UV Irradiation Time Research Articles

Degradation of N-Nitrosodiethylamine in aqueous solution by gamma-irradiation

ABSTRACT N-Nitrosodiethylamine (NNDEA) is a toxic compound which is affranchised into the medium mostly via industrial wastewater. For the investigation of degradation mechanism of NNDEA, the aqueous solutions of NNDEA were exposed to Advanced Oxidation processes (AOP’s) such as gamma-irradiation, ozonation, UV irradiation and UV/Ozone (ozone effect) and UV/H2O2 (hydrogen peroxide effect). Since the structure of NNDEA is small, it is rapidly degraded in all processes except UV-irradiation process but forming acetic acid and formic acid just was seen in gamma and UV/H2O2processes. In the other processes, NNDEA is transformed directly to nitrite and nitrate which they can form NNDEA again in the medium. The concentration of NNDEA was decreased from 50 to 21 mg L−1 after 2.20 kGy gamma-irradiation. After 2.85 kGy gamma irradiation, NNDEA was completely removed from the medium. The results showed that the concentration of NNDEA decreased with UV-irradiation time, the concentration of 50 mg L−1 NNDEA was 42, 30, 24 and 19 mg L−1 after 10, 20, 40 and 60 min UV-irradiation, respectively. It has been investigated that the UV-irradiation does not have much effect on the degradation of 50 mg L−1 NNDEA solution and requires long-term irradiation. In this study, gamma-irradiation was chosen as the best method because of the complete degradation effect and the prevention of the reformation of the NNDEA.

Experimental study on photocatalytic degradation efficiency of mixed crystal nano-TiO2 concrete

Abstract The photocatalytic mixed crystal nano-TiO2 particles were incorporated with concrete by means of the internal doping method (IDM) and spraying method (SPM) in this paper. To evaluate the photocatalytic degradation efficiency of mixed crystal nano-TiO2 concrete, the methyl orange (MO) was chosen to simulate pollutants. The physicochemical characteristics and photocatalytic performance of mixed crystal nano-TiO2 concrete prepared by above two different methods were experimentally investigated under UV irradiation and solar irradiation. Furthermore, the effects of two key influential factors including pollutant concentration and irradiation condition were also analyzed and discussed. Experimental results indicate that the nano-TiO2 concrete prepared by the spraying method (SPM) exhibits maximum photocatalytic degradation efficiency of 73.82% when the sprayed nano-TiO2 slurry concentration is 10mg/L. The photocatalytic degradation efficiency of unpolished nano-TiO2 concrete is much higher than that of polished nano-TiO2 concrete under the same exposure time of UV irradiation. Moreover, the photocatalytic degradation efficiency of nano-TiO2 concrete decreases with the increase of pollutant concentration. The irradiation condition has an obvious influence on the photocatalytic degradation efficiency of nano-TiO2 concrete. In the aspect of applications, the practical recommendations for the nano-TiO2 concrete with self-cleaning capacity were presented according to the experimental results.

Albumin/Ag Nanoparticles Synthesized by Using UV-Irradiation and Estimation of Their Antibacterial Activity

Nano-scale (less than 100 nm) materials have received wide attention because of their rare properties that differ significantly from a bulk sample of the same material. In this research, a physical irradiation method by using UV lamp was established for preparation nanoparticles colloids of silver nanoparticles (Ag-NPs) with an eco-friendly stabilizer (Albumin). The preparation process was carried out using silver nitrate (AgNO3) in aqueous albumin at room temperature. The effects of UV-irradiation time and the concentrations of Ag+ and albumin on the particle size have been investigated. Moreover, the antibacterial effect of the Ag/Albumin nanoparticles has been tested. The results showed that, the UV–irradiation can influence the Ag-NPs size, which the of Nps decreases with the UV–irradiation increases. The morphological study demonstrated well-dispersed spherical Ag-NPs with an average diameter of about 29 nm at the optimum conditions. The antibacterial results exhibited a significant inhibitory effect for the Ag-NPs that synthesized in this work. The current fabrication method of the silver nanoparticles colloid could be extended to other metals such as Cu- Nps and may possibly find various additional applications.

SiO2 Coated on ZnO Nanorod Arrays With UV-Durable Superhydrophobicity and Highly Transmittance on Glass.

ZnO nanorod arrays were fabricated on glass through hydrothermal way. Then a thin SiO2 film was covered on ZnO nanorod arrays using pulsed laser deposition (PLD) technique, and modified by stearic acid. It was found that SiO2 film only had slight effects on the contact angle and transmittance of ZnO nanorod arrays. However, it had brought a huge improvement in the UV durability of superhydrophobic ZnO nanorod arrays. The results showed that the water contact angle remains constantly at 160.5° even UV irradiation time exceeded 50 h when the deposition time of PLD was about 10 min. This structure with UV-durable superhydrophobicity and highly transmittance on glass substrate can be served as front materials in solar cells.

Micromechanics analysis of carbon fiber/epoxy microdroplet composite under UV light irradiation by micro‐Raman spectroscopy

AbstractEvaluation of the surface morphology, chemical groups, interfacial microstructure, and mechanical properties of carbon fiber/epoxy resin microdroplet composites during ultraviolet photodegradation was carried out. The axial stress distribution and interfacial shear stress (ISS) distribution of the carbon fiber/microdroplet composite at 0.25% and 0.62% strains with different UV irradiation times were obtained using micro‐Raman spectroscopy. The results showed that after 40 hours of UV irradiation, tiny particles appeared on the surface of the carbon fiber/microdroplet sample, and with prolonged irradiation, the tiny particles grew larger and more in number. Benzyl methyl ketone was observed after 40 hours of UV irradiation, and the formation of the quinone methide structure, which causes the discoloration of composite, appeared after 300 hours of UV irradiation, and the tiny particles formed on the composite might be benzyl methyl ketone. The maximum axial stress reduced to 53% and 37%, and maximum shear stress reduced to 67% and 66%, for the 0.25% and 0.62% strain samples, respectively, when the UV irradiation time was extended to 940 hours. A power‐law function of ISS with irradiation times was proposed and is represented by τ0.25 = 66.78 ‑ 8.296 × 10–6 t2.26 and τ0.62 = 81.24 ‑ 2.20 × 10–6 t2.49. It was further determined that the loss of mechanical properties was slow during the first 300 hours of UV irradiation. This work provides a new approach for studying the influence of UV irradiation on the interfacial properties of fiber/polymer composite.

Photocurable bulk epoxy resins based on resorcinol derivative through cationic polymerization

AbstractBio‐sourced epoxy resins from resorcinol diglycidyl ether (RDGE) have been obtained by using cationic photopolymerization under UV‐light exposure. The photoinduced bulk resin samples were characterized by three‐point bending tests, dynamic mechanical analysis, as well as differential scanning calorimetry analysis, and thermogravimetric analysis. The influence of processing parameters, that is, reactant contents, UV irradiation time, and postcuring conditions on the thermomechanical behavior has been pointed out. For instance, the flexural modulus of the most performing materials reaches 4.1 GPa with the flexural strength and the glass‐transition temperature of around 105 MPa and 99°C, respectively. Interestingly, our optimized protocol has led to the synthesis of new bio‐based materials with more valuable thermal and mechanical properties than those of thermocured materials obtained from petroleum‐based commercial epoxy resins. Focus has been given on processing parameters to optimize the final properties of the material and to open an interesting alternative for sustainable building materials.

Degradation product distribution of Reactive Red-147 dye treated by UV/H2O2/TiO2 advanced oxidation process

The presence of dyes in industrial effluents is of public health concern. A considerable attention was paid to remove the dyes from the aquatic environment. This study focusses on the degradation of reactive red (RR-147) dye under UV irradiation in the presence of hydrogen peroxide (H2O2) and nano photo catalyst (TiO2). Effect of different parameters like dye concentration, pH, H2O2, UV irradiation time and TiO2 was studied. The maximum degradation of 92% for 50 ppm dye concentration, pH 3.4, H2O2 0.9 mL, TiO2 0.6 g and UV irradiation time 60 min was observed. The UV/Vis spectrophotometer was used to investigate the change in absorbance after UV irradiation. The 57 % reduction in COD was achieved when the dye aqueous solution was exposed to UV/H2O2/TiO2 process under optimized conditions. The FTIR was used for the identification of degraded product after UV irradiation treatment. The FTIR study showed that most of the functional group peaks were disappeared after the UV/H2O2/TiO2 treatment. LCMS/GCMS analyses scrutinized the intermediates and a mechanistic degradation pathway has also been proposed. The cytotoxicity of the irradiated dye samples was assessed using hemolytic test while mutagenic evaluation was carried out using the Ames test before and after treatment. The UV/H2O2/TiO2 is proved to be more capable and efficient system for the degradation of the RR-147 dye as compared to UV/H2O2 alone.

Optimization and evaluation of the efficiency of sono-Fenton and photo-Fenton processes in the removal of 2, 4, 6 trinitrotoluene (TNT) from aqueous solutions

The adverse health effects of trinitrotoluene (TNT) include allergies, liver and blood damage, and carcinogenesis. The present study aimed to optimize the sono-Fenton and photo-Fenton processes for the removal of TNT from aqueous solutions. TNT removal was evaluated at various pH (acidic, neutral, and alkaline), pollutant concentrations (10, 30, 50, 100, and 120 mg/l), H2O2 concentration (10-80 mM), and ferrous ions (0.5-4 Mm). After the optimization of the parameters, the appropriate UV irradiation time and optimal time of ultrasonic waves were determined for the removal of this compound. TNT concentration was measured using high-performance liquid chromatography. Increased hydrogen peroxide from 10 to 40 mMole/l led to higher TNT degradation (45.3% to 88.4% and 40 to 80 mMole/l), while the removal rate decreased from 88.4% to 79%. At the optimal H2O2 concentration, increased pH (3±0.2 to 11±0.2) decreased TNT decomposition from 88.4% to 23.5%. In addition, increased time (5 to 60 minutes) led to the higher photo-Fenton process efficiency (68.6% to 89%). The maximum photo-Fenton efficiency was achieved in optimal conditions at the TNT concentration of 10 mg/L (97%) and 60 minutes, while the efficiency of the sono-Fenton process in optimal conditions was 100% at 20 minutes. Therefore, it was concluded that the sono-Fenton process was effective in the removal of TNT.

Polymer brushes prepared by surface-initiated atom transfer radical polymerization of poly (N-isopropyl acrylamide) and their antifouling properties

Poly (N-isopropyl acrylamide) (PNIPAAm) polymer as a thermo-responsive coating was synthesized by surface-initiated atom transfer radical polymerization (SI-ATRP) on glass substrates. The effects of chain grafting density and polymerization time on the fouling release behavior of a marine diatom were investigated. The PNIPAAm grafting and its thermo-responsiveness were confirmed by different analyses such as scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), energy-dispersive X-ray spectroscopy, and water contact angle (WCA). Three-way ANOVA analysis reveals that all parameters, including polymerization time, UV irradiation time, and temperature are significant. The results show that by lowering the temperature below the lower critical solution temperature (LCST) of PNIPAAm, the microorganisms wholly detached from the surface. Therefore, PNIPAAm can release marine microorganisms, and it can be a suitable and environmentally friendly alternative for toxic antifouling coatings.

Ionic liquid-assisted sol-gel synthesis of Fe2O3-TiO2 for enhanced photocatalytic degradation of bisphenol a under UV illumination: Modeling and optimization using response surface methodology

This study was undertaken to synthesize Fe2O3-doped TiO2 nanoparticles using a long tail ionic liquid-assisted sol-gel method (IL-Fe2O3/TiO2) in order to photodegrade bisphenol A (BPA). Physicochemical properties of the synthesized photocatalysis were characterized through FTIR, FESEM-EDX, XRD, and DRS. The modeling and optimization of the photodegradation of BPA by IL/ Fe2O3-TiO2 were conducted with response surface methodology (RSM) by considering the central composite design (CCD). The results revealed that the 1-octadecyl-3-methylimidazolium bromide ([OMD]Br) ionic liquid, in combination with ferric oxide dopant, created low aggregated nanocomposites with a uniform and tiny grain size. 2.4 eV. bandgap energy was computed for IL-Fe2O3/TiO2. The quadratic model obtained from the ANOVA results of photodegradation processes. A BPA removal efficiency of 90.33 % was acquired under optimal conditions (IL-Fe2O3/TiO2 loading dose = 0.75 g/L, pH = 9, initial BPA concentration = 10 mg/L, and UV irradiation time = 97.5 min). The results indicated that the photodegradation of BPA was mostly affected by the variables of time, pH, and initial BPA concentration, respectively. Only the second term of the IL-Fe2O3/TiO2 loading dose as a variable had a significant effect on the efficiency of the process. The Langmuir–Hinshelwood model was selected to investigate photodegradation kinetics.

UV/H2O2, UV/H2O2/SnO2 and Fe/H2O2 based advanced oxidation processes for the degradation of disperse violet 63 in aqueous medium

The photodegradation of disperse violet 63 dye was investigated in aqueous solution using UV/H2O2, UV/H2O2/SnO2 and Fenton reagent. The maximum decolorization was achieved in 60 min with 50 mg l−1 of dye concentration. The suitability of each process depends upon dye concentration. The photo degradation is very effective at low dye concentration. The degradation percentage increased by enhancing initial amount of hydrogen peroxide and UV irradiation time. The influence of operational parameters like pH, H2O2 concentration, catalyst amount and dye concentration were investigated. After 60 min reaction time, the maximum decolorization of disperse violet 63 with UV/H2O2, UV/H2O2/SnO2 and Fe/H2O2 was 81%, 92.7% and 96.4% respectively. The results indicated that Fenton process had more photocatalytic activity for degradation of disperse violet 63 dye than that of UV/H2O2 and UV/H2O2/SnO2. After 60 min, the comparative decomposition order was Fe/H2O2 > UV/H2O2/SnO2 > UV/H2O2. It may be concluded that Fenton process could possibly be used for the remediation of toxic pollutants from textile effluents.

PHOTOCATALYTIC ACTIVITY OF TiO2/SiO2 PREPARED FROM SILICA CONTAINED IN VOLCANIC ASH FOR AMMONIA REMOVAL

This paper presents a study on the improvement of TiO2 photocatalytic activity by supporting it on SiO2 purified from the volcanic ash of the eruption of Merapi Mt. standing in Yogyakarta, Indonesia. The preparation of TiO2/SiO2 was conducted by the sol-gel method at various pH. The photocatalyst prepared were characterized by using XRD, FTIR, SEM, and DRUV spectrometry methods. The photocatalytic activity was examined for ammonia removal. The research results reveal that silica gel from the volcanic ash can be used for supporting TiO2 photocatalyst to successfully form nanoparticles with anatase type and to enhance its photocatalytic activity in the ammonia removal. The highest activity of TiO2/SiO2 was shown by photocatalyst prepared at pH 4. The ammonia removal was found to be controlled by photocatalysts dose, pH and the UV irradiation time, wherein the maximum ammonia removal (65%) from 50 mg/L in 100 mL solution was obtained by applying 50 mg of the photocatalyst dose, at pH 9, and 24 h of time. The ammonia removal was believed through oxidation reaction to form NO3 - ion and/or degradation to form N2 gas, but it has not been proved yet that needs to be further studied.

Synthesis and characterization of photocatalist TiO2 doped with Ni for treatment of waste model from nuclear facility

Synthesis and characterization of photocatalist TiO2 doped with Ni for treatment of waste model from nuclear facility. Ni doped TiO2 as photocatalyst material has been made. Addition of dopant Ni was carried out by impregnation technique. The Ni content was varied between 3, 5, 7 and 10 wt.%. The TiO2-Ni samples obtained were then characterized by X-Ray Diffractometer and SEM-EDS. The catalyst test is carried out using UV-VIS. The anatase crystal structure appears at 2θ = 25.41°, 37.89°, 48.13°, 55.14° 62.78°. The NiO crystal structure was also found at X-Ray peak 2θ = 38.8°. It obvious that addition of Ni dopants decreased significantly the TiO2 crystal main size The anatase crystal structure formed on TiO2-Ni (3 wt.%) is 84.21%. The results of SEM-EDS analysis showed the best success rate of 91.6% wt 3 wt.% Ni addition. The photocatalist material TiO2-Ni was then applied to treat the standard non-radioactive liquid waste material from BATAN nuclear facility modeled by a mixture based on methylene blue exposed with UV light with variation of time. The degradation rate during processing of methylene blue waste with TiO2-Ni (3 wt.%) using UV light was measured 0.021/hour. The longer the UV irradiation time is the greater the degradation of methylene blue. The making of TiO2 photocatalyst by adding variations of Ni dopant has been successfully caried out, with a fairly good success rate. The highest success rate is addition of Ni by 3% with a success rate of 91.6%.

Compression-Responsive Photonic Crystals Based on Fluorine-Containing Polymers.

Fluoropolymers represent a unique class of functional polymers due to their various interesting and important properties such as thermal stability, resistance toward chemicals, repellent behaviors, and their low refractive indices in comparison to other polymeric materials. Based on the latter optical property, fluoropolymers are particularly of interest for the preparation of photonic crystals for optical sensing application. Within the present study, photonic crystals were prepared based on core-interlayer-shell particles focusing on fluoropolymers. For particle assembly, the melt-shear organization technique was applied. The high order and refractive index contrast of the individual components of the colloidal crystal structure lead to remarkable reflection colors according to Bragg’s law of diffraction. Due to the special architecture of the particles, consisting of a soft core, a comparably hard interlayer, and again a soft shell, the resulting opal films were capable of changing their shape and domain sizes upon applied pressure, which was accompanied with a (reversible) change of the observed reflection colors as well. By the incorporation of adjustable amounts of UV cross-linking agents into the opal film and subsequent treatment with different UV irradiation times, stable and pressure-sensitive opal films were obtained. It is shown that the present strategy led to (i) pressure-sensitive opal films featuring reversibly switchable reflection colors and (ii) that opal films can be prepared, for which the written pattern—resulting from the compressed particles—could be fixed upon subsequent irradiation with UV light. The herein described novel fluoropolymer-containing photonic crystals, with their pressure-tunable reflection color, are promising candidates in the field of sensing devices and as potential candidates for anti-counterfeiting materials.

Hybrid Hydrophilic-Hydrophobic CuO@TiO2-Coated Copper Mesh for Efficient Water Harvesting.

Fresh water scarcity has been a worldwide problem to be solved urgently. Inspired by the outstanding hydrophobic-hydrophilic patterns on the back of Namib desert beetles, hierarchical CuO@TiO2-coated surface with alternating hydrophilic-hydrophobic chemistry patterns were fabricated utilizing the photocatalysis of titanium dioxide through ultraviolet irradiation. The results indicated that the as-prepared hybrid dual-coated copper mesh enhanced the fog-collection efficiency compared with the uniformly superhydrophobic or superhydrophilic surface. This enhancement can be regulated by controlling the deposition cycle times of TiO2 multilayers on CuO and UV irradiation time. The best water harvesting behavior was determined at the deposition cycle times of 10 times and UV irradiation time of 4 h. This work findings offer new insights into the fabrication of hybrid hydrophilic-hydrophobic surfaces for highly efficient water harvesting.

In Situ Production of Ag/Polymer Asymmetric Nanoparticles via a Powerful Light-Driven Technique.

As a rapid, controllable, and easily transferrable approach to the preparation of antimicrobial nanoparticle systems, a one-step, light-driven procedure was developed to produce asymmetric hybrid inorganic-organic nanoparticles (NPs) directly from a homogeneous Ag/polymer mixture. An amphiphilic triblock polymer was designed and synthesized to build biocompatible NPs, consisting of poly(ethylene oxide) (PEO), carboxylic acid-functionalized polyphosphoester (PPE), and poly(l-lactide) (PLLA). Unexpectedly, snowman-like asymmetric nanostructures were subsequently obtained by simply loading silver cations into the polymeric micelles together with purification via centrifugation. With an understanding of the chemistry of the asymmetric NP formation, a controllable preparation strategy was developed by applying UV irradiation. A morphology transition was observed by transmission electron microscopy over the UV irradiation time, from small silver NPs distributed inside the micelles into snowman-like asymmetric NPs, which hold promise for potential antimicrobial applications with their unique two-stage silver release profiles.

The effects of prolonged UV irradiation on the physicochemical characteristics of chitosan lamellar films modified with nanoparticulate silver vanadate nanorods

Chitosan–AgVO3 nanocomposites were synthesized via ordinary solution casting route at ambient room temperature. During UV prolonged irradiation, the structural and chemical changes were investigated using UV–Vis spectroscopy, Fourier transform infrared (FTIR) and X-ray diffraction analysis (XRD). Spectroscopic exploration of FTIR and UV–Vis indicated the photodegradation processes of prepared thin films. UV–Vis analysis confirmed the generation of new chromophoric groups after prolonged UV irradiation of synthesized lamellar nanocomposites polymer system probably assigned to photooxidation processes. The level of changes of such physicochemical characteristics may be considered to be dependent on the reactive functional groups on the chitosan surface, concentrations of inorganic lamellar dopant (AgVO3 nanorods), irradiation conditions and the time of UV irradiation. Primarily, this study provides the influential modification of chitosan with AgVO3 nanorods.

UV-irradiated gelatin-chitosan bio-based composite film, physiochemical features and release properties for packaging applications

In this study, Chitosan-Gelatin biodegradable films loaded with Gallic acid (GA) were developed. Ethanol, tween, and β-Cyclodextrin (β-CD) were used to enhance the distribution of GA in the film forming solutions. The effect of the exposure time of UV irradiation on the color, mechanical properties (TS, %E), water vapor permeability (WVP) microstructure and release rate of GA to fatty food simulants investigated. UV irradiation reduced darkness of the films markedly and increased the release rate of the GA. Among the non-irradiated samples the highest and lowest release rate were obtained for the films containing β-CD and ethanol respectively. On the other hand incorporation of β-CD could reduce the increasing effect of UV light on release rate. The UV irradiation for 10 min reduced mechanical strength and barrier properties of the film against water vapor. Microscopic analysis, showed the consistent and uniform microstructure. However, long-term radiation caused some cracks in the films network. The UV irradiation weakened the _OH bending and enhanced the amide I amide II.

Photocatalytic Removal of Methyl Orange Azo Dye with Simultaneous Hydrogen Production Using Ru-Modified ZnO Photocatalyst

The aim of this work is to demonstrate the effectiveness of the photocatalytic process in the Methyl Orange azo dye degradation and simultaneous H2 production by using ZnO doped with ruthenium. Ru-modified ZnO photocatalysts were prepared by precipitation method and were characterized by different techniques (XRF, Raman, XRD, N2 adsorption at −196 °C, and UV–vis DRS). The experiments were carried out in a pyrex cylindrical reactor equipped with a nitrogen distributor device and irradiated by four UV lamps with the main wavelength emission at 365 nm. Different Ru amounts (from 0.10 to 0.50 mol%) were tested in order to establish the optimal amount of the metal to be used for the ZnO doping. The photocatalytic activity was evaluated both in terms of Methyl Orange removal and hydrogen production. The experimental results showed that the best activity, both in terms of H2 production and Methyl Orange degradation, was obtained with the Ru-modified ZnO photocatalyst at 0.25 mol% Ru loading. In particular, after four hours of UV irradiation time, the discoloration and mineralization degree were equal to 83% and 78%, with a simultaneous hydrogen production of 1216 µmol L−1. This result demonstrates the ability of the photocatalytic process to valorize a dye present in wastewater, managing to obtain a hydrogen production comparable with the data present in the literature today in the presence of other sacrificial substances.

Photodeposition time dependant growth, size and photoactivity of Ag and Cu deposited TiO2 nanocatalyst under solar irradiation

Ag and Cu metals due to their strong surface plasmons and visible light sensitivities have been incorporated with TiO2 for various solar applications. But the effect of mutual interaction between these two metals and role of photodeposition (PD) time has not been studied which may bring new interfaces, more photonic absorptions and photocatalytic activities. So, the present work focuses not only on the enhanced photoactivity of binary deposition of Ag and Cu metal onto TiO2 compared to their monometallic counterparts but on the importance of wt% and PD time as well. The higher activity possessed by the binary metal deposited TiO2 catalyst has been credited to greater interfacial contact region, optimized photodeposition time and enhanced absorptions in the visible region. Further, Ag-Cu@TiO2 photocatalyst was optimised by varying the wt% and PD time (15, 30, 60 and 90 min.) of deposited metals. It was observed that with increase in PD time, the DRS intensity (400–700 nm) also increased in the respective manner. It has been established that the co-catalyst size and growth of nanoparticles (evidenced by TEM, EDS and DLS analysis) play a major role which vary as a function of UV irradiation time during preparation of nanocatalyst. Consequently, Ag-Cu@TiO2 co-catalyst prepared at 30 min PD time has been shown to have maximum co-catalytic activity for the degradation of neutral red (k × 10−3 = 0.061 min−1) and phenol red (k = 0.028 min−1) dyes under solar irradiation which has been attributed to the controlled growth and well dispersed Ag-Cu nanodeposits.