A Study Of Photoelectric Synergy Reduction Of CO₂ Based On In₂S₃ Nanomaterial

With the content of CO₂ in the atmosphere continuing to rise in recent years,the problems of environment become more and more obvious.The CO₂ is the main component of greenhouse gas,and the greenhouse effect is becoming more and more serious.In addition to acidification and melting glaciers,such problems as serious natural disasters are also getting worse and worse.The traditional processing method to CO₂ has some positive effect,there are too much energy consumption and secondary pollution.There are many advantages for photoclectric catalytic reduction,such as,high efficiency,less energy consumption and no secondary pollution.The key to the photoelectric catalytic reduction of CO₂ is choice of catalysts.CO₂ is characterized by linear type,dipole moment is zero,very stable and must pass through activation to participate in a variety of reactions.It is very imporment to look for appropriate photoelectrocatalyst.The reticulated vitreous carbon?RVC?has many advantages,for example,high electrical conductivity and light transmission,low density,high strength,large specific surface area and corrosion resistance and so on,it is very suitable as the career of electrode.The RVC has high electrical conductivity,the ability of Catalying reduction of CO₂ is poor.It is very necessary to compostie other materials and accomplish the catalytic reaction efficiently.We successfully prepare In₂S₃ NFs/RVC,In₂S₃ NPs/RVC and DyInS₃ NPs/RVC through design and inquiry and apply them to the experiment of catalytic reduction for CO₂.In₂S₃ as a kind of n-type semiconductor material,it's relatively low energy gap and able to absorb more visible light.As a photosensitive material,it has been widely applied to the battery and TV picture tube,etc.We use thiourea as the source of sulfur,InCl₃·4H₂O as the source of Indium and hydrothermal synthesis method and the In₂S₃ nano flowers?In₂S₃ NFs?is prepared by the control of reaction time and temperature.Then we can load it on the RVC by impregnation method for the study on photoelectric catalytic reduction for CO₂.Through the experiment,we can learn that although its photoelectric catalysis for CO₂ is very obvious,the photoelectric conversion efficiency and the product yield are low.The size,shape and crystal structure of the material have important influence on its property.And it is closly connected with the synthetic method and conditions.In order to make efficient catalytic ability In₂S₃ nanomaterial prepared for CO₂,we can use diphenyl thiourea as the source of sulfur and solvent thermal interface method to make the In₂S₃ nanomaterial tend to grow onoil-water interface.Finally,we prepare the In₂S₃ nanoparticles?In₂S₃ NPs?Which have obvious photoelectric catalysis effect,and then composite it with the RVC.Through the experiment,we can discovere that the photoelectric conversion efficiency improves 23% and the yield of methanol that is the main reduction product increases 1.4 times.The photoelectric catalytic effect of the In₂S₃ NPs/RVC has been further enhanced,due to the poor electrical conductivity of the In₂S₃,the photoproduction and reduction electronic will not be able to get good transmission.In order to improve the catalytic electric activity of the electrode,we make the Catalyst modified by doping rare earth element Dy.In the solvent thermal interface reaction,we dope the Dy³⁺ with In³⁺ according to mole ratio of 1:1.In this way,the material DyInS3 nanospheres?DyInS3 NPs?is prepared and its diameter of 25 nm.Through the photoelectric catalysis performance study of DyInS3 NPs/RVC we can find that by doping Dy,the electrode resistance has greatly reduced,the faraday current efficiency has been increased to 55.3% from 25.9%,the energy gap has been reduced to 1.78 eV,in addition,the reduction product of methanol production rate is as high as 12.35 mmol L-1cm-2.From the research of the DyInS₃ NPs/RVC composite electrode,we can learn it has mang advantages,such as stable performance,high conversion rate and long cycle life,etc.At the same time,it can provide certain theoretical basis for the next step of CO₂ catalysis study.