| At present,people’s live has serious pollution to the water environment.In order to solve the problem of water pollution,the general treatment methods include photocatalytic oxidation,adsorption separation treatment and bioremediation.From the perspective of resource conservation and environmental remediation,it is a green and safe water treatment method.Hematite(α-Fe2O3)is an n-type semiconductor with low cost,good chemical stability,corrosion-resistant candle,non-toxic,good dispersibility,coloring power and ability to absorb ultraviolet rays.Therefore,nano-Fe2O3 has great practical and theoretical value in the field of photocatalytic degradation of organic pollutants.Cuprous oxide(Cu2O)is a rare narrow band gap(2.2ev)semiconductor that can be excited by visible light.It is rich in raw materials,low in price and stable in nature,and has great application value in photocatalysis.However,the disadvantages of easy to inactivated cuprous oxide and high recombination rate of ferric oxide carriers limit their application in the field of photocatalysis.In this paper,we try to combine the two to form a p-n heterostructure,hinder its carrier recombination,and improve quantum efficiency.The research contents are as follows:1.Using tetrabutyl titanate and copper acetate as raw materials,citric acid and glucose as reducing agents,a Cu2O/TiO2 composite photocatalyst was prepared by hydrolysis and characterized by XRD and SEM characterization.With Cu2O/TiO2 as photocatalyst,the effects of reaction time,initial concentration,catalyst dosage,initial pH and temperature on the decolorization rate of photocatalytic degradation of methylene blue were investigated.The results showed that under the irradiation of a high-pressure mercury lamp,0.01 gCu2O/TiO2 was used as the photocatalyst,and 100mL of a 10mg/L methylene blue solution was used as the simulated wastewater.The pH was 7.0,and the photocatalytic reaction was performed at 25℃ for 60 min.The pH was adjusted to 7.0 and methylene blue was decolorized.The rate can reach 94.38%,and its decolorization kinetics reaction is a quasi-first order process.2.Copper acetate was used as the copper source,ethanol and water were used as the solvent,and a small amount of acetic acid was used as the reducing agent to synthesize nano Cu2O under hydrothermal conditions at 200℃ for 12 hours.In the same way,Fe2O3 and Fe2O3/Cu2O composite catalyst were synthesized by means of ferric chloride.The molar ratio of copper acetate to ferric chloride was changed,whether acetic acid or sodium acetate was added or not,the type of iron salt was changed,and the synthesized product was characterized by means of X-ray powder diffractometer(XRD)and scanning electron microscope(SEM).It was found that using copper acetate and ferric chloride as precursors,the photocatalytic effect was the best when the copper-iron ratio was 7:1.3.Three different morphologies of α-Fe2O3 particles were prepared by different methods.The photocatalytic performance of the three α-Fe2O3 particles was compared by XRD,SEM,XPS,and Uv-sis characterization and photocatalytic testing,and the best was selected for synthesis Cu2O/α-Fe2O3 photocatalyst.A Cu2O/α-Fe2O3 photocatalyst was prepared by chemical deposition,and its characterization test was conducted to explore the effect of the composition of Cu2O with different ratios on the photocatalytic performance of α-Fe2O3 particles.The photocatalytic results show that when α-Fe2O3 is combined with Cu2O,the photodegradation rate of Congo red solution is significantly improved.The effects of reaction time,initial concentration,catalyst amount,initial pH and temperature on the photocatalytic degradation of Congo red were investigated. |
