Preparation Of Cellulose Nanofibrils/Reduced Graphene Oxide Composite And Its Application In Triboelectric Nanogenerator

With the rapid development of economy and the continuous progress of science and technology,the energy crisis is an urgent problem to be solved.Traditional fossil energy reserves not only reduce year by year,but also produce haze,acid rain and greenhouse gases,which have a bad impact on the environment.As a kind of clean and renewable energy,self-powered energy system has attracted people’s attention.Triboelectric nanogenerator(TENG)is a kind of self-powered energy which can collect environmental mechanical energy.It can collect biological kinetic energy,wind energy,water energy and other natural environmental energy,and convert it into electrical energy to power electronic devices.As the most abundant green material in the world,lignocellulose has distinct advantages as TENG substrate due to its excellent mechanical properties and surface functional group modifiability.In this work,four kinds of CNF/rGO composites with different structures were prepared by four methods,including cellulose nanofibrils(CNFs)and reduced graphene oxide(rGO).The morphology,chemical composition,thermal properties and mechanical properties of the four composites were analyzed.XPS and ATR-FTIR were used to characterize the surface chemical changes of CNF/rGO composite films,and the connection between CNFs and rGO was discussed.Through the analysis of the thermal and mechanical properties of CNF/rGO composite,the influence of the change of the load of rGO and the connection mode of CNFs and rGO on the properties of the composite membrane was clarified.The results show that the CNF/rGO aerogel composite membrane with a supporting column and two-dimensional layered structure has excellent thermal conductivity.When the rGO load is 1 wt.%,the in-plane thermal conductivity is as high as 16.304 W/m·K.At the same time,the CNF/RGO aerogel composite membrane has rough surface structure,porous internal structure and rich surface polar functional groups.It is an ideal material for preparing TENG friction layer.The CNF/rGO aerogel composite membrane and the perfluoroethylene propylene copolymer(FEP)film were used as the friction layer respectively,and a windmill driven TENG device was designed.The influence of wind speed on the electrical output performance of TENG is studied.Under the working mode of contact separation and relative sliding,the output open circuit voltage of TENG device can reach 77 V under stable operation.Through the analysis of the contact separation and relative sliding principle of the TENG,the mechanism of TENG energy gathering was revealed,and the mechanism of CNF/rGO aerogel composite membrane to enhance TENG performance was elucidated.This work realizes the collection of wind energy driven by breeze force,and expands the application space of TENG as a kind of self-powered energy in human living environment.In this paper,the development of TENG friction materials and the structural design of TENG devices are studied,which provides basic insights for TENG to collect wind energy.Efforts have been made to clean and renewable energy materials,providing new ideas for the future development of self-powered energy systems.