Preparation Of Graphene-based Composites And Adsorption Properties Of Toluene

As the pillar industry in China,the petrochemical industry emits volatile organic waste gas（VOCs）to the atmosphere due to the need for production process,making the air pollution increasingly serious.It is significant to solve the problems caused by volatile organic waste gases.The method of adsorption is a convenient,simple,recyclable method and the adsorbent is the key for the adsorption method.Therefore,it is imperative to develop effective adsorbents.In this paper,three adsorbents were prepared and its adsorption of toluene were analysed.（1）The graphene oxide was prepared Hummers oxidation method.The graphene obtained by reduction was modified by KOH.The Cu-BTC@GO composite was prepared by hydrothermal method and their characterization were studied.（2）The graphene oxide and Cu-BTC@GO composite were used as adsorbent to study the adsorption property of toluene under different toluene concentration,temperature and adsorbents weight.（3）Modified graphene was used as adsorbent to study the effects of KOH concentration,ultrasonic time and temperature for toluene adsorption property.The conclusion as follows:（1）The specific surface area of GO is 300.47 m²·g^-1 and the pore size is concentrated between 2-8 nm.The equilibrium adsorption amount by GO was82.13 mg·g^-1 when the toluene concentration is 1300 mg·m^-3,adsorption temperature is 25℃,adsorbent weight is 0.3 g.The adsorption isotherms of toluene can fit both Langmuir Isotherm and Freundlich Equation but the Freundlich Isotherm is better.（2）The adsorption capacity of the Cu-BTC@GO composite is 183.6 mg·g^-1 when the GO content is 20%,the toluene concentration is 1300 mg·m^-3,adsorption temperature is 25℃,adsorbent weight is 0.3 g.The Freundlich model is more suitable to describe the adsorption for toluene moleCules on Cu-BTC@GO composite.The adsorption kinetics of toluene on Cu-BTC@GO composite was in accordance with the pseudo-second-order adsorption kinetics model.（3）The adsorption capacity of modified graphene is 212.75 mg·g^-1 when the KOH concentration is 6mol·L^-1,the modification temperature is 25℃,the ultrasonic time is 3 h.The adsorption kinetics of toluene on modified graphene was in accordance with the pseudo-second-order adsorption kinetics model.（4）Cu-BTC@GO composite has high recycling efficiency and the adsorption efficiency can reach 82.1%after 5 times cycle experiment.