Research On The Design And Application Of Vertically Aligned Acetate Fiber-based Photothermal Conversion System

The shortage of fresh water resources and the traditional energy crisis have become two thorny issues facing the world.As we all know,the earth is rich in sea water resources,and solar energy is an economical,green and renewable energy.Therefore,the solar-driven interface water evaporation system,as a pollution-free and sustainable way of photothermal water purification,has attracted widespread attention and provides a new way to achieve high-efficiency photothermal conversion efficiency.The use of solar interface water evaporation technology to desalinate seawater and sewage is an ideal way to obtain clean water,but the accumulation of salt or pollutants at the photothermal interface will seriously inhibit the generation of steam,resulting in a decline in the performance of the evaporator.Most of the evaporators with self-cleaning ability have problems such as complicated preparation process,low water delivery efficiency,and large heat dissipation.Acetate fiber has simple preparation process,strong water conductivity,and low thermal conductivity.It is an ideal material for preparing solar interface evaporators.In this paper,the vertically arranged cellulose acetate is used as the carrier,and the carbon dots and Cu₄O₃ stabilized by the carbon dots are used as the photothermal agent.While increasing the water evaporation rate,two application areas of high-concentration seawater desalination and sewage treatment have been studied separately.The main research content and results have the following two aspects:(1)Using coal pitch carbon quantum dots as the photothermal agent,the photothermal agent is uniformly assembled on the surface of the vertically arranged acetate fiber through the method of gradually removing the solvent,and a stable solar interface evaporator is obtained through surface carbonization.The evaporator has high light-to-heat conversion performance under the action of carbon quantum dots,and further improves its light absorption capacity after surface heat treatment.Compared with conventional carbon materials,its evaporation performance is significantly improved,the water evaporation rate is 2.6 kg m^-2 h^-1,and the light-to-heat conversion efficiency is 93.9%.In the simulation experiment of seawater desalination,the evaporator can still maintain a stable water evaporation rate in a 20 wt%high-concentration Na Cl solution,and in a long-term test,no salt will be detected at the photothermal interface.Using Darcy's formula,the influence trend of fiber tortuosity on the salt tolerance of the evaporator was inferred.The above results show that the solar interface water evaporation device with vertical pore structure and good water passage may have better salt tolerance.(2)The solar interface water evaporation device using vertically arranged cellulose acetate as a carrier has better salt tolerance,and we have further explored its treatment performance of volatile organic matter in sewage purification.We are Under CDs stability,the Cu₄O₃ composite was used as the photothermal agent,and the vertically arranged cellulose acetate was used as the carrier to prepare a new evaporator,and the surface treatment process was further improved in the form of gel,so that the photothermal agent attachment was more stable and difficult Fall off.In its purification experiment of pollutants,firstly,o-phenylenediamine was used as the pollution substrate,and the photocatalytic test was carried out with a photothermal agent,which proved that it has a good catalytic effect on o-phenylenediamine.In the photothermal experiment,the evaporator showed a better complete removal effect for o-phenylenediamine.Next,we used phenol,a volatile organic matter,as a pollution source to conduct a water evaporation test,which also showed a good purification effect,with a removal rate of 80%.This is mainly due to the highly efficient adsorption effect of the vertically arranged cellulose acetate.In addition,the evaporator has excellent water evaporation rate and cycle stability,and has application potential in the treatment of long-term volatile pollutants.