Under Ultraviolet Irradiation Research Articles

Fabrication and Application of ZIF-8 Derived In2O3-ZnO Nanocomposites for Ultra-Sensitive NO2 Sensing under UV Irradiation at Room Temperature

Nitrogen oxide (NO2) is common by-products of industrial production, posing significant health risks to workers. Therefore, real-time monitoring of NO2 is crucial. In this study, innovative In2O3-ZnO nano-materials were prepared by combining In2O3 with ZIF-8 via electrospinning, for detecting trace amounts of NO2 at room temperature (RT). Compared to pure In2O3, the In2O3-ZnO nano-materials (V2) with a 10% weight ratio of ZIF-8 exhibited a significantly higher response (389.99) and a faster response time (16.9s) to NO2 under ultraviolet (UV) irradiation at RT. The superior gas sensing performance of the V2 nano-materials is attributed to the formation of n-n heterojunctions, enhanced optical absorption, increased oxygen vacancy ratio, and excellent dispersion among the nano-materials. The results demonstrate that V2 nano-materials can detect NO2 at parts-per-billion (ppb) levels at RT, making them suitable for monitoring trace amounts of NO2 in open environments. Furthermore, a portable real-time NO2 monitoring device was constructed using V2 as the sensing material, an LM358-based amplifier circuit for data acquisition, an STM32F103C8T6 microcontroller as the main control unit, and a buzzer as an alarm device. Compared to devices using a helical Ni-Cr wire as an indirect heat source, this integrated NO2 detection device offers real-time alarms with lower energy consumption. This application not only enhances worker health and safety in industrial environments but also demonstrates higher energy efficiency in practical application.

Deposition of modifiable MAO-PDA coatings on magnesium alloy based on photocatalytic effect

Micro arc oxidation-Polydopamine (MAO-PDA) composite coating is a functional corrosion resistant coating formed on the surface of magnesium alloy by combining MAO to form a porous ceramic layer and the spontaneous oxidation polymerization characteristics of PDA. The MAO-PDA coating is environmentally friendly and modifiable, providing a basic film layer for achieving self-warning, self-healing, conductivity and other modification functions, which has attracted widespread attention. A new type of MAO-PDA composite coating with good corrosion resistance was deposited on the surface of magnesium alloy by photocatalysis, which expanded the application range of magnesium alloy MAO surface treatment. Surface morphology, coating adhesion and corrosion resistance of the composite coating are characterized. Combined with Density functional theory (DFT) calculation, the possible mechanism is explored. The results indicate that the MAO layer containing Mg2TiO4 exhibits fewer pores and can better deposit PDA under ultraviolet (UV) light conditions, forming a magnesium alloy MAO-PDA composite coating with good corrosion resistance and modification friendliness. Band structure calculations confirm the photocatalytic effect of Mg2TiO4 under UV irradiation. As a result of the photocatalytic effect, reactive oxygen species (ROS) were generated in the pores and on the surface of the MAO sample, thus accelerating the local deposition of PDA.

Improvement of UV resistance and mechanism in polypropylene wax on wood surface through maleic anhydride and β-nucleating agent modification

In China, beeswax is commonly used to protect hardwood surfaces through hot waxing, and is widely utilized in wood furniture and buildings. However, beeswax, with its low melting point and high cost, is prone to being destroyed and falling off, and has a short-term protective effect on wood under ultraviolet (UV) light. Polypropylene wax (PPW), with its low cost and high melting point, holds potential for application in wood protection. The introduction of maleic anhydride enhanced the combination of PPW and wood, resulting in excellent surface properties. Additionally, the β-nucleating agent (WBG-II) induced PPW to form β crystal structure, further enhancing the UV barrier property of the wax coating. After UV irradiation, the surface properties of the hot-waxed wood using the modified polypropylene wax exhibited minimal changes, including color, adhesion, hydrophobicity, and surface roughness. The chemical structure, crystalline structure, and surface morphology were analyzed by FTIR, XRD, and SEM to reveal the photodegradation mechanism of the surface wax coating. The results demonstrated that the co-modification of polypropylene wax by maleic anhydride and WBG-II has a positive effect on the long-term protection of wood substrate, providing a reference for wood protection, particularly for dark and precious wood, and helping to reduce deforestation.

Sphere-shaped ZnO photocatalyst synthesis for enhanced degradation of the Quinolone antibiotic, Ofloxacin, under UV irradiation.

The sphere-shaped zinc oxide (ZnO) photocatalyst was synthesized by the homogeneous precipitation method, using Zn(CH3COO)2·2H2O as a zinc precursor and NH4OH as a precipitating agent. The morphology and crystal structure of the prepared ZnO sample were studied by XRD, SEM, FT-IR, XPS, zetapotential measurements, and a low-temperature nitrogen adsorption-desorption technique. The optical characteristics of ZnO were determined by UV - Vis diffuse reflectance spectroscopy. ZnO photocatalyst performance of up to 100% within 210min was observed in the photodegradation of the ofloxacin antibiotic under ultraviolet (UV) irradiation. The effect of antibiotic concentration, heavy metal ions, and water sources on the photocatalytic activity of ZnO demonstrated both the potential of its application under different conditions, and a good adaptability of this photocatalyst. The photodegradation reaction correlated well with the first-order kinetics model, with a rate constant of 0.0173min-1. The reusability of the photocatalyst was verified after three cycles of use. Admittedly, photogenerated electrons and holes played a key role in removal of the antibiotic. This work showed the suitability of prepared ZnO for antibiotic removal, and its potential use for environmental protection.

Synthesis and Assembly of Photoresponsive Colloidal Tubes.

Inspired by the sophisticated multicomponent and multistage assembly of proteins and their mixtures in living cells, this study rationally designs and fabricates photoresponsive colloidal tubes that can self-assemble and hybrid-assemble when mixed with colloidal spheres and rods. Time-resolved observation and computer simulation reveal that the assembly is driven by phoretic attraction originating from osmotic pressures. These pressures are induced by the chemical concentration gradients generated by the photochemical reaction caused by colloidal tubes in a H2O2 solution under ultraviolet (UV) irradiation. The assembled structure is dictated by the size and shape of the constituent colloids as well as the intensity of the UV irradiation. Additionally, the resulting assembly can undergo self-propelled motion originating from the broken symmetry of the surrounding concentration gradients. This motion can be steered by a magnetic field and used for microscale cargo delivery. The study demonstrates a facile synthesis method for colloidal tubes and highlights their unique potential for controlled, hierarchical self-assembly and hybrid-assembly.

Antifouling and smart covalent organic framework composite nanofiltration membranes with light-gated molecular transport

Covalent organic framework (COF) holds great promise in affording precise and fast molecular separation. Inspired by the light-gated channels in cell membranes, we developed artificial light-gated molecular channel composite membranes by vacuum filtration COF with azobenzene (AZO) functional groups. The simple stimuli response could remotely adjust the membranes separation performance. The cis membranes with off state under ultraviolet (UV) light have higher dye rejection than trans membranes with on-state channels. The permeance of composite membranes increased from 19.56 to ∼ 42.30 L h−1 m−2 bar−1, dye (Rose Bengal (RB)) rejection increased from 94.40 % to 99.12 % after 10 min of 365 nm UV irradiation. In addition, the composite nanofiltration membranes exhibited good antifouling performance due to hydrophilic and highly smooth surface. By controlling the trans-to-cis AZO isomerization via UV /visible (Vis) light, the solvent permeance and dye rejection can be dynamically tuned due to the adjustable pore size.

Triple passivation strategy for ultra-stable luminous CsPbBr3 NCs-Acrylate based films as backlight display

To improve the stability of CsPbBr3 nanocrystals (NCs), triple protection strategies were performed to obtain the ultra-stable films, including fluorinated hydrophobic film surface, polymer coating and silica encapsulation. CsPbBr3 QDs@SiO2 nanoparticles (SiPNCs) were prepared with well-dispersed NCs (8 nm) within acrylate-modified silica-shell. Polymer@SiPNCs (poly@SiPNCs) films were prepared by copolymerization of methyl methacrylate (MMA), 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl methacrylate (DFHM) and SiPNCs under ultraviolet (UV) light. Compared to CsPbBr3 NCs solution, SiPNCs solution had well maintained light absorption and emission wavelengths of ∼509 nm and ∼522 nm respectively. High SiPNCs content resulted in enhanced micro/nano structure and increased roughness on the surface of poly@SiPNCs film. With increasing SiPNCs content, water contact angles (WCAs) of poly@SiPNCs films reached 126 ± 2.4°, 137.3 ± 1.3° and 141.5 ± 1.9° respectively. This fabricated poly@SiPNCs film exhibited much improved stabilities to water and UV light, even after 90 days of water immersion and 120 h of UV irradiation. White light-emitting-diode (LED) device emitted bright pure white light. This work will boost a large-scale preparation of stable QDs films as backlight display.

Fluorinated TiO2 Hollow Spheres for Detecting Formaldehyde under UV Irradiation.

The fluorinated titanium dioxide (F-TiO2) hollow spheres with varying F to Ti molar ratios were prepared by a simple one-step hydrothermal method followed by thermal processing. The diameter of the F-TiO2-0.3 hollow spheres with a nominal ratio of F:Ti = 0.3:1 was about 200-400 nm. Compared with the sensor based on pristine TiO2 sensing materials, the F-TiO2-0.3 sensor displayed an enhanced sensing performance toward gaseous formaldehyde (HCHO) vapor at room temperature under ultraviolet (UV) light irradiation. The F-TiO2-0.3 sensor demonstrated an approximately 18-fold enhanced response (1.56) compared to the pristine TiO2 sensor (0.085). The response and recovery times of the F-TiO2-0.3 sensor to 10 ppm HCHO were about 56 s and 64 s, respectively, and a limit-of-detection value of 0.5 ppm HCHO was estimated. The F-TiO2-0.3 sensor also demonstrated good repeatability and selectivity to HCHO gas under UV light irradiation. The outstanding HCHO gas-sensing properties of the F-TiO2-0.3 sensor were related to the following factors: the excitation effect caused by the UV light facilitated surface chemical reactions with analyte gas species; the hollow sphere structure provided sufficient active sites; and the surface fluoride (≡Ti-F) created additional chemisorption sites on the surface of the TiO2 material.

Self-Cleaning Highly Porous TiO2 Coating Designed by Swelling-Assisted Sequential Infiltration Synthesis (SIS) of a Block Copolymer Template.

Photocatalytic self-cleaning coatings with a high surface area are important for a wide range of applications, including optical coatings, solar panels, mirrors, etc. Here, we designed a highly porous TiO2 coating with photoinduced self-cleaning characteristics and very high hydrophilicity. This was achieved using the swelling-assisted sequential infiltration synthesis (SIS) of a block copolymer (BCP) template, which was followed by polymer removal via oxidative thermal annealing. The quartz crystal microbalance (QCM) was employed to optimize the infiltration process by estimating the mass of material infiltrated into the polymer template as a function of the number of SIS cycles. This adopted swelling-assisted SIS approach resulted in a smooth uniform TiO2 film with an interconnected network of pores. The synthesized film exhibited good crystallinity in the anatase phase. The resulting nanoporous TiO2 coatings were tested for their functional characteristics. Exposure to UV irradiation for 1 h induced an improvement in the hydrophilicity of coatings with wetting angle reducing to unmeasurable values upon contact with water droplets. Furthermore, their self-cleaning characteristics were tested by measuring the photocatalytic degradation of methylene blue (MB). The synthesized porous TiO2 nanostructures displayed promising photocatalytic activity, demonstrating the degradation of approximately 92% of MB after 180 min under ultraviolet (UV) light irradiation. Thus, the level of performance was comparable to the photoactivity of commercial anatase TiO2 nanoparticles of the same quantity. Our results highlight a new robust approach for designing hydrophilic self-cleaning coatings with controlled porosity and composition.

Photo-induced grease/oil switched lubricant for friction regulation

Controllable friction regulation has drawn much interest in both scientific and industrial fields. And there have been many researches on friction regulation by many physical fields and chemical factors. Photo-sensitive materials are promising because it is relatively easy to change their properties compared with others. Here, a new kind of photo-induced grease/oil switched lubricant is designed and shows great reversibility under ultraviolet (UV) and visible (Vis) irradiation. Its viscosity can change more than 50 times under different irradiation, and the coefficients of friction (COFs) obviously increase under Vis irradiation and decrease under UV irradiation, which performs better than those of the common grease. According to the experimental results, the phenomena are contributed to the break and reconstruction of the three-dimensional network inside the lubricant. With a switchable grease/oil state under different irradiation, this work provides a new principle for designing a smart lubricant with controllable friction regulation.

Pauling-type adsorption of O2 induced reactive oxide species in photocatalytic oxidation by TiOx sensitized Pb-hyperaccumulated biochar

A novel TiOx-loaded Pb-hyperaccumulated biochar (Pb@BC-TiOx) was obtained from the hyperaccumulator Iris siberian L. Compared with other metal@BC-TiO2 (Ce, Co, Ni, Fe), Pb@BC-TiOx showed a stronger potential for pollutant degradation under ultraviolet (UV) irradiation, achieving 97.9 % of 2,4-dichlorophenol (2,4-DCP) removal within 240 min. Quenching experiments exhibited the selective enhancement of superoxide radicals (·O2-) and singlet oxygen (1O2) in the Pb@BC-TiOx/UV system (5.6 and 7.9 times than Pb@BC/UV system, respectively). The characterization revealed TiOx and PbO2 in the Pb@BC-TiOx, and the photogenerated electrons (e-) and holes (h+) flowed between them. In TiOx, TiO1.04 was formed due to the reductive effects of CO and/or Pb0. Moreover, the heterojunction schemes of TiO1.04 and TiO2 also exhibited a superior photogenerated e- transfer capability. Density functional theory calculations showed that TiO1.04 on the surface of Pb@BC-TiOx induced Pauling-type adsorption of O2, which reduced the overall activation energy barrier (-1.76 eV), facilitated the maintenance of O-O bonds and the accumulation of ·OOH, and futher promoted the generation of ·O2-/1O2 instead of H2O under UV irradiation. The Pb@BC-TiOx/UV system exhibited superior reusability and applicability, which was beneficial to practical wastewater treatments. This study provided a novel idea for the preparation of catalysts using metal-hyperaccumulated biomass produced after phytoremediation.

Poly(vinyl alcohol)-tragacanth gum/Titania bio-nanocomposite film for photodecomposition of malachite green

Concerned about the contamination as a consequence of untreated wastewater worldwide, nanomaterials have been utilized for purification. Nevertheless, their separation from water is difficult after the treatment. Herein, Titania nanomaterials were embedded in a poly(vinyl alcohol)-tragacanth gum (PVA-TG) matrix, due to easy separation. The polymer matrix was cross-linked by a green agent of citric acid, and the physicochemical properties of PVA-TG/Titania bio-nanocomposite (bio-NC) films were characterized, which displayed a high swelling ratio in the water because of the addition of TG. Further, Titania nanomaterials illustrated a cube-like shape in the PVA-TG/Titania bio-NC film confirming the complete dispersion. Afterward, the photodecomposition of malachite green (MG) over this bio-NC film was studied and optimized under ultraviolet (UV) irradiation. Scavenger agents determined that the electron was produced more than other radical agents. Ultimately, the photodegradation process of MG over bio-NC films was suggested by the hydroxyl addition, singlet oxygen, and UV irradiation transformation pathways.

Rhombohedral boron monosulfide as a metal-free photocatalyst

Most of previous photocatalysts contain metal species, thus exploring a metal-free photocatalyst is still challenging. A metal-free photocatalyst has an advantage for the development of economical and non-toxic artificial photosynthesis system and/or environmental purification applications. In this study, rhombohedral boron monosulfide (r-BS) was synthesized by a high-pressure solid-state reaction, and its photocatalytic properties were investigated. r-BS absorbed visible light, and its photocurrent action spectrum also exhibited visible light responsivity. The r-BS evolved hydrogen (H2) from water under ultraviolet (UV) as well as under visible light irradiation, and its internal quantum efficiency reached 1.8% under UV light irradiation. In addition to the H2 evolution reaction, the r-BS photocatalyst drove carbon dioxide (CO2) reduction and dye oxidation reactions under UV irradiation. Although bare r-BS was not so stable under strong light irradiation in water, cocatalyst modification improved its stability. These results indicate that r-BS is a new class of non-metal photocatalyst applicable for H2 production, CO2 reduction, and environmental purification reactions.

Photocatalytic effect of N–TiO2 conjugated with folic acid against biofilm-forming resistant bacteria

Antibiotic resistance challenges the treatment of bacterial biofilm-related infections, but the use of nanoparticles as a treatment is a promising strategy to overcome bacterial infections. This study applied nitrogen-doped titanium dioxide (N–TiO2) conjugated with folic acid (FA) on biofilm-forming resistant bacteria. The photocatalytic effect of TiO2 nanoparticles (NPs) was studied under ultraviolet (UV), visible light, and dark conditions at 60, 120, and 180 min against planktonic cells and biofilms of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa. TiO2 NPs were in the anatase phase, spherical shaped with sizes of 10-13 nm, and effectively doped and conjugated with N and FA. The FA-conjugated nanoparticles (N–TiO2-FA and FA-TiO2) were shown to have a bactericidal effect on all bacteria between 60 and 180 min under UV and visible light conditions. Concerning biofilms, N–TiO2-FA was shown to have a highly disruptive effect on all bacterial biofilms under UV irradiation at 180 min. Meanwhile, the nanoparticles did not show DNA damaging potential and they had no cytostatic effect, indicating that these NPs are biocompatible. In sum, nanoparticle conjugation with FA promoted photocatalytic effectiveness, revealing the promise this nanomaterial holds as a biocompatible antimicrobial agent.

Ultraviolet-light–dark cycle analysis of degradation in perovskite solar cells

The stability of perovskite solar cells must be evaluated under realistic outdoor conditions, such as light–dark cycles, because their reversible performance changes under such conditions. Therefore, in this study, we performed light–dark cycle analysis of lead halide perovskite solar cells under ultraviolet (UV) light irradiation to evaluate their metastability and UV degradation. The power drop under UV irradiation was recovered after storing the cells in dark because of ion-migration effects. Furthermore, the energy yield during 6 h of UV irradiation reduced slightly during the light–dark cycles, similar to the reduction in energy yield observed under a white-light-light-emitting diode. This change in energy yield indicates that the power drop observed after 6 h of UV irradiation cannot be attributed to UV-induced degradation of the perovskite used in this study. Our findings show that light–dark cycle analyses are effective for distinguishing between metastability and UV-induced material degradation.

Tetrahydrobiopterin as a Trigger for Vitiligo: Phototransformation during UV Irradiation.

Vitiligo is a type of hypomelanosis. Tetrahydrobiopterin (H4Bip), the coenzyme of the initial stage of melanogenesis, appears to be a trigger for vitiligo. H4Bip is present in vitiligo in 3-5-fold excess and causes oxidative stress by triggering an autocatalytic cycle of excess hydrogen peroxide synthesis. Using quantum-chemical calculations, we have evaluated the possibility of H4Bip reactions occurring in the dark and under ultraviolet (UV) irradiation, including the formation of dihydropterin dimers. In order to simulate the oxidative stress, oxidative modification of human serum albumin (HSA) has been carried out in the presence of excessive H4Bip using the fluorescence method. The fraction of oxidized protein (FOP) has been calculated. It has been established that there is a strong oxidative modification of amino acids chromophores (tryptophan and tyrosine) in the protein (FOP 0.64). Under UV irradiation of the system (HSA + H4Bip), FOP is reduced to 0.39. Apparently, a part of H4Bip transforms into dihydropterin dimers and does not participate in the oxidative modification of the protein. The data on oxidative modification of HSA are consistent with dynamic light scattering: H4Bip promotes HSA aggregation with the formation of particles with a hydrodynamic radius Rh ≥ 2000 nm, which can become immunogenic.

A non-fluorinated superhydrophobic PDMS/STA/TiO2 coating with photocatalysis and environmental stability properties by one-step cold spraying

Constructing a titanium dioxide (TiO2) superhydrophobic surface that is both environmentally friendly and long-term stable, while also possessing photocatalytic properties, is a considerable challenge. In this work, instead of a perfluorinated modifier, we used stearic acid (STA) to modify TiO2 nanoparticles. The particles were further utilized to facilitate the rough structure of superhydrophobic surfaces, making these surfaces fluoride-free and environmentally friendly in practical applications. STA/TiO2 nanoparticles and Polydimethylsiloxane (PDMS) were mixed in an ethyl acetate solution to form the PDMS/STA/TiO2 emulsion, which was used to prepare the PDMS/STA/TiO2 coating by a one-step cold spraying. PDMS was introduced into the coating, providing the lower surface energy, adhesiveness, and protection from photo-oxidative damage. It is found that the non-fluorinated PDMS/STA/TiO2 coating exhibits good superhydrophobicity with a water contact angle of 159.7° and a sliding angle of 2.9°. Under ultraviolet (UV) irradiation, the coating displayed excellent photocatalytic degradation activity towards Methylene Blue, Methyl Orange, and Nile Red dyes. Moreover, the coating can withstand sandpaper abrasion, high temperatures and exposure to droplets of different pH values, indicating good chemical, mechanical and thermal stability. The coating presented strong durability, maintaining its superhydrophobicity even after being exposed to air for 3 months or UV irradiation for 5 h. Besides, the coating demonstrates good self-cleaning performance and adaptability. The large-area superhydrophobic surface made by simple and convenient one-step cold spraying is expected to have practical applications in shipbuilding, construction, textiles, and other industries.

Effect of copper and silver as a middle layer on the structural, electrical, photocatalytic, and optical properties of ZnS/metal/ZnS films for optoelectronics applications

In this work, we utilized the thermal vacuum evaporation technique to fabricate ZnS single-layer thin films, ZnS/Cu/ZnS (ZCZ), and ZnS/Ag/ZnS (ZAZ) multilayer thin films. The influence of the middle layer of metals like copper and silver on the physical properties of ZnS/metal/ZnS multilayers is investigated. The results of the X-ray investigation demonstrate that the samples are polycrystalline, with a cubic ZnS structure and texture (111) at 2 = 29.1°. The optical investigation using Tauc’s approach yields energy gap values of 3.76 eV, 3.68 eV, and 3.6 eV for ZnS, ZCZ, and ZAZ films, respectively. CO2 gas sensing efficiency of ZnS, ZCZ, and ZAZ films were found to be at different operating temperatures. The optimal temperatures for ZnS, ZCZ, and ZAZ thin films were determined to be 483 K, 693 K, and 693 K, respectively. Under ultraviolet (UV) irradiation, the photocatalytic activity of ZnS, ZCZ, and ZAZ films for the degradation of methylene blue were studied. The results suggest that the metal intermediate layer is significant in improving the photocatalytic capabilities of ZnS films. When compared to ZnS single layer film (degradation efficiency of 15% after 180 min of UV irradiation), ZAZ multilayer film demonstrates the highest photocatalytic activity (degradation efficiency of 50% after 180 min of UV irradiation). The mechanism of the metal middle layer’s improved UV photoactivity is briefly discussed.

Analyzing Deformation of a Cationic Photopolymerized Epoxy Adhesive during the Curing Process in UV Irradiation and Dark Reaction based on Finite Element Method and Measurement

ABSTRACT In the manufacturing of optical products, precise adjustments are made to maintain the optical axis alignment of optical components, which are then securely positioned using adhesives. To achieve positional accuracy at the micron level, it is essential to comprehend the deformation of the adhesive joint over time during processing. This study focuses on investigating the displacement of optical components resulting from the deformation of a cationic photopolymerized epoxy adhesive, which cures under ultraviolet (UV) radiation. First, the conversion of the adhesive was formulated based on a curing reaction model. This conversion can be divided into three stages: the initial reaction during UV irradiation, the subsequent dark reaction, and the reaction induced by heating. Moreover, formulations were developed to describe changes in curing shrinkage, thermal expansion, and viscoelasticity in relation to the conversion. These equations, governing the adhesive properties, were then used to perform finite element method (FEM) simulations to analyze the position of the optical component. Experimental tests on adhesively bonded components were conducted under conditions identical to those employed in the simulation. Throughout the curing process of the adhesive, the optical component was continuously imaged using a coherence-scanning interferometer, enabling the quantification of its displacement from the acquired images. The results of the FEM simulation and experimental analysis exhibited a consistent trend, indicating the effectiveness of the modeling and simulation methods employed in this study. The majority of the displacement of the optical component occurred over several hours during the dark reaction stage, rather than during UV irradiation. Notably, the movement of the optical component was not limited solely to the thickness direction of the adhesive layer because of curing shrinkage but also extends to the in-plane direction because of the non-uniform distribution of the UV irradiation intensity.

Investigation of Bleaching of Cotton Fabrics with UV-TiO2

Titanium dioxide exhibits photocatalytic properties under ultraviolet (UV) irradiation. In this study, an environmentally friendly, fast and efficient technique for bleaching cotton fabrics is presented, utilising the photocatalytic property of TiO2. Raw cotton fabric samples were treated with TiO2-containing and TiO2-free treatment solutions (hydrogen peroxide and sodium hydroxide) under UV irradiation in order to bleach the samples. The results showed that cotton fabrics treated with TiO2 were bleached satisfactorily without severe strength loss.