Synthesis And Photothermal Steam Generation Of Self-floating Carbon And Graphene/carbon Membranes

Solar steam generation is an efficient way for solar energy utilization,and has a great application prospect in sea water desalination and sewage purification.Various materials have been proven to be capable of absorbing light and converting light to heat for water steam generation.Among all these materials,carbon-based materials have attracted extensive attention because of the wide light absorption and excellent stability under strong illumination.However,the carbon-based evaporators also perform the shortcomings of unavoidable decompaction and shedding.On the other hand,the photothermal materials are required to float on the water while working to maximize the use of solar energy.So most of the photothermal materials need to be modified by polymer hydrophobic agents or introduce a supporting substrate to gain the self-floating ability.Nevertheless,the hydrophobic agents always suffer from the oxidation and decomposition under long-time or intense illumination.And the preparation of self-floating substrate with steam channels is always complicated.It is still highly challenged to develop a new kind of carbon-based material with self-floating ability,low cost and easy-preparation for solar steam generation.The main research contents are summarized as follows:(1)With the intention of sustainable economy,we design a new photothermal membrane by the carbonization of low-cost and scalable commercial facial tissue.The carbonized tissue membrane can self-float on the water without any assistance.And the carbonized tissue performs a high evaporation efficiency of 95 % under 3-sun illumination and outstanding stability for 80 cycles.The easy-preparation,self-floating ability,high evaporation efficiency,and the excellent stability make the carbonized tissue membrane meet the requirements of the practical production on a large scale.(2)With commercial tissue as the main precursor,GO/cellulose membranes were obtained by freeze-drying,and then the integrated RGO/C photothermal membranes were synthesized by self-reformed double-layer tubular furnace.By adjusting the amount of RGO,RGO/C photothermal membranes can achieve the optimum value of absorption.It is proved that RGO/C membrane is an efficient photothermal material.In this work,the composition,spatial structure and self-floating of carbon membranes and RGO are coordinated,which provides a new idea for the study of carbon-based photothermal conversion materials.