Research Of Hybrid Nanogenerators Driven By Water Evaporation

The ambient thermal energy is a type of ubiquitous,renewable green energy in the natural environment.Hydroelectric effect is a phenomenon in which water energy is directly converted into electrical energy through the interaction of nanomaterials with water.In recent years,it has been found that the hydroelectric generator based on nanomaterials can convert ambient thermal energy into electricity,especially the hydroelectric nanogenerator driven by the natural water evaporation has been demonstrated to be significant potential.Nanomaterials were used to prepare water evaporation driven nanogenerators,most of which were stacked by nanomaterials.In this way,the bonding force between the nanomaterials in the generator was not strong and the mechanical strength of the generator was poor.In complex working conditions,such as large deformation,water flushing or wearable process,nanomaterials in the generator were easy to fall off.In addition,most researchers used a stationary tank to hold water for the evaporation driven nanogenerator,which was too unwieldy to facilitate the preparation of portable or wearable water evaporation driven nanogenerators.To achieving the practical application of water evaporation driven nanogenerators in the field of flexible,mobile and wearable electronic devices,it was required that nanogenerators have desirable mechanical stability,flexible and mobile water supply devices.In this thesis,a hybrid preparation technology of water evaporation driven nanogenerator was proposed,which used organic binder to improve the mechanical strength of water evaporation driven nanogenerator and realized the function of mobile self-water supply of the generator.The spherical Si O₂nanoparticles were used as the electricity generation materials for the nanogenerator,the nanogenerator made of Si O₂nanomaterials were compared with hybrid nanogenerator.In the hybrid nanogenerator,glass fibers were selected as the support skeleton of the generator,polyvinylidene fluoride（PVDF）was used as an effective binder to bond glass fibers and Si O₂nanoparticles effectively.By adjusting the preparation process and preparation parameters,part of the surface of Si O₂nanoparticles were effectively bonded by PVDF,and part of the surface of the nanoparticles was exposed to ensure that they interact with water to generate streaming potential.Flexible sponge was used to prepare mobile water supply systems instead of unwieldy fixed water tank.The water storage device could be bent arbitrarily,light and compact,and could be integrated with the water evaporation driven nanogenerator to realize the mobile self-water supply of the generator.The nanogenerator with flexible self-water supply device showed ideal mechanical stability,flexibility and electricity output.The open circuit voltage(V_oc)of an individual hybrid nanogenerator prepared by this technology can reach 1.5 V,and the short circuit current(I_sc)can reach 1.45μA,as a result,the maximum output power can reach 0.45μW.As an application example,the electric watch continuously powered with our wearable generators was successfully demonstrated during the model walking process.The technology provides an effective strategy for the stable supplication of removable generator driven by water evaporation,and will greatly widen water evaporation driven nanogenerators adaptability to complex working environment.