Development And Application Of Down Feather Based Carbon Materials

Based on the"dual-carbon"goal,solar-driven photohot water evaporation technology has broad application prospects in seawater desalination and wastewater treatment for its low cost and environmentally friendly treatment.Because of its high light absorption rate,abundant pore structure,good physical and chemical properties and other characteristics,carbon aerogel has become a highly competitive photothermal conversion material in the solar water evaporation application system.In view of the current complicated preparation process of carbon aerogel,high energy consumption,involving the use of a variety of harmful chemicals and other problems.In this paper,down feather-based carbon（DCFA）aerogel was successfully prepared using the waste down feather as raw material by low-temperature one-step carbonization method.The DCFA was modified by polypyrrole（PPy）and chitosan/polyvinyl alcohol（CS/PVA）hydrogel to achieve highly efficient seawater desalination and wastewater treatment.The main research contents of this paper are as follows:（1）Preparation of down feather-based carbon aerogels and its water evaporation properties.DCFA aerogels was developed using the down feather as raw material by one-step carbonization in nitrogen atmosphere.In the process of carbonization,the intertwined down fiber cluster（DC）shrinked under thermal induction,which further increased the winding between the fibers,forming the DCFA aerogel with self-locked structure.Because the down fibers contain disulfide bonds and amino groups,the DCFA aerogels have unique self-doping characteristics:Large amounts of carbon（>80%）and small amounts of sulfur and nitrogen elements.The low density and high porosity of DCFA aerogel increase the total solar absorbance and inhibit the energy loss during evaporation,the absorbance of the aerogel was as high as 97.03%.The evaporation rate of 3.5 wt%saline and dye wastewater reached 2.05 and 2.11kg·m^-2·h^-1,respectively,which are higher than most reported results.After ten experiments with 3.5 wt%saline and actual dye wastewater,DCFA aerogel maintained good evaporation performance,indicating that DCFA aerogel has the potential for long-term application.（2）Preparation of DCFA/PPy aerogel materials and their water evaporation and heavy metal ion adsorption properties.In order to improve the strength and heavy metal ion adsorption properties of DCFA aerogels,DCFA/PPy aerogels were prepared by solution polymerization.Compared with the DCFA aerogel,the compression strength of the DCFA/PPy aerogel was increased from 0.0035 MPa to 0.007 MPa.When the mass ratio of DCFA aerogel to pyrrole（Py）was 1:3,the water evaporation rate of DCFA/PPy aerogel was 1.96 kg·m^-2·h^-1.The maximum equilibrium adsorption capacities for chromium(Cr⁶⁺),nickel(Ni²⁺)and copper(Cu²⁺)were 12.00 mg/g,10.91 mg/g and 11.81 mg/g,respectively.To further enhance the strength of DCFA/PPy aerogel,DCFA/PPy hydrogels with CS and PVA as the matrix were prepared.DCFA/PPy hydrogel showed higher compression strength（0.04 MPa）and better elastic recovery.The water evaporation rate of DCFA/PPy hydrogel reached 2.160 kg·m^-2·h^-1;the maximum equilibrium adsorption capacities of chromium(Cr⁶⁺),nickel(Ni²⁺)and copper(Cu²⁺)reached 13.95 mg/g,13.05 mg/g and 13.60 mg/g,respectively.In conclusion,this paper adopted simple and efficient low temperature one-step carbonization method to successfully prepare DCFA aerogel with self-locking structure,good photohot water evaporation and heavy metal ion adsorption properties,providing a new idea for the construction of fiber-based carbon aerogel/hydrogel materials and their application in seawater desalination,wastewater treatment and other fields.