Preparation And Properties Of Biomass-based Photocatalytic Composites By Microwave-assisted

Photocatalytic technology has a wide range of application prospects for the degradation of many pollutants.In this paper,two kinds of biomass-based photocatalytic materials were synthesized by microwave-assisted ionic liquid(MAIL)method,and then the structure and properties of the obtained composite were studied.Cellulose/MoS2 composite was prepared by MAIL method using the ionic liquid as reactive medium,cellulose,(NH4)6MO7O24 and thiourea as a precursor.Effect of the types of ionic liquid on the structure and morphology of MoS2 was studied.The structure and properties of the obtained composite were characterized by X-ray Diffraction(XRD),Scanning Electron Microscope(SEM)and Electrochemical Impedance Spectroscopy(EIS)analysis.Results indicated that MoS2 prepared by[BMIM]Cl showed the flower like microspheres stacked by two dimensional nanoscales.The removal efficiency of 20 mg/L MB could reach 96.12%under visible light irradiation,and the degradation ratio of the composite towards MB can still reach 86%,even in the third reuse cycle.Using cellulose/MoS2 composite as photocatalyst,the visible light reduction efficiency of Cr(VI)solution under different conditions were investigated.The results showed that the composite exhibited high photo-activities when citric acid was added as a trapping agent.The photocatalytic reduction ratio of Cr(VI)can reach 96.19%in 180 min when pH=3 and the amount of the composite was 200 mg/L.Composite still showed more than 80%reduction rate after recycling 3 times.Chitosan/TiO2 composites were successfully synthesized by MAIL method using the ionic liquid[EMIM]Ac as reactive medium,chitosan and Ti(OBu)4 as a precursor.The structure and properties of the obtained composite were characterized.Results indicated that the composite prepared by 180? of radiation temperature exhibited excellent photocatalytic performance.The degradation efficiency of RhB(10 mg/L)could reach 84.94%within 90 min under visible light irradiation.In order to further improve the visible light photocatalytic efficiency,chitosan/TiO2/MoS2 composite was obtained by adding self-made MoS2.The effects of MoS2 loading amount on the composites were investigated,and results indicated that the photocatalytic effect was greatly improved when the dosage of MoS2 is 5%.The removal efficiency of RhB(10 mg/L)could increase from 84.94%to 97.91%and the degradation efficiency could increase from 83.87%to 97.9%within 90 min under visible light irradiation.removal efficiency of RhB(10 mg/L)could increase from 84.94%to 97.91%and the degradation efficiency could increase from 83.87%to 97.9%within 90 min under visible light irradiation.Using chitosan-based composite as photocatalyst,the visible light reduction efficiency of Cr(VI)solution were investigated.The results showed that the composite exhibited high photo-activities with the presence of citric acid.With the increase of initial pH and initial concentration of the solution,the removal rate and reduction rate of Cr(VI)decreased.The photocatalytic reduction ratio of composite can reach 100%in 150 min when pH=3,the initial concentration of Cr(VI)was 15 mg/L and the amount of the composite was 400 mg/L.Composite still remained more than 90%reduction rate after recycling 3 times.