Preparation Of Graphene And Its Application On Solar Vapor Generation

The solar energy is a new type of renewable energy,which has lots of advantages like widespread,large energy and environmental protection.If the solar energy could be wide used in future,it can become the main energy of mankind.And it will ease the current energy tensions.At present,There are two main ways to use the solar energy,one is solar photovoltaic electric,the other is solar thermal conversion.The effciency of Solar photothermal conversion was determined by the absorption capacity of the refrigerant.So it is important to find a high absorption refrigerant to improve the efffciency of the direct solar collectors.The graphene is a new type of two-dimensional nanomaterials with excellent optical,thermal,mechanical and electrical properties which has broad application prospects in solar thermal conversion,optical drive evaporation and photocatalysis.The main research object of this paper is preparation of graphene,and designing experiment to analyse the characteristics of photothermal conversion and the solar steam generation.The graphene was prepared by the ascorbic acid,then the graphene was test to verify the quality.The method would be adjust to make sure the quality of graphene which we made.This step is necessary for the futher experiment.The results show that the graphene nanoparticles which were prepared by the reduction of graphene oxide by ascorbic acid have good stability.The graphene nanofluid was made by the graphene nano particles.And the concentrations of the nanofluid were different to study the influence of absorbing with different concentration of nanofluids.The stability of the nanofluid is very important to measure the performance.The stability of the nanofluids was characterized by the absorbance analysis method,the concentration of the nanofluid can measure the stability of the nanofluid by the UV-Vis spectrophotometer.The thermal and evaporative experiments were carried out on the home made experimental device.And the corresponding calculation model was established to analysis the experimental data.The temperature rise law and evaporation law of the graphene nanofluids were obtained by temperature and mass change which measured by experiment.The absorbing effective of the nanofluid can be calculated.The effects of different light intensity and thermal evaporation of graphene nanofluids were investigated by changing the experimental conditions.The results show that with the lower concentration of nanofluids,the collector efficiency was higher than the evaporation efficiency.When the concentration of nanofluids increased,the evaporation efficiency was higher.Film absorbing material is a new kind of way about solar absorption.The graphene-filter is a kind of Film absorbing material.Tt was prepared by pre-prepared graphene with acuum filtration.The graphene-filter was subjected to photothermal evaporation experiment on the experimental device.The experiment date of the graphene-filter was measured by measuring the temperature and mass change.And the influence of different light intensity on the photothermal evaporation of graphene-filter was studied by changing the experimental conditions.The effects of different graphene nano particle for the photothermal evaporation of graphene-filter were studied.At the same time,the difference between light and heat evaporation experiment of graphene nanofluids is analyzed,and the difference between them was analyzed.The results show that the graphene-filter has good absorption capacity when the content of graphene is low,and the collector efficiency is higher than the evaporation efficiency.with the increased of graphene content,the evaporation efficiency of the graphene-filter are higher.Compared with graphene nanofluid,graphene-filter has better evaporation performance in the process of direct absorption of solar energy.