Study On The Preparation Of Porous Carbon Materials From Lotus Leaves And Their Superelectric And Electrocatalytic Properties

Human beings consume a lot of energy in various applications and cause serious water pollution problems.Energy from fossil fuels has been unable to meeting the growing global energy demand.Therefore,renewable and green energy technologies must be developed.As a renewable raw material widely existed in nature,biomass is widely used as the biomass carbon electrode material for supercapacitor and electrocatalytic degradation of phenol due to its simple synthesis method,low price and good electrical conductivity.In this paper,lotus leaves were used as raw materials to prepare lotus leaves porous carbon materials,and the performance of supercapacitors and electrocatalytic degradation of phenol were studied.In this study,the lotus leaves porous carbon material was prepared by KOH activation method.The supercapacitor properties of the lotus leaves porous carbon material prepared at different calcination temperatures and activation ratios were studied.It was found that lotus leaves porous carbon materials were mesoporous and microporous coexisting porous carbon materials with lamellar structure.This structure can not only improve the adsorption capacity of materials,but also help to improve the electron transport rate.The specific surface area of the LLPC-800-1:3 sample reached2488 m² g^-1,the pore volume was 1.14 cm³ g^-1,and the micropore volume was 0.61 cm³g^-1.The material demonstrated a high capacitance of 379 F g^-1 at 1 A g^-1.The material exhibited good cycling stability and a capacitance retention rate of 90%after 5000charge/discharge cycles.As the electrode material of supercapacitor,the carbon material shows good tolerance.In order to study the electrocatalytic properties of the lotus leaves carbon material,the lotus leaves porous carbon material was prepared by N-doping,template method and acid alkali method,and the best preparation method was preferred.The lotus leaves porous carbon material were prepared by the acid alkali method.Through changing the calcination temperature and the activator content,the lotus leaves porous carbon cathode material having the best electrocatalytic degradation of phenol is preferred.When the 5%concentration activator was added and the activation temperature was800°C,the prepared lotus leaves porous carbon cathode material exhibited the best electrocatalytic degradation of phenol.At this time,the highest production of hydrogen peroxide and·OH was obtained.When the initial concentration of phenol was 100 mg L^-1,the current density was 30 mA cm^-2,and the concentration of Na₂SO₄ electrolyte was 0.10 mol L^-1,and the initial pH value is constant,the degradation rate of phenol by the lotus leaves porous carbon cathode material reached 95.6%.