Method for preparing cuprous oxide by using coffee liquid and application of cuprous oxide

Abstract

The invention discloses a method for preparing cuprous oxide by using coffee liquid and application of the cuprous oxide, and belongs to the field of green chemistry and photocatalytic degradation. An antioxidant substance in the coffee extract is used as a reducing agent, a traditional cuprous oxide preparation process is improved, an effective method for green synthesis of the cuprous oxide nano material is provided, and the green development strategy of low carbon, low energy consumption and no pollution is met. The method comprises the following steps: grinding coffee beans into powder, adding deionized water, fully heating and stirring, standing and cooling to room temperature, and keeping clear liquid to obtain coffee liquid; and sequentially adding copper sulfate pentahydrate, sodium citrate, sodium hydroxide and coffee liquid into deionized water, heating and stirring until the reaction is finished, cooling to room temperature, washing and drying to obtain cuprous oxide solid powder.

Description

Technical Field

[0001] The invention belongs to the field of green chemistry and photocatalytic degradation Background Art

[0002] In recent years, the chemical industry has played an extremely important role in my country's economic progress, and green chemistry is an inevitable trend for the future development of my country's chemical industry. The core of green chemistry is to minimize the negative impact of chemical production on the environment by designing safe and efficient chemical processes, giving priority to the use of pollution-free or pollution-reducing raw materials in the production process, and at the same time, these products can achieve resource recovery and recycling. Through the technology of green chemistry, not only can the production efficiency of chemicals be improved, but also the environment can be effectively protected, achieving a win-win situation of economic benefits and environmental protection, which is also of far-reaching significance for promoting efficient resource utilization and building an environmentally friendly society. Cuprous oxide is an efficient photocatalyst. As a typical narrow-bandgap p-type semiconductor, its bandgap width is 1.9-2.2eV, which can be excited by visible light and has a high absorption coefficient in the visible light region. Due to its unique optoelectronic properties, non-toxicity, and low preparation cost, it is considered to be a green and environmentally friendly material with great development prospects. Cuprous oxide has great application prospects in the fields of visible light catalytic degradation of organic pollutants, photolysis of water to produce hydrogen, and catalytic oxidation of carbon dioxide.

[0003] The chemical methods for synthesizing cuprous oxide include electrodeposition, hydrothermal synthesis, liquid phase reduction, solvent thermal synthesis, thermal oxidation and microwave assisted heating. When using the traditional chemical reduction method to synthesize cuprous oxide, the commonly used reducing agents include hydrazine hydrate (N 2 H 4 ), ascorbic acid (C 6 H 8 O 6 ), sodium borohydride (NaBH 4 ) etc. Since these chemical reducing agents are expensive and easily pollute the environment, they are not in line with the development direction of green chemistry. In order to overcome the shortcomings of these existing methods, the present invention proposes to apply a green synthesis method, use coffee liquid as a raw material, and prepare and synthesize efficient functional material cuprous oxide. Coffee is a common drink in life, and it is very beneficial to the human body because it is rich in a large amount of caffeine, tannic acid, oil and nitrogen compounds. For example, coffee contains vitamin B and free fatty acids, which promote metabolism and help gastrointestinal digestion; it is rich in magnesium and potassium, which helps insulin regulate blood sugar levels and promotes fat decomposition; and ingredients such as caffeine and tannic acid can relieve fatigue, delay skin aging, and have antioxidant function. The present invention uses antioxidant substances in coffee extract as reducing agents, improves the traditional cuprous oxide preparation process, and proposes an effective method for green synthesis of cuprous oxide nanomaterials, which is in line with the green development strategy of low carbon, low energy consumption and pollution-free. Summary of the invention

[0004] The present invention relates to solving the problem of unavoidable use of toxic and harmful chemical reducing agents in the synthesis process of traditional nanomaterials, thereby proposing a simple, rapid and pollution-free method for realizing green chemical synthesis by using coffee liquid as a raw material for preparing nano cuprous oxide photocatalyst. To solve the above problem, a method for preparing cuprous oxide by using coffee liquid and its application in the present invention are completed by the following steps.

[0005] Step 1: Grind the coffee beans into powder and add deionized water, fully heat and stir, let stand and cool to room temperature, then retain the clear liquid to obtain coffee liquid.

[0006] Step 2: Add deionized water to copper sulfate pentahydrate, sodium citrate, sodium hydroxide and coffee solution in sequence, heat and stir until the reaction is complete, cool to room temperature, wash and dry to obtain cuprous oxide solid powder.

[0007] It is further defined that in step one, 10 to 20 g of coffee powder is added to 80 to 120 mL of deionized water.

[0008] It is further defined that in step 1, the heating temperature is 75-85° C. and the heating time is 20-40 min.

[0009] Further defined, in step 2, 350-400 mg of copper sulfate pentahydrate, 135-155 mg of sodium citrate, 0.8-1.2 g of sodium hydroxide, and 30-80 mL of coffee liquid are added in sequence to 80-100 mL of deionized water.

[0010] It is further defined that the heating temperature in step 2 is 75-85° C. and the heating time is 20-40 min.

[0011] It is further defined that in step 2, the temperature is maintained at 60° C. in a vacuum drying oven for 12 hours.

[0012] The nano cuprous oxide prepared by the method of the present invention does not use the expensive and toxic strong chemical reducing agents commonly used in the traditional nano material preparation process, but uses natural reducing substances in food as raw materials. An environmentally friendly and efficient nano functional material is prepared through a simple, rapid and green nano material synthesis method. The nano cuprous oxide prepared by the method has better photocatalytic activity than the material prepared by the traditional method. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the XRD spectrum of nano cuprous oxide; Figure 2 is the UV-visible absorption spectrum of nano-cuprous oxide; Figure 3 is the optical band gap of nanocuprous oxide; Figure 4 It is the Mott-Schottky test spectrum of nano-cuprous oxide; Figure 5It is the spectrum scanning curve of coffee liquid; Figure 6 This is the time-dependent curve of the photocatalytic reduction degradation of 30mL 40mg / L potassium dichromate indicator by cuprous oxide prepared by traditional process and cuprous oxide prepared by coffee liquid; Figure 7 This is a scanning electron microscope photo of nano-cuprous oxide. DETAILED DESCRIPTION

[0014] Example 1: The preparation of coffee liquid in this example is carried out according to the following steps: grind coffee beans into powder, take 15g of the powder, add 100mL of deionized water, heat and stir thoroughly at 80°C in a water bath heating pot for 30min, let it stand and cool to room temperature, retain the clear liquid, and obtain coffee liquid.

[0015] In this embodiment, the preparation of cuprous oxide using coffee liquid is carried out according to the following steps: 375 mg of copper sulfate pentahydrate, 147 mg of sodium citrate, 1 g of sodium hydroxide, and 50 mL of coffee liquid are added to 100 mL of deionized water in sequence, the heating temperature is 80° C., the heating time is 30 min, the reaction is completed, the mixture is cooled to room temperature, washed, and dried in a vacuum drying oven at 60° C. for 12 h to obtain cuprous oxide solid powder.

[0016] The photocatalytic reduction degradation of Cr(VI) reaction uses a 300W xenon lamp to simulate sunlight. Place 10mg of the catalyst to be tested and 30mL of a 40mg / L potassium dichromate solution in a 100mL beaker. Fix the beaker 5cm in front of the light source and maintain constant magnetic stirring during the degradation reaction. Take the same time interval to detect the absorbance of the reaction solution, and calculate the concentration of the reaction solution to make a curve of the degradation rate changing with the illumination time, so as to analyze and compare the photocatalytic activity of the samples. Figure 6 shown.

[0017] from Figure 6 It can be seen that in the photocatalytic reduction degradation of Cr(VI) by cuprous oxide synthesized by coffee extract in the present invention, the degradation rate reaches more than 98% within 150s, which is significantly improved in terms of the speed and degradation rate of photocatalytic reduction degradation of Cr(VI) compared with cuprous oxide synthesized by traditional methods. It can be seen that the nano cuprous oxide prepared by this method has better photocatalytic activity than the material prepared by traditional methods.

Claims

1. A method for preparing cuprous oxide using coffee liquid and its application, characterized in that The preparation method is completed by the following steps: Step 1, grind coffee beans into powder and add deionized water to fully heat and stir, stand and cool to room temperature and retain the clear liquid to obtain coffee liquid. Step 2, add copper sulfate pentahydrate, sodium citrate, sodium hydroxide and coffee liquid in sequence, heat and stir until the reaction is completed and cool to room temperature, wash and dry to obtain cuprous oxide solid powder.

2. The method according to claim 1, characterized in that In step 1, 10-20 g of coffee powder is added to 80-120 mL of deionized water.

3. The method according to claim 1, characterized in that In step 1, the heating temperature is 75-85° C. and the heating time is 20-40 min.

4. The method according to claim 1, characterized in that In step 2, 350-400 mg of copper sulfate pentahydrate, 135-155 mg of sodium citrate, 0.8-1.2 g of sodium hydroxide, and 30-80 mL of coffee liquid are added to 80-100 mL of deionized water in sequence.

5. The method according to claim 1, characterized in that In step 2, the heating temperature is 75-85° C. and the heating time is 20-40 min.

6. The method according to claim 1, characterized in that In step 2, the temperature is kept at 60° C. in a vacuum drying oven for 12 h.

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