Fundamental Research On Graphene-based Materials Applied In The Field Of Environmental Governance

In this paper,basic research on the application of graphene-based materials in the field of environmental governance was carried out from the following three aspects:graphene-based materials for the treatment of spilled crude oil of high viscosity,TiO₂/ZIF-8@graphene composites for photocatalytic degradation of toluene gas,and graphene fibers@ZnO for degradation of toluene gas.Heating under low solar radiation intensity is demonstrated to facilitate the cleaning of crude oil by the hydrophobic nanocomposite adsorbents of reduced graphene oxide（RGO）melamine sponge（MS@RGO）foams.The heat generated by the irradiation reduces the viscosity of the crude oil,consequently increases the oil-diffusion coefficient in the pores of the MS@RGO foams and speeds up the oil-sorption rate.Even under the solar radiation intensity as low as 2 k W/m²,the temperature of crude oil rapidly rises to 68°C or higher within 10 min.It only takes 29 s to completely absorb 6 g crude oil at 60°C by 3 tiny pieces of MS@RGO foams.This work makes better use of the excellent photothermal conversion characteristics of crude oil,and its photothermal conversion mechanism under simulated solar radiation is also discussed.This methodology can be adopted to clean up viscous crude oil or extract other chemicals effectively in a large scale,and provides a complete solution for the clean-up of crude oil on the sea or the beach from scientific principles to engineering applications.TiO₂ has the characteristics of photocatalysis,and semiconductor-MOPFs hybrid photocatalyst has attracted more and more attention because of its enhanced photocatalytic activity.TiO₂ inorganic fibers were prepared by electrostatic spinning and grown on the surface of zif-8.Then graphene nanoparticles were grown on the surface of the above materials to obtain TiO₂/ZIF-8@graphene triplet composites.The effects of material ratio,dosage,growth rate and reaction time on degradation rate of photocatalyst were studied.The results showed that with the increase of photocatalyst reaction time and mass,the degradation rate of toluene was higher and higher,and the photocatalytic effect of TiO₂ was significantly improved by graphene.Graphene fibers with good toughness and structure were prepared by microfluidic spinning technology,and then ZnO nanorods were grown on it by hydrothermal method to obtain a composite material of graphene fibers/ZnO nanorods.The efficiency of the composite in toluene removal under UV irradiation was tested.The results revealed that the catalyst had good performance in photocatalysis,and the photocatalytic degradation rate reached 98.3%.