CN-116747805-B - Photo-thermal conversion aerogel and preparation method and application thereof

CN116747805BCN 116747805 BCN116747805 BCN 116747805BCN-116747805-B

Abstract

The invention provides a photo-thermal conversion aerogel, and a preparation method and application thereof. The invention takes tea slag as a raw material and is treated by alkali liquor to obtain tea slag fibers, the tea slag fibers are calcined at high temperature to obtain carbonized tea slag, the tea slag fibers and the carbonized tea slag are added into sodium alginate solution, the tea slag fibers and carbonized tea slag aerogel are obtained through liquid nitrogen freeze drying, the tea slag fibers and the carbonized tea slag aerogel are soaked in CaCl 2 solution to be crosslinked, and the photo-thermal conversion aerogel based on all biomass wastes is obtained through liquid nitrogen freeze drying.

Inventors

XIONG JUN
HAN CHENXI
WU YUMING
LI MING
YANG ZHIHUI
ZHONG XIN
MIN XUE
WANG WEIMING
PENG JUNJUN

Assignees

武汉纺织大学

Dates

Publication Date: 20260505
Application Date: 20230721

Claims (3)

1. The preparation method of the photo-thermal conversion aerogel is characterized by comprising the following steps of: Adding tea leaves residues into alkali liquor, reacting for 4-8 hours at 150-170 ℃, filtering, and washing to neutrality to obtain tea leaves residue fibers, wherein the mass volume ratio of the tea leaves residues to the alkali liquor is (3-7) g (50-100) mL, the alkali liquor comprises at least one of NaOH solution and KOH solution, and the concentration of the alkali liquor is 0.5-2 mol/L; Calcining the tea residue fibers in a tube furnace at 500-700 ℃ for 1-3 hours to obtain carbonized tea residues; Grinding carbonized tea leaves into powder, adding the powder into acid liquor, soaking for 1-3 hours, and washing to neutrality to obtain tea leaves residue carbon powder, wherein the acid liquor comprises at least one of HCl solution, H 2 SO 4 solution and HNO 3 solution, and the mass concentration of the acid liquor is 2-20%; Adding sodium alginate into water, adding tea dreg fibers, adding tea dreg carbon powder, stirring, freezing and solidifying, and freeze-drying in a freeze dryer to obtain aerogel, wherein the mass ratio of the sodium alginate to the water to the tea dreg fibers to the tea dreg carbon powder is (0.3-0.7), and the mass ratio of the sodium alginate to the water to the tea dreg fibers to the tea dreg carbon powder is (20-30), and the mass ratio of the sodium alginate to the water to the tea dreg fibers to the tea dreg carbon powder is (2-6) to 0.05; And soaking the aerogel in CaCl 2 solution, washing, and freeze-drying in a freeze dryer to obtain the photo-thermal conversion aerogel, wherein the mass concentration of the CaCl 2 solution is 3-7%, and the soaking time is 10-15 h.
2. A photothermal conversion aerogel prepared by the method of claim 1.
3. Use of the photo-thermal conversion aerogel prepared by the preparation method of claim 1 in the preparation of solar evaporators and sea water desalination.

Description

Photo-thermal conversion aerogel and preparation method and application thereof Technical Field The invention relates to the technical field of aerogel, in particular to photo-thermal conversion aerogel and a preparation method and application thereof. Background Fresh water shortage, energy crisis and environmental pollution are urgent challenges facing current humans. The seawater occupies 97% of the earth water resource, and the problem of shortage of global water resource can be effectively relieved by the seawater desalination technology. However, conventional methods of desalination of sea water, such as thermal distillation and reverse osmosis, consume large amounts of energy, further exacerbating the energy crisis. In 2014, interface solar-driven desalination of sea water was proposed as a promising solution to this problem, which has attracted considerable attention due to its high evaporation rate and environmental friendliness. Interface solar driven desalination systems typically include a photo-thermal material, a thermal insulation layer, and a water transport. The photo-thermal material can absorb sunlight and convert the sunlight into heat energy, and the heat insulation layer limits the heat energy from being dissipated into a large amount of water at the water-vapor interface. The water conveyer is used for conveying water to the surface of the photo-thermal material for evaporation. Photothermal materials are largely divided into four classes, plasma, semiconductor, polymer, and carbon materials. Carbon materials, particularly biomass charcoal, have attracted considerable attention due to their abundant availability and broad solar energy absorbing capacity. In addition, the evaporation mechanism of the interfacial solar driven desalination of sea water is similar to the transpiration of plants, and the root system supplies water to the leaves for evaporation just as the water conveyor conveys water to the photo-thermal material to generate steam. Many all-biomass based solar evaporators have been developed and can be divided into two types. The first type is a carbonized biomass-based solar evaporator that retains the natural pore structure of biomass for interfacial solar driven desalination of sea water, such as carbonized mushrooms and wood. Although this method can conveniently manufacture solar evaporators, carbonized biomass is susceptible to breakage due to moisture loss. The second type is a photothermal conversion film based on whole biowaste. Although the manufacture of photothermal films is relatively simple, its desalination performance may be affected by deposition of salt crystals on its surface during desalination. Based on the defects of the existing photo-thermal conversion materials based on biological wastes, improvement is needed. Disclosure of Invention In view of the above, the invention provides a photo-thermal conversion aerogel, and a preparation method and application thereof, so as to solve the defects in the prior art. In a first aspect, the present invention provides a method for preparing a photo-thermal conversion aerogel, comprising the steps of: Adding tea leaves residues into alkali liquor, reacting at 150-170 ℃, filtering, and washing to obtain tea leaves residues fibers; Calcining the tea residue fibers in a tube furnace at 500-700 ℃ to obtain carbonized tea residues; Grinding carbonized tea leaves into powder, adding the powder into acid liquor, soaking and washing to obtain tea leaves residue carbon powder; Adding sodium alginate into water, adding tea dreg fibers, adding tea dreg carbon powder, stirring, freezing and solidifying, and freeze-drying in a freeze dryer to obtain aerogel; and soaking the aerogel in CaCl 2 solution, washing, and freeze-drying in a freeze dryer to obtain the photo-thermal conversion aerogel. Preferably, in the preparation method of the photo-thermal conversion aerogel, the alkali solution comprises at least one of NaOH solution and KOH solution. Preferably, in the preparation method of the photo-thermal conversion aerogel, the concentration of the alkali liquor is 0.5-2 mol/L. The preparation method of the photo-thermal conversion aerogel is characterized in that tea residues are added into alkali liquor, react for 4-8 hours at 150-170 ℃, and are filtered and washed to be neutral to obtain tea residue fibers, wherein the mass volume ratio of the tea residues to the alkali liquor is (3-7) g (50-100) mL. Preferably, in the preparation method of the photo-thermal conversion aerogel, tea dreg fibers are placed in a tube furnace to be calcined at 500-700 ℃ for 1-3 hours. Preferably, in the preparation method of the photo-thermal conversion aerogel, carbonized tea leaves are ground into powder, the powder is added into acid liquor, the acid liquor is soaked for 1-3 hours and washed to be neutral, and tea leaves carbon powder is obtained, wherein the acid liquor comprises at least one of HCl solution, H 2SO4 solution and HNO 3 so