxide material, a nitrogen-doped titanium dioxide material, porphyrin-sensitized titanium dioxide and a porphyrin self-assembly material, wherein the porphyrin comprises protoporphyrin, ferriporphyrin, magnesium porphyrin or zinc porphyrin, titanium dioxide composite amino modified metal organic compound material, molybdenum disulfide loaded titanium dioxide, cadmium sulfide composite material, cadmium sulfide quantum dot material, in-situ tungsten sulfide oxide composite material, phosphorus doped indium oxide material, nitrogen-deficient carbon nitride composite material and carbon material modified carbon nitride material, the carbon material comprises carbon dots, graphene or carbon nano tubes, a layered bismuth oxybromide material, an oxygen-defect-containing bismuth oxybromide material, a biomimetic catalytic enzyme material and an organic photosystem and inorganic catalyst composite material.

Further, the cyanogen compound comprises one or more of acrylonitrile, acetonitrile, phenylacetonitrile, cyanoacetic acid, malononitrile, cyanobenzyl or melamine.

A method for carrying out photocatalytic selective metal dissolution by adopting the photocatalytic selective metal dissolution agent comprises the following steps: the metal material is dispersed into the photocatalytic selective metal dissolving agent, and each metal in the metal material can be selectively dissolved by irradiating light for a certain time.

Furthermore, the mass ratio of the metal material to the photocatalyst is 1 (0.01-1).

Further, the metal material includes one or more of copper, silver and gold.

Further, the metal material also comprises one or more of iron, manganese, chromium, zinc, tin, lead, aluminum, titanium, ruthenium, rhodium, iridium and palladium.

Furthermore, the light wavelength of the light irradiation is 150-1500nm, which covers deep ultraviolet light, visible light and near infrared light, and the light irradiation time is 2-4 h.

Furthermore, in the dissolving process, oxygen-containing gas or chemical substances capable of generating oxygen are added into the photocatalytic selective metal dissolving agent, so that the oxygen capacity in the photocatalytic selective metal dissolving agent is 5-100%; the chemical substance capable of generating oxygen comprises one or more of ozone, hydrogen peroxide or sodium peroxide.

Compared with the prior art, the invention has the following advantages:

(1) noble metals (such as gold and silver) generally exist in a simple substance form in the environment, and the photocatalysis technology can enable the photocatalyst to generate free radical species with oxidation property under illumination to oxidize the noble metals so as to dissolve the noble metals, and is also suitable for common metals (copper);

(2) most noble metal dissolution usually uses aqua regia, but silver cannot be dissolved by aqua regia. The metal dissolved by the aqua regia is not selective and is easy to volatilize, thereby polluting the environment. The used photocatalysis reaction condition is mild, and the metal is selectively dissolved in sequence, and the process has the advantages of being mild, low in reaction solution toxicity, energy-saving, green, environment-friendly, low in cost, convenient to operate and the like, and is suitable for large-scale industrial metal selective dissolving treatment;

(3) generally, precious metals with low dissolving reducibility are dissolved by improving the reducibility through coordination reaction (for example, the chloride ions of concentrated hydrochloric acid in aqua regia are subjected to coordination reaction with metals), and the precious metals are dissolved without selectivity.

(4) Because of different reducibility of various metals, when the method is adopted to dissolve various metals, the sequence of dissolving the metals can be judged according to the difference of the reducibility of the metals, and the dissolution end point is determined according to time or color, so that the different metals are selectively separated, and the separation and purification of the metals are realized. For example, according to the metal ion concentration test at different time points, whether the dissolution of a certain metal is finished can be effectively determined. When the dissolution of a certain metal is determined to be finished, the reaction can be stopped, and the next metal is dissolved after the reaction is separated.

Drawings

FIG. 1 is a graph showing the dissolution ratio of the selective dissolution reactions of three metals in example 1;

FIG. 2 is a graph showing the dissolution ratio of the selective dissolution reaction of various metals in example 2;

FIG. 3 is a diagram showing sample objects before and after the dissolution reaction in example 3.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

Example 1

500mg of a material containing the same amount of copper, silver and gold is dispersed in 50ml of acrylonitrile solution, 50mg of a commercial mixed phase titanium dioxide catalyst is added, ultraviolet light is used for irradiating for 4 hours in the air, the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Fig. 1 is a dissolution ratio curve diagram of selective dissolution reactions of three metals, and it is obvious from ICP test data that the dissolution order of the metals in the liquid is copper, silver, gold, and the ratio of the three metals is increasing (a small amount of solution is taken to evaporate the solvent, and then water with equal solvent amount is added for dilution detection).

Example 2

500mg of a material containing the same amount of aluminum, iron, cobalt, nickel, zinc, palladium, platinum, ruthenium, rhodium and iridium is dispersed in 500ml of an acrylonitrile solution, 50mg of a commercial miscible titanium dioxide catalyst is added, and the mixture is irradiated by ultraviolet light in the air for 4 hours, wherein the metal dissolution rate is 0%.

FIG. 2 is a graph showing the dissolution ratio of selective dissolution reactions of various metals, and it is also obvious from ICP test data that no metal is dissolved in the liquid (a small amount of the solution is taken and evaporated to dryness, and then water with equal solvent amount is added for dilution detection), which illustrates the special selectivity of the method for copper, silver and gold.

Example 3

50mg of a material containing 1% of copper, 1% of silver and 1% of gold was dispersed in 20ml of an acrylonitrile solution, 50mg of a commercial miscible titanium dioxide catalyst was added, and the mixture was irradiated with ultraviolet light for 4 hours in the air, whereby the dissolution rate of the metal was 100%.

It can be seen from FIG. 3 that the samples before dissolution were purple (gold), red (silver) and green (copper), respectively, and the samples after dissolution were all white.

Example 4

500mg of a material containing equal amounts of copper, silver and gold is dispersed into 100ml of an aqueous solution of melamine, 50mg of a commercial miscible titanium dioxide catalyst is added, the mixture is irradiated by ultraviolet light in the air for 3 hours, the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Example 5

500mg of material containing equal amounts of copper, silver and gold is dispersed in 25ml of acetonitrile solution, 50mg of commercial miscible titanium dioxide catalyst is added, the material is irradiated by ultraviolet light in the air for 4 hours, the metal dissolution rate is 91.3%, and the dissolution sequence is copper, silver and gold.

Example 6

500mg of material containing equal amounts of copper, silver and gold is dispersed into 150ml of benzyl cyanide solution, then 100mg of commercial miscible phase titanium dioxide catalyst is added, the mixture is irradiated by ultraviolet light in the air for 2 hours, the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Example 7

500mg of material containing equal amounts of copper, silver and gold is dispersed into 80ml of benzyl cyanide solution, then 50mg of commercial miscible phase titanium dioxide catalyst is added, the material is irradiated by ultraviolet light for 4 hours in the air, the metal dissolution rate is 65.4%, and the dissolution sequence is copper, silver and gold.

Example 8

500mg of a material containing 50% of copper, 25% of silver and 25% of gold is dispersed in 50ml of an acrylonitrile solution, 50mg of a commercial miscible titanium dioxide catalyst is added, ultraviolet light is used for irradiating for 4 hours in the air, the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Example 9

500mg of a material containing 80% of copper, 15% of silver and 5% of gold is dispersed into 90ml of an aqueous solution of malononitrile, 50mg of a commercial miscible titanium dioxide catalyst is added, and the mixture is irradiated by ultraviolet light for 4 hours in the air, wherein the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Example 10

500mg of a material containing 25% of copper, 50% of silver and 25% of gold is dispersed in 220ml of acrylonitrile solution, then 150mg of a commercial miscible titanium dioxide catalyst is added, ultraviolet light is used for irradiating for 4 hours in the air, the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Example 11

500mg of a material containing 5% of copper, 25% of silver and 70% of gold was dispersed in 50ml of an aqueous solution of malononitrile, then 75mg of a commercial miscible titanium dioxide catalyst was added, and the mixture was irradiated with ultraviolet light for 4 hours in the air, with a metal dissolution rate of 100%, and the dissolution sequence was copper, silver and gold.

Example 12

500mg of a material containing equal amounts of copper, silver, gold, iron, cobalt and nickel was dispersed in 50ml of an acrylonitrile solution, 70mg of a commercial mixed phase titanium dioxide catalyst was then added, and the mixture was irradiated with ultraviolet light in the air for 4 hours, with the dissolution rates of copper, silver and gold being 100%, and the dissolution rates of iron, cobalt and nickel being 0%, in the order of copper, silver and gold.

Example 13

500mg of a material containing equal amounts of copper, silver, gold, palladium and platinum is dispersed in 500ml of an acrylonitrile solution, then 85mg of a commercial mixed phase titanium dioxide catalyst is added, the mixture is irradiated by ultraviolet light in the air for 4 hours, the dissolution rate of copper, silver and gold is 100%, the dissolution rate of palladium and platinum is 0%, and the dissolution sequence is copper, silver and gold.

Example 14

200mg of a material containing equal amounts of copper, silver, gold, ruthenium and rhodium is dispersed in 60ml of cyanoacetic acid solution, then 30mg of a commercial mixed phase titanium dioxide catalyst is added, ultraviolet light is used for irradiating for 4 hours in the air, the dissolution rate of copper, silver and gold is 100%, the dissolution rate of ruthenium and rhodium is 0%, and the dissolution sequence is copper, silver and gold.

Example 15

250mg of a material containing equal amounts of copper, silver, gold and iridium is dispersed in 55ml of cyanoacetic acid solution, then 25mg of a commercial mixed phase titanium dioxide catalyst is added, and the mixture is irradiated by ultraviolet light in the air for 4 hours, wherein the dissolution rate of copper, silver and gold is 100%, the dissolution rate of iridium is 0%, and the dissolution sequence is copper, silver and gold.

Example 16

500mg of a material containing equal amounts of copper, silver, gold, aluminum and zinc was dispersed in 150ml of an acrylonitrile solution, 50mg of a commercial mixed phase titanium dioxide catalyst was then added, and the mixture was irradiated with ultraviolet light in the air for 4 hours, with the dissolution rates of copper, silver and gold being 100%, and the dissolution rates of aluminum and zinc being 0%, in the order of copper, silver and gold.

Example 17

300mg of a material containing equal amounts of copper and nickel was dispersed in 250ml of an acrylonitrile solution, 50mg of a commercial mixed phase titanium dioxide catalyst was then added, and the mixture was irradiated with ultraviolet light in the air for 4 hours, the copper dissolution rate being 100% and the nickel dissolution rate being 0%.

Example 18

100mg of a material containing the same amount of silver and palladium was dispersed in 50ml of cyanoacetic acid solution, 50mg of a commercial mixed phase titanium dioxide catalyst was added, and the mixture was irradiated with ultraviolet light in the air for 4 hours, with the silver dissolution rate of 100% and the palladium dissolution rate of 0%.

Example 19

550mg of a material containing equal amounts of gold and platinum was dispersed in 350ml of an aqueous solution of malononitrile, and then 50mg of a commercial mixed-phase titanium dioxide catalyst was added, and irradiated with ultraviolet light in the air for 4 hours, with the gold dissolution rate of 100% and the platinum dissolution rate of 0%.

Example 20

600mg of a material containing equal amounts of copper, silver, cobalt and nickel is dispersed into 50ml of an acrylonitrile solution, then 500mg of a commercial mixed phase titanium dioxide catalyst is added, and the mixture is irradiated by ultraviolet light in the air for 4 hours, wherein the dissolution rate of copper and silver is 100 percent, the dissolution rate of iron and cobalt is 0 percent, and the dissolution sequence is copper and silver.

Example 21

1000mg of material containing equal amounts of copper, silver and aluminum is dispersed into 500ml of acrylonitrile solution, then 100mg of commercial mixed phase titanium dioxide catalyst is added, and the mixture is irradiated by ultraviolet light in the air for 4 hours, wherein the dissolution rate of copper and silver is 100 percent, the dissolution rate of aluminum is 0 percent, and the dissolution sequence is copper and silver.

Example 22

650mg of a material containing the same amount of silver, gold, palladium and nickel was dispersed in 150ml of acrylonitrile solution, then 150mg of a commercial mixed phase titanium dioxide catalyst was added, and the mixture was irradiated with ultraviolet light in the air for 4 hours, wherein the dissolution rate of silver and gold was 100%, the dissolution rate of palladium and nickel was 0%, and the dissolution sequence was silver and gold.

Example 23

350mg of material containing the same amount of silver, gold, ruthenium and iridium is dispersed into 75ml of acrylonitrile solution, then 25mg of commercial mixed phase titanium dioxide catalyst is added, ultraviolet light is used for irradiating for 4 hours in the air, the dissolution rate of silver and gold is 100%, the dissolution rate of ruthenium and iridium is 0%, and the dissolution sequence is silver and gold.

Example 24

780mg of a material containing equal amounts of copper, iron, cobalt and nickel was dispersed in 80ml of an acrylonitrile solution, then 60mg of a commercial mixed phase titanium dioxide catalyst was added, and the mixture was irradiated with ultraviolet light for 4 hours in the air, wherein the copper dissolution rate was 100%, and the iron, cobalt and nickel dissolution rates were 0%.

Example 25

520mg of a material containing equal amounts of silver, aluminum, palladium and ruthenium were dispersed in 50ml of an aqueous solution of melamine, 100mg of a commercial mixed-phase titanium dioxide catalyst was then added, and the mixture was irradiated with ultraviolet light in air for 4 hours, the silver dissolution rate being 100%, and the aluminum, palladium and ruthenium dissolution rates being 0%.

Example 26

660mg of a material containing the same amount of gold, aluminum, nickel and ruthenium was dispersed in 60ml of an acrylonitrile solution, 160mg of a commercial mixed phase titanium dioxide catalyst was then added, and the mixture was irradiated with ultraviolet light for 4 hours in the air, with the gold dissolution rate of 100% and the aluminum, nickel and ruthenium dissolution rate of 0%.

Example 27

Dispersing 120mg of material containing equal amounts of gold, rhodium and iridium into 50ml of acrylonitrile solution, then adding 150mg of a commercial mixed phase titanium dioxide catalyst, and irradiating for 4 hours in the air by using ultraviolet light, wherein the gold dissolution rate is 100 percent, and the rhodium and iridium dissolution rates are 0 percent.

Example 28

250mg of a material containing equal amounts of platinum, aluminum, palladium and ruthenium were dispersed in 150ml of an aqueous solution of malononitrile, and then 50mg of a commercial mixed-phase titanium dioxide catalyst was added and irradiated with ultraviolet light for 4 hours in the air, with the dissolution rates of aluminum, platinum, aluminum, palladium and ruthenium being 0%.

Example 29

550mg of a material containing equal amounts of iron, rhodium and iridium was dispersed in 130ml of an acrylonitrile solution, and then 70mg of a commercial mixed phase titanium dioxide catalyst was added, and irradiated with ultraviolet light in the air for 4 hours, with a silver dissolution rate of 100% and iron, rhodium and iridium dissolution rates of 0%.

Example 30

500mg of materials containing different amounts of copper, silver, gold, aluminum, palladium and ruthenium were dispersed in 50ml of a mixed solution of acrylonitrile, and then 50mg of a commercial miscible titanium dioxide catalyst was added, and irradiated with ultraviolet light for 4 hours in the air, with the dissolution rates of copper, silver and gold of 100% and the dissolution rates of aluminum, palladium and ruthenium of 0%, in the order of copper, silver and gold.

Example 31

500mg of a material containing equal amounts of copper, silver and gold was dispersed in 50ml of acrylonitrile solution, and 50mg of porphyrin-loaded titanium dioxide (TCPP-TiO) was added₂) The catalyst is irradiated by ultraviolet light for 4 hours in the air, the metal dissolution rate is 88.7 percent, and the dissolution sequence is copper, silver and gold.

Example 32

500mg of material containing equal amounts of copper, silver and gold is dispersed in 50ml of acrylonitrile solution, 130mg of commercial cadmium sulfide catalyst is added, visible light with the wavelength of 420nm is used for irradiating for 4 hours in the air, the metal dissolution rate is 78.6%, and the dissolution sequence is copper, silver and gold.

Example 33

Dispersing 500mg of material containing equal amounts of copper, silver and gold into 50ml of acrylonitrile solution, then adding 50mg of self-assembled porphyrin nanosheet (SA-TCPP) catalyst, irradiating for 4 hours in the air by using visible light, wherein the metal dissolution rate is 96.1%, and the dissolution sequence is copper, silver and gold.

Example 34

500mg of a material containing equal amounts of copper, silver and gold were dispersed in 50ml of a phenylacetonitrile solution, and 50mg of oxygen-deficient titanium dioxide (OV-TiO) was added₂) The catalyst is irradiated by visible light for 4 hours in the air, the metal dissolution rate is 86.9 percent, and the dissolution sequence is copper, silver and gold.

Example 35

500mg of a material containing equal amounts of copper, silver and gold were dispersed in 50ml of an acrylonitrile solution, and 50mg of hydroxyl-modified titanium dioxide (OH-TiO)₂) The catalyst is irradiated by visible light for 4 hours in the air, the metal dissolution rate is 93.6 percent, and the dissolution sequence is copper, silver and gold.

Example 36

500mg of a material containing equal amounts of copper, silver and gold was dispersed in 50ml of a phenylacetonitrile solution, and 50mg of molybdenum disulfide-supported titanium dioxide (MoS) was added₂/TiO₂) The catalyst is irradiated by visible light for 4 hours in the air, the metal dissolution rate is 99.8 percent, and the dissolution sequence is copper, silver and gold.

Example 37

500mg of a material containing equal amounts of copper, silver and gold was dispersed in 50ml of an acrylonitrile solution, and 50mg of molybdenum disulfide and cadmium sulfide (MoS) were added₂The catalyst is irradiated by visible light for 4 hours in the air, the metal dissolution rate is 100 percent, and the dissolution sequence is copper, silver and gold.

Example 38

500mg of a material containing equal amounts of copper, silver and gold were dispersed In 50ml of acetonitrile solution, and 50mg of phosphorus-doped indium oxide (P-In) was added₂O₃) Catalyst in airIrradiating with ultraviolet light for 4h, wherein the metal dissolution rate is 97.9%, and the dissolution sequence is copper, silver and gold.

Example 39

500mg of a material containing equal amounts of copper, silver and gold are dispersed in 50ml of an acrylonitrile solution, and 50mg of an organic photosystem and an inorganic compound (PS II/Ru)₂S₃The catalyst is irradiated by visible light for 4 hours in the air, the metal dissolution rate is 100 percent, and the dissolution sequence is copper, silver and gold.

Example 40

500mg of material containing equal amounts of copper, silver and gold is dispersed in 50ml of cyanoacetic acid solution, 200mg of commercial cadmium sulfide catalyst is added, ozone is introduced, visible light with the wavelength of 550nm is used for irradiating for 3 hours, the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

EXAMPLE 41

500mg of a material containing the same amount of copper, silver and gold is dispersed in 50ml of acrylonitrile solution, then 150mg of a commercial mixed phase titanium dioxide catalyst is added, gas with the oxygen proportion of 30% is introduced, ultraviolet light with the wavelength of 365nm is used for irradiating for 3 hours, the metal dissolution rate is 84.9%, and the dissolution sequence is copper, silver and gold.

Example 42

Dispersing 500mg of material containing equal amounts of copper, silver and gold into 50ml of acrylonitrile solution, then adding 95mg of commercial mixed phase titanium dioxide catalyst, introducing gas with the oxygen proportion of 50%, irradiating for 5.5h by using ultraviolet light with the wavelength of 365nm, wherein the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Example 43

Dispersing 500mg of material containing equal amounts of copper, silver and gold into 50ml of benzyl cyanide solution, then adding 80mg of commercial mixed phase titanium dioxide catalyst, introducing gas with the oxygen proportion of 30%, and irradiating for 5h by using deep ultraviolet light with the wavelength of 150nm, wherein the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Example 44

Dispersing 500mg of a material containing equal amounts of copper, silver and gold into 50ml of an aqueous solution of malononitrile, then adding 150mg of a commercial cadmium sulfide catalyst, introducing gas with an oxygen proportion of 60%, irradiating for 6h by using visible light with a wavelength of 550nm, wherein the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Example 45

Dispersing 500mg of material containing equal amounts of copper, silver and gold into 50ml of acrylonitrile solution, then adding 200mg of commercial cadmium sulfide catalyst, adding hydrogen peroxide, irradiating for 6.5h by using visible light with the wavelength of 550nm, wherein the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Example 46

Dispersing 50mg of material containing equal amounts of copper, silver and gold into 150ml of acrylonitrile solution, then adding 50mg of zinc porphyrin (Zn-porphyrin) catalyst, adding hydrogen peroxide, irradiating for 4 hours in nitrogen by using visible light, wherein the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Example 47

500mg of a material containing equal amounts of copper, silver and gold were dispersed in 50ml of an acrylonitrile solution, and 50mg of two-dimensional titanium dioxide (2D-TiO) was added₂) The catalyst is introduced with gas with oxygen proportion of 50 percent, the catalyst is irradiated by visible light with the wavelength of 420nm for 4 hours, the metal dissolution rate is 100 percent, and the dissolution sequence is copper, silver and gold.

Example 48

750mg of a material containing equal amounts of copper, silver and gold are dispersed in 150ml of acrylonitrile solution, and then 250mg of titanium dioxide (H-TiO) rich in trivalent titanium ions are added_2-x) The catalyst is irradiated by 420nm visible light for 4 hours in the air, the metal dissolution rate is 100 percent, and the dissolution sequence is copper, silver and gold.

Example 49

Dispersing 500mg of material containing equal amounts of copper, silver and gold into 50ml of acrylonitrile solution, then adding 50mg of cadmium sulfide quantum dot (CdS QDs) liquid catalyst, irradiating for 4 hours in air by 550nm visible light, wherein the metal dissolution rate is 100%, and the dissolution sequence is copper, silver and gold.

Example 50

500mg of a material containing equal amounts of copper, silver and gold were dispersed in 50ml of a phenylacetonitrile solution, and 50mg of nitrogen-deficient carbon nitride (g-C) was added₃N_x) Catalyst, in air with 550nm visible lightIrradiating for 4h, wherein the metal dissolution rate is 68.7%, and the dissolution sequence is copper, silver and gold.

The above embodiments are merely illustrative of the technical solutions of the present invention, and not restrictive, and those skilled in the art may make changes, substitutions, modifications, and simplifications in the spirit of the present invention and equivalent changes without departing from the spirit of the present invention, and shall fall within the protection scope of the claims of the present invention.