The Study On Photocatalytic Reduction Of CO₂ Into Fuels On ZnO Nanoparticles

The emission of CO2 is the main cause of global warming.So,how to control the emission of CO2 effectively is the central issue of research.To solve series of environmental problems which are caused by emission of CO2,the utilization of CO2 is a good method.Because of its soft reaction condition,the photoreduction of CO2 is an method which has a good application prospect.In resent years,represented by Zn O and Ti O2,the semiconductor catalysts are concerned because it is cheap,nontoxic and stable.This paper selected nano-Zn O,prepared by commercial method,as catalyst to photoreduct CO2,and investigated the effects of water bath temperature,reactor temperature,light intensity,CO2 flow and catalyst quality.When the temperature of water bath is 90 degree,the temperature of reactor is 150 degree,the catalyst quality is 0.01 g,the light intensity is 37 m W/cm2,the CO2 flow is 5ml/min,the production of H2,CO and CH4 are maximum.So the best reaction condition was found.Different shape of nano-Zn O were synthesized by hydrothermal method.The samples were characterized by X-ray diffraction(XRD), transmission electron microscope(TEM), UV-Vis diffuse reflectance spectroscopy(UV-Vis) and photoluminescence spectroscopy(PL). Through the result of photoreduct CO2 experiment,the plateslike of Zn O is better than any other shapes.The Ag/Zn O nanocomposites are composed of Zn O nanoplates and met allic Ag nanoparticles attached on the surface of Zn O nanoplates.The Ag/Zn O nanocomposites showed enhanced photocatalytic activity compared with pure Zn O.The photocatalytic performance of the Ag/Zn O nanocomposites with different Ag contents was investigated.With the evolution of the Ag content is 2%, the photocatalytic activity of the Ag/Zn O nanocomposites is the best.