| With the continuous development of global industry,the environmental pollution and the energy crisis have seriously affected the survival and development of mankind,resulting in more prominent energy and environmental problems,the continuous reduction of non-renewable energy sources.The continuous upgrading of environmental pollution,and the continuous development is going away.How to realize turning waste into treasure and the resource utilization of existing energy has become a research hotspot at this stage.As the main component of greenhouse gases,carbon dioxide is also the main carbon source in the atmosphere.The research on the reduction of carbon dioxide to organic compounds can realize the resource utilization of carbon dioxide and has considerable application value.This experiment involves the study of the preparation of photoelectrocatalytic materials and the experimental conditions of the photoelectrocatalytic reduction to reduce the carbon dioxide to ethanol by the catalytic materials.(1)Titanium dioxide nanotubes were prepared by anodic oxidation method.The different proportions of the chemical polishing solution on the titanium polishing effect were compared,the best volume ratio of hydrofluoric acid,nitric acid and pure water in chemical polishing solution were determated.Titanium dioxide nanotubes were prepared by different reaction electrolytes,reaction voltage and reaction temperature.By compared the morphologies of the prepared titanium dioxide nanotubes,the best experimental factors for the preparation of titanium dioxide nanotubes by anodic oxidation were obtained.Experimental results showed that to use the 5wt% ammonium fluoride of ethylene glycol as electrolyte,and 60 v reaction voltage was applied under the 20? reaction temperature,the highly ordered titanium dioxide nanotube arrays can be prepared effectively.(2)The reduction of graphene oxide was made by two steps of modified Hummers Method and concentrated alkali method.The graphite was used as raw material,the graphene oxide was made by modified Hummers Method,then the concentrated alkali condition was used to reduce it.After that the reduced graphene oxide whice is morestable can be made.The reduced graphene oxide was characterized by SEM,TEM and XRD.(3)The reduced graphene oxide/titanium dioxide nanotubes composite was prepared by Anodic Electrochemical Deposition Techniques.Titanium dioxide nanotubes which prepared by anodic oxidation method were used as reaction electrode,the reduced graphene oxide aqueous solution was used as reaction electrolyte,and the constant voltage DC power was used to provide the voltage.Under the action of current,the reduced graphene oxide in the electrolyte migrated to the anode and adsorbed on the surface of the titanium dioxide nanotubes,the reduced graphene oxide/titanium dioxide nanotubes composite formed.The composite was analyzed by SEM,EDS and XRD.Experimental results showed that the composite can be prepared effectively under the 20 v reaction voltage for 6h.(4)The reduced graphene oxide/titanium dioxide nanotubes composite was used to reduce the carbon dioxide to ethanol.The composite was used as the reaction electrode,and 2wt% aqueous solution of sodium bicarbonate was used as the reaction electrolyte,the constant voltage DC power was used to supply the voltage under the UV light irradiation.The ethanol,which was made under the different reaction voltage and reaction temperature,determined by gas chromatography.Experimental results showed that the amount of ethanol produced by photoelectrocatalytic reduction of carbon dioxide is the highest under the 1.5v reduction voltage and the 50 ? reduction temperature,the production of ethanol was 185.08nmol/(h · cm2catalyst).With the increase of reaction time,the amount of ethanol produced by photoelectrocatalytic reduction of carbon dioxide increased continuously.When the reaction time was 10 h,the yield of ethanol produced by photoelectrocatalytic reduction of carbon dioxide was1027.14nmol/cm2 catalyst.Compared the production of ethanol which producted by the composite and the titanium dioxide nanotubes,it showed that the load of the reducted graphene oxide can enhance the efficiency of photoelectrocatalytic reduction the carbon dioxide to ethanol. |
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