Fabrication Of Functional Fabric Via Radiation-induced Graft Polymerization For Catalytic Degradation Of Organic Pollutants

The removal of pollutants in water is important in modern industrial production and urban water cycle.In order to solve this problem,advanced oxidation?photocatalysis,photo-Fenton,and Fenton like?has been widely concerned with its unique advantages of simple operation,low cost and environmental friendliness.However,nanocatalysts are easy to agglomerate,difficult to recover and easy to be corroded,which greatly limits its large-scale application.To overcome the above shortcomings,loading nanocatalysts on macro-sized support is an effective strategy to improve the efficiency of nanocatalysts.Commercial fabric is one of the most attractive substrates because of its convenient manufacture,simple recyclability,stable reusability and easy surface modification.Radiation-induced graft polymerization?RIGP?was used to modify different fabrics to in situ immobilize the nanocatalysts in this work.Through the doping and modification of the grafted chain on the structure of nano-catalyst materials,the effects of anti-aging properties,photosensitivity,photocatalytic efficiency and photocatalyst stability of the composite materials were systematically investigated,and the mechanism of catalytic degradation was discussed.The purpose of this subject is to expand the application of RIGP and promote the rapid development of RIGP in emerging industrial field;this work will also enrich the relevant theories and technical prototype of flexible support in sewage treatment,and provide a new method for water purification.The main aspects are as follows:?1?Developing a universal strategy to improve the properties of polyethylene terephthalate?PET?fibers,such as UV resistance,hydrophobicity,and thermal resistance,is highly desirable in expanding the application of PET fibers.Herein,a highly durable and robust ZnO layer was deposited onto PET fabric via RIGP of?-methacryloxypropyl trimethoxysilane?MAPS?and the subsequent sol-gel in situ mineralization of ZnO?PET-g-PMAPS/ZnO?.The interfacial layer consisted of Zn-O-Si and Si-O-Si covalent bonds not only leads to an improvement in adhesion between ZnO nanoparticles and its support,but also overcomes the poor film-forming ability of inorganic particles.Photocatalytic self-degradation of its organic support caused by the high photocatalytic activity of ZnO can be eliminated because of high bond energy of the organic-inorganic hybrid structure.Superhydrophobicity was achieved by simply annealing the PET-g-PMAPS/ZnO fabric at 200?,and the coated fabric still retains its superhydrophobicity after 40 laundering cycles test and even stored for a few weeks.In addition,PET-g-PMAPS/ZnO exhibited excellent thermal resistance,UV resistance and durability.This study presents an effective method to overcome the bottle-necks in growing inorganic nanocrystals on polymeric supports surface.?2?A bifunctional interfacial layer was introduced onto the surface of cotton fabric which not only enhanced the interfacial bonding between Ag@ZnO and organic substrates but also improved the photocatalytic performance simultaneously.In detail,a modified cotton fabric?denoted as Cot-g-Si/Ag@ZnO?was fabricated through RIGP of MAPS and followed the in-situ formation of Ag@ZnO.Owing to Zn-O-Si between the graft chains and Ag@ZnO photocatalyst,the charge carrier concentration increased and Ag was prevented from oxidizing through the partial separation from ZnO,leading to enhanced the localized surface plasmon resonance.Cot-g-Si/Ag@ZnO also exhibited excellent photocorrosion resistance,photostability and laundering durability.Its photocatalytic activity was fully maintained after several photodegradation cycles;moreover,the photocatalytic activity was improved compared with the initial sample after laundering durability test.A mechanism for the photocatalytic activity of Cot-g-Si/Ag@ZnO under sunlight irradiation was proposed.?3?Industrial oily wastewater with refractory organic compound is a critical environmental issue for wastewater purification.However,the fabrication of effective and stable materials for oil-water separation and simultaneous degradation of organic contaminants remains a critical challenge.Herein,we report a new process for in-situ formation of akageneite??-FeOOH?nanorods layer on the surface of PET fabric via RIGP of glycidyl methacrylate and sulfonation.The resultant product is labeled as?-FeOOH@PET,which exhibits effective oil-water separation and organic dyes photodegradation under the illumination of visible light.It provides stable performance even after 1000 wash cycles.The sulfonated layer acts as not only an electronic transport layer to prevent electron-hole recombination,but also as an anchored interface for immobilizing?-FeOOH nanorods on the sulfonated layer via strong covalent bonds.Overall,?-FeOOH@PET fabric,along with its dual purification function,provides a new insight toward oil and organic pollutants wastewater remediation and purification in large-scale applications.?4?Advanced oxidation processes?AOPs?present one of the most promising strategies to deal with the ever-growing water pollution.However,fabricating catalysts with large size,long-term stability,and adequate activity is still a formidable challenge in practical applications.In this study,single cobalt atoms are covalently linked on the polypropylene nonwoven fabric?P-PFeCo?via RIGP and used as highly efficient and stable monoatom-like reaction sites to degrade high toxic and difficult biodegradable organics by activating peroxymonosulfate?PMS?.The presence of graft chains not only generates a well-defined monometallic reaction microenvironment,but also promotes electronic transfer.The prepared monoatomic catalyst has remarkable durability and recoverability with trace cobalt leaching.The X-ray absorption fine structure?XAFS?spectroscopy and density functional theory?DFT?calculations revealed that the single CoN₄?H₂O?₂ site acts as a monoatom-like active site for activating PMS.A device in a flow mode was also constructed to illustrate the potential applications of P-PFeCo.We consider that the monoatom-like catalytic process along with the large-sized substrate will broaden a new horizon in terms of designing high-performance catalysts for PMS activation in wastewater treatment.