Copyright © 2022 Foshan MBRT Nanofiberlabs Technology Co., Ltd All rights reserved.Site Map
In recent years, water pollution has become increasingly serious due to the rapid growth of population and the development of manufacturing and agriculture. Dyes are widely used in the textile industry. Methylene blue (MB), rhodamine B (RhB) and methylene orange (MO) are common dyes. MB is an aromatic heterocyclic cationic dye, RhB is a synthetic cationic dye, and MO is an anionic dye. However, the production and use of dyes will produce a large amount of dye wastewater, which will cause serious pollution to the water environment if it is directly discharged into the water without treatment. In addition, due to the widespread use and even abuse of antibiotics in animals, antibiotics will flow into the water through livestock and poultry manure, posing a threat to humans. Antibiotics are generally divided into macrolides (such as EM), fluoroquinolones (such as CIP), tetracyclines (such as TC) and sulfonamides (such as SMX). In summary, organic dyes, antibiotics and pathogenic microorganisms are the main water pollutants, which are highly carcinogenic and toxic.
The main point of this paper
Photocatalytic degradation technology:
Photocatalytic degradation is considered to be a green and effective technology with important applications in wastewater treatment. It has excellent photocatalytic degradation performance for organic dyes and antibiotics
Challenges of commercial TiO2 (P25):
Commercial P25 as a powdered photocatalyst is easy to aggregate and inconvenient to recover from the solution, resulting in easy loss and unfavorable recycling application
Application of electrospinning technology:
Electrospinning technology can charge polymer droplets under high voltage to form polymer nanofibers. This technology can prepare composite fiber membranes with uniformly dispersed nanoparticles, which helps to solve the aggregation and recyclability problems of P25 nanoparticles
Combination of TiO2 with different carriers:
Some studies have combined TiO2 with different carriers such as natural wood, cellulose fibers, and cellulose nanocrystals to improve their photocatalytic performance and recyclability
Utilization of straw resources:
Straw, as an annually renewable agricultural waste, can be used as a raw material for the production of cellulose acetate (CA), used to prepare electrospun CA fiber membranes, and as a dispersed substrate for P25 nanoparticles
Electrospinning-electrospray (EE) method:
This study proposed a new and simple electrospinning-electrospray (EE) method to anchor P25 nanoparticles on the surface of straw-derived CA nanofibers and successfully prepared a series of EE-CA/P25 nanofiber membranes
Performance of EE-CA/P25 nanofiber membranes:
The photocatalytic degradation performance of EE-CA/P25 nanofiber membranes on different dyes and antibiotics was systematically studied, showing excellent photocatalytic degradation efficiency. In addition, the photocatalytic bactericidal performance of the membrane against Escherichia coli has also been verified
Innovative technology:
The study proposed an electrospinning-electrospray (EE) technology for anchoring TiO2 (P25) nanoparticles on cellulose acetate (CA) nanofibers.
Material characterization:
The EE-CA/P25 nanofiber membrane was fully characterized by SEM, TEM, FI-IR, XRD, DRS, PL, UV-vis and 3D-EMMs.
Photocatalytic performance:
The EE-CA/P25 nanofiber membrane has a very high photocatalytic degradation efficiency for organic dyes (MB), reaching 99.13% within 30 minutes.
It also shows good photocatalytic degradation efficiency for antibiotics (TC, CIP, SMX), especially for TC, which reaches 83.59%.
Antibacterial effect:
The antibacterial efficiency against Escherichia coli is as high as 98.42%, and it still maintains an efficiency of 97.49% after 5 cycles of use.
Reaction mechanism:
Active free radical capture experiments revealed that h+, •O2− and •OH participated in the photocatalytic reaction, among which h+ and •O2− played the main role.
Environmental protection and recyclability:
EE-CA/P25 nanofiber membrane is easy to recycle, which is conducive to environmental protection and resource recycling
In summary, a series of EE-CA/P25 nanofibrous membranes were prepared by electrospinning-electrospinning method. The E-CA/P25 nanofibrous membranes were prepared by conventional electrospinning method for comparison. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results showed that in EE-CA/P25 nanofibers, P25 nanoparticles were anchored on the surface of CA nanofibers, but most of the P25 nanoparticles were wrapped in CA nanofibers, and only a small amount of P25 nanoparticles were exposed in the E-CA/P25 nanofibrous membrane (0.05). In terms of obtaining more exposed P25 nanoparticles, the electrospinning-electrospinning method has a more significant advantage than the electrospinning method. The photocatalytic performance of EE-CA/P25 (0.05) nanofibrous membrane is better than that of E-CA/P25 (0.05). Taking MB, RhB and MO as simulated pollution sources, EE-CA/P25 (0.05) nanofiber membrane has the highest photocatalytic degradation efficiency for MB dye, reaching 99.13% after 30 min of illumination. For different antibiotics TC, CIP and SMX, EE-CA/P25 (0.05) has the best photocatalytic degradation effect on TC after 30 min of illumination, reaching 83.59%. The antibacterial efficiency of EE-CA/P25 (0.05) against Escherichia coli is 98.42%. In summary, EE-CA/P25 (0.05) nanofiber membrane may be a promising and efficient photocatalyst for the degradation and antibacterial of organic pollutants in the industrial field. In short, this study proves the high-value utilization of straw waste and expands the application of straw in the field of photocatalysts.
