Study On The Photocatalytic Properties Of Cu₂O And Composites

In recent years, photocatalyst Cu2 O has been widely studied owing to its good properties. It has several advantages such as simple preparation, nontoxicity, low cost and narrow forbidden band, so it can apply natural light. Due to its special properties, the application in photocatalytic process is of great potential. In this paper, glucose was chosed as reducing agent, Cu2 O and its related complexes were synthesized with a wet chemical reduction method. The properties of Cu2 O in the photocatalytic degradation of organic pollutants and the electrochemical reduction of carbon dioxide were investigated. The X-ray diffraction(XRD) and Scanning electron microscopy(SEM) were used to study the crystal structure and the morphology of the synthesized microparticles.1. By orthogonal experiments, the degredation rate of Methylene blue solution was used as the judgement, the optimum technological conditions for the preparation of Cu2 O were as follows: temperature is 60 °C, time is 40 min, sodium hydroxide concentration is 3mol/L.2. Cu2O-WO3 was synthesized by WO3 modification. The photocatalytic properties of degradation of methylene blue by Cu2O-WO3 and Cu2 O were investigated. The results indicated that compared with Cu2 O, Cu2O-WO3 has better photocatalytic performance and recycling performance.3. The catalytic properties of different electrodes with different materials deposited on it were investigated by cyclic voltammetry, the result of cyclic voltammograms showed that electrode made from nickel foam had excellent ability in photoelectrochemical reduction of CO2, the photoelectrochemical efficiency of Cu2 O and its composites were different, the results were as follows: Cu2O-Ti O2<Cu2O-PANI<Cu2O<Cu2O-WO3.4. The effects of different load on the photoelectric properties of nickel foam electrode were investigated by cyclic voltammetry, the results of cyclic voltammograms showed the more the catalyst materials were loaded on nickel foam, the less the photoelectrochemical efficiency in reduction of CO2 was. The reason is the nickel foamhas special porous structure, if the load is excessive, the load of catalyst material will jam the porous structure, which will reduce the contact area of the rection, so the photoelectric catalytic efficiency will decrease.5. The photochemical reduction of carbon dioxide(CO2) using Cu2 O was investigated, in the photocatalytic reaction, the production formaldehyde reached 67μg after 6h per gram catalyst.6. The photoelectrochemical reduction of carbon dioxide(CO2) was investigated in KHCO3 solution saturated with CO2. The nickel foam was chosed as substrate of electrode, Cu2O-WO3 was deposited on it. The results showed the photoelectric catalysis reaction had better performance than photocatalytic reaction. In the photoelectric catalysis reaction, 1g Cu2O-WO3 catalyst was used, after 2h the production formaldehyde reached 126μg, the production methanol reached 386.5μg.