Electrospinning Preparation Of Nano-gold Composite Material And Its Application In Formaldehyde Purification

Formaldehyde is one of the most common indoor volatile organic pollutants.Efficient formaldehyde elimination technology has been widely concerned.In addition to the traditional physical adsorption method and chemical reaction method,the chemical catalytic oxidation method only contains carbon dioxide and water in the final product of formaldehyde degradation,which can effectively remove formaldehyde in a short time.It was found that the noble metal nanocatalysts with the size below 10 nm had excellent lowtemperature oxidation activity.The aggregation effect makes the selection of supports particularly important.The nanofiber membrane prepared by electrospinning technology has both high gas flux and dense fiber network structure,so that the gas has enough residence time and can fully contact with the supported catalyst.In addition,the electrospun fiber as a catalyst support can also produce a strong synergistic effect with the catalyst and enhance the catalytic efficiency.In this work,by electrospinning,the soluble polymer microspheres loaded with nanogold particles were mixed with the spinning solution,and then the polymer template was dissolved and removed to prepare a porous electrospinning fiber membrane with nano gold catalyst,and its catalytic oxidation of formaldehyde was studied.(1)Determination of parameters of the electrospun fiber membrane.The effects of different solvents and additives on electrospinning were studied.It was found that propyl formate and isobutyl acetate as solvents and solid phosphate ionic liquid as additive were the best choice,so as to obtain the fiber membrane with fine diameter and appropriate strength.N-hexylpyridine hexafluorophosphate[HPy][PF6] was added to PVB/propyl formate and PVB/isobutyl acetate solutions respectively,the properties of spinning solution,morphology of fibers and electrospinning process were studied in detail.(2)Preparation of nano-gold catalyst.The soluble PMAA microspheres were prepared by distillation-precipitation polymerization.Then,gold nanoparticles(Au-PMAA)loaded on the surface of microspheres were prepared by in-situ reduction method,using the acetone chloroaurate solution as the gold source and PMAA as the support.The effects of parameters such as the amount of reducing agent,support,and reaction medium on the properties of gold nanoparticles were studied in detail.(3)Preparation of gold nanoparticle composite porous nanofiber membrane and its application in formaldehyde purification.Au-PMAA was mixed with spinning fluid to prepare composite nanofiber membrane under the optimal spinning conditions.Then,the PMAA template was dissolved and removed by the solution of sodium hydroxide with p H=10 to obtain the gold nanoparticle composite porous nanofiber membrane.This porous structure can make the gold nanoparticles partially stable on the inner wall of the hole,avoiding the disadvantage that the nanocatalysts are completely wrapped in the fiber when the metal nanoparticles and the spinning solution are directly blended and spun.The supported catalyst fiber membrane was used to remove formaldehyde,and the purification effect reached the best when the catalyst load was 1wt% at room temperature.