UV-C Light Irradiation Research Articles

Cationic Dye Degradation and Real Textile Wastewater Treatment by Heterogeneous Photo-Fenton, Using a Novel Natural Catalyst

A photo-Fenton process using a local iron oxide as a natural catalyst was compared to Fenton and UV/H2O2 advanced oxidation processes for degrading crystal violet (CV) dye in aqueous solutions. The catalyst was characterized by transmission electron microscopy (TEM), energy dispersive X-ray microanalysis (EDX), Fourier transform infrared spectroscopy (FT-IR), Raman spectrum, X-ray diffraction (XRD), UV-vis spectroscopy, and Brunauer–Emmett–Teller (BET) analysis. The optical properties proved that the catalyst represents a good candidate for photocatalytic activity. The impact of different parameters (catalyst dose, initial CV concentration, initial H2O2 concentration, pH) on the photo-Fenton efficiency was evaluated. A photo-Fenton process operated under UVC light irradiation, at spontaneous pH, with 1.0 g/L of catalyst and 30 mg/L of H2O2 was the most effective process, resulting in 98% CV dye removal within 3 h. LC-MS and ion-chromatography techniques were used to identify demethylated organic intermediates during the process. Furthermore, a regeneration study of the catalyst showed its stability and reusability (after three treatment cycles, CV dye degradation decreased from 94% to 83%). Finally, the photo-Fenton process was tested in the treatment of real textile wastewater, and the effluent was found to be in compliance with standards for industrial wastewater disposal into sewerage.

Immobilization of TiO2 Semiconductor Nanoparticles onto Posidonia Oceanica Fibers for Photocatalytic Phenol Degradation

A new composite photocatalyst called POF/TiO2 was prepared from commercial P25 TiO2 and Posidonia oceanica fibers (POF), a biomaterial collected from Tunisia’s beach. The composite material was prepared by a classical sol-gel synthesis and was characterized by different methods. SEM images show a TiO2 layer formed on top of the fibers, which was verified by XRD and XPS. Diffuse reflectance UV-vis spectroscopy shows that the layer has the same optical properties (Eg = 3.0 eV) as bulk P25. The photodegradation of phenol as a model compound was studied under different operating conditions using POF/TiO2 and the results show degradation efficiencies between 4% (100 ppm) and 100% (<25 ppm) after 4 h of UV-C light irradiation (254 nm) using a POF/TiO2 concentration of about 1 g/L. The composite material showed good stability and could be recycled up to three times.

Light Tailoring: Impact of UV-C Irradiation on Biosynthesis, Physiognomies, and Clinical Activities of Morus macroura-Mediated Monometallic (Ag and ZnO) and Bimetallic (Ag-ZnO) Nanoparticles.

A nano-revolution based on the green synthesis of nanomaterials could affect all areas of human life, and nanotechnology represents a propitious platform for various biomedical applications. During the synthesis of nanoparticles, various factors can control their physiognomies and clinical activities. Light is one of the major physical factors that can play an important role in tuning/refining the properties of nanoparticles. In this study, biocompatible monometallic (AgNPs and ZnONPs) and bimetallic Ag–ZnONPs (0.1/0.1 and 0.1/0.5) were synthesized under UV-C light irradiation from the leaf extract of Morus macroura, which possesses enriched TPC (4.238 ± 0.26 mg GAE/g DW) and TFC (1.073 ± 0.18 mg QE/g DW), as well as strong FRSA (82.39%). These green synthesized NPs were evaluated for their anti-diabetic, anti-glycation, and biocompatibility activities. Furthermore, their anti-cancerous activity against HepG2 cell lines was assessed in terms of cell viability, production of reactive oxygen/nitrogen species, mitochondrial membrane potential, and apoptotic caspase-3/7 expression and activity. Synthesized NPs were characterized by techniques including ultraviolet-visible spectroscopy, SEM, EDX, FTIR, and XRD. UV-C mediated monometallic and bimetallic NPs showed well-defined characteristic shapes with a more disperse particle distribution, definite crystalline structures, and reduced sizes as compared to their respective controls. In the case of clinical activities, the highest anti-diabetic activity (67.77 ± 3.29% against α-amylase and 35.83 ± 2.40% against α-glucosidase) and anti-glycation activity (37.68 ± 3.34% against pentosidine-like AGEs and 67.87 ± 2.99% against vesperlysine-like AGEs) was shown by UV-C mediated AgNPs. The highest biocompatibility (IC50 = 14.23 ± 1.68 µg/mL against brine shrimp and 2.48 ± 0.32% hemolysis of human red blood cells) was shown by UV-C mediated ZnONPs. In the case of anti-cancerous activities, the lowest viability (23.45 ± 1.40%) with enhanced ROS/NOS production led to a significant disruption of mitochondrial membrane potential and greater caspase-3/7 gene expression and activity by UV-C mediated bimetallic Ag–ZnONPs (0.1/0.5). The present work highlights the positive effects of UV-C light on physico-chemical physiognomies as well as the clinical activities of NPs.

Exploring the Potentialities of Photoinduced Glycation to Steer Protein Functionalities: The Study Case of Freeze-Dried Egg White Proteins/Carbohydrates Mixtures.

The capacity of UV-C light to induce glycation and modify functional properties of systems containing freeze-dried egg white proteins and carbohydrates with increasing molecular weight (i.e., glucose, maltose, trehalose and maltodextrin) was studied. Color changes induced by light exposure were taken as typical indicators of glycation. Samples were then analyzed for selected physical (critical concentration, particle size and viscosity), chemical (ovalbumin content) and technofunctional properties (gelling temperature and foaming capacity). The presence of sugars during exposure to UV-C light promoted intense browning and decreased ovalbumin content by circa 30%. Concomitantly, up to a 3-fold increase in critical concentration of the aqueous suspensions of the irradiated protein-carbohydrate powders and changes in particle size were detected. These modifications were consistent with the development of non-enzymatic browning reactions upon UV-C light irradiation. Photoinduced glycation was associated to a decrease in viscosity, a tendency to form gel at temperature lower by up to 8 °C and a better capacity of foam stabilization. The intensity of these changes seems to be affected by the nature of the carbohydrates reacting with proteins, with longer carbohydrates able to produce systems with higher foam stability capacity.

Fabrication and characterization of a novel silk fibroin film with UV and thermal resistance

Silk fibroin is an excellent material for use in tissue engineering owing to its biocompatibility and biodegradability. For proper sterilization, it is necessary to investigate the properties of the material after irradiation with ultraviolet rays prior to implementation. In this study, grinded silk fibroin (GF) films with an ultraviolet (UV)-resistant property using a grinding method without the application of an organic solvent have been successfully prepared. A regenerated silk fibroin (RF) film using a conventional method was also prepared as a comparative sample. The Fourier transform infrared spectroscopy (FT-IR) and atomic force microscope (AFM) results show that the surface of the RF film was photo-oxidized with UV-C light irradiation and that the fibroin molecular chains were decomposed. Furthermore, the modulus of the RF film decreased. However, almost no oxidation deterioration or shape change of the film surface occurred when UV-C light was irradiated on the developed GF film, indicating that the thermal-decomposition temperature and mechanical properties maintained their initial values. These results strongly suggest that GF films prepared using the novel approach have superior thermal and mechanical properties compared with RF films prepared through a conventional method. In addition, GF films achieve a superior UV-C resistance property.

UV-C radiation effect on nuclear tracks of different ions in polycarbonate

The neutron autoradiography technique was developed in our laboratory using polycarbonate nuclear track detectors, to qualitatively and quantitatively analyze boron distribution and concentration in biological samples from experimental models coming from Boron Neutron Capture Therapy research. Spatial resolution was later improved by generating an imprint of the biological sample (e.g. cellular culture, tissue sections) on the detector surface, which can be microscopically observed together with nuclear tracks originated by 10B capture products. This methodology was developed for polycarbonate detectors and involves UV-C light irradiation of the sample-detector assembly. The chemical etching process of the detector, usually performed to enlarge the nuclear tracks, also “reveals” the imprint of the sample.In this work we report a fading effect in nuclear tracks due to UV-C exposure. Significant differences in track density produced by alpha ions and Li recoils coming from the neutron capture reaction, 10B(n,α)7Li, were found between exposed and unexposed to UV-C light (254 nm wavelength) polycarbonate foils. A decreasing relation between track density and exposure time to UV-C radiation could also be observed for these ions. To analyze the effect produced by UV-C radiation on nuclear tracks of different ions, polycarbonate detectors irradiated with 7Li, 12C, 16O, 32S, 127I, 197Au beams and air degraded alpha particles from a241Am source were also studied. A wavelength dependent photodegradation mechanism affecting the polycarbonate detector would be altering the nuclear tracks development in different ways, according to ion damage characteristics.

IMPACT OF TiO2 AND H2O2 ON PHOTOCATALYTIC DEGRADATION OF PHODAMINE B UNDER ULTRAVIOLET C (UV-C) RADIATION FOR EFFICIENT POLLUTED WASTEWATER TREATMENT

Photocatalytic wastewater treatments applying the semiconductor photocatalysts to remove toxins or pollutants from wastewater become more important nowadays. In this study, the photocatalytic study was firstly conducted on the photodegradation of rhodamine B (RB) dye in tap water by using TiO2 as photocatalysts under short wavelength (high energy) UV-C light irradiation. The results show that a considerable increase in the degradation of RB can be obtained through a combination of TiO2 and UV-C light. In addition, hydrogen peroxide (H2O2) was added in the RB solution containing TiO2 to improve the degradation efficiency of RB dyes. The result shows that 98 % degradation efficiency of 20 ppm RB is achieved within 180 min irradiation time in the solution containing 0.5 g/l TiO2 and 1 M H2O2 concentrations, which is higher than the reported literature value.

Magnetised photocatalyst TiO2/Fe3O4 nanocomposite capable to photodegrade organic dye

In this study, methylene blue (MB) is used as a measure of the photocatalytic capabilities of the prepared TiO2/Fe3O4 photocatalyst nanocomposite. The nanocomposite was suspended in the dye aqueous solutions placed in a UV chamber under UV-C (254 nm) light irradiation. The TiO2/Fe3O4 nanocomposite was characterised by XRD, FESEM, TEM and EDX analysis. The TiO2/Fe3O4 nanocomposite crystal structure retained TiO2 pure anatase of tetragonal crystal structure (SG: I4/amd) and Fe3O4 cubic spinel crystal structure with average crystalline size of (62.1 ± 5.7) nm. The optimum performance of the magnetic nanocomposite was monitored through few categories, such as concentration of photocatalyst, doping amount of Fe3O4 nanoparticle into the nanocomposite and sintering temperature. The TiO2/Fe3O4 nanocomposite optimum loading was detected at 3.0 wt%. The nanocomposite performed well at 1 wt% of Fe3O4 doping and 350 °C of sintering temperature. The reliability of the TiO2/Fe3O4 nanocomposite was also conducted where it was successfully repeated for at least 3 times with no obvious changes observed in the degradation efficiency.

Ferrite@TiO2-nanocomposites as Z-scheme photocatalysts for CO2 conversion: Insight into the correlation of the Co-Zn metal composition and the catalytic activity

Photocatalytic conversion of CO2 in the gas phase involving Z-scheme mechanism was studied in the presence of CoxZn1-xFe2O4@TiO2 (x = 1; 0.2; 0.4; 0.6; 0.8; 0) catalyst nanocomposites. The catalysts were obtained in a two-step approach, consisting of a co-precipitation reaction forming the magnetic Ferrite nanoparticles and a hydrolysis-condensation reaction of the Ti-source forming the titania anatase phase, followed by a calcination procedure. The structural characterization was done by X-ray diffraction, Raman and UV-DR spectroscopy, and physisorption, confirming the presence of both structures in the nanocomposites, with a band gap between 3 and 3.23 eV. In order to determine the CO2 conversion, a photocatalytic gas phase fixed-bed batch reactor in tandem with a GC analyzer were used. The tests were done under UVC light irradiation and CO, CH4 were identified as the main products during photoconversion of CO2. All the samples showed higher conversions compared to the well-known reference material P25 (Degussa). The CO2 conversion was observed to be directly proportional with the Zn/Co metal ratio in the Ferrite structure, achieving for ZnFe2O4@TiO2 ∼50 μmol gcat.-1 h-1 CO and ∼30 μmol gcat.-1 h-1 CH4. Moreover, for the ZnFe2O4@TiO2 catalyst methanol (CH3OH) formation was observed, while no traces of methanol were detected for the samples containing Co. The electrochemistry analyses clarified the different heterojunctions formed between Ferrites and TiO2. Mott-Schottky plots revealed the formation of a Z-scheme mechanism for ZnFe2O4@TiO2 explaining the best conversion results. On the other hand, the lower activity of CoFe2O4@TiO2 was attributed to the formation of a type I heterojunction system.

Solid-phase photocatalytic degradation of polyaniline under UVA and UVC light irradiation

ABSTRACT In this study, pure polyaniline (PANI0) and polyaniline/titanium dioxide composites, including 15 wt.% TiO2 (PANI15) and 25 wt.% TiO2 (PANI25), respectively, were synthesised using an in-situ polymerisation technique in the absence and in the presence of titanium dioxide nanoparticles, respectively. The solid-phase photocatalytic degradation of polyaniline/titanium dioxide (TiO2) composites was compared with that of the pure polyaniline with the aid of weight loss measurements. The structural and morphological properties of the prepared samples were studied by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray analysis, thermogravimetric analysis and X‐ray diffraction analysis. The loading of TiO2 nanoparticles in polyaniline enhanced the solid-phase photocatalytic degradation of the pure polymer both under UVA light and under UVC light, respectively. Fourier transform infrared spectroscopy illustrated that Pani was synthesised successfully in the presence of TiO2 nanoparticles. Field emission scanning electron microscopy revealed homogeneous TiO2 dispersion within Pani matrix. Thermogravimetric analysis supported the idea that the thermal property of the pure polymer was improved with the photocatalyst contribution. The crystalline structure of TiO2 did not change with Pani.

Investigation of metal oxides toward organic dyes decolourisation and environmental remediation

Enormous interest has been focused on metal oxides in its photocatalytic capabilities toward oxidizing organic dyes and environmental remediation. Zinc oxide (ZnO), titanium dioxide (TiO2) and iron oxide (Fe3O4) have been used as the heterogeneous photocatalysts to photodegrade three organic dyes, which are methylene blue (MB), phenol red (PR) and methyl orange (MO). Series of 3.0 ml dyes samples in aqueous solutions were placed into a UV chamber under UV-C (254 nm) light irradiation. The oxides powder was characterised by XRD, FESEM and TEM analysis, where ZnO nanoparticles was in hexagonal wurtzite crystal structure (SG: P63mc) with average crystalline size of (91 ± 12) nm and TiO2 nanoparticles was pure anatase of tetragonal crystal structure (SG: I4/amd) with average crystalline size of (117 ± 16) nm. Fe3O4 nanoparticles was in cubic spinel crystal structure with average crystalline size of (62.1 ± 5.7) nm. The photocatalyst loading (0.5 – 3.5wt%), initial dye concentration (MB: 2 – 12 ppm, PR: 8 – 48 ppm, MO: 12 – 32 ppm) and irradiation duration on the decolourisation of dye samples were examined. Based on time requirement, the photocatalytic decolourisation rate increased with increasing metal oxide loading and decreased with the increasing of the initial dye concentration. The superior photocatalyst was ZnO with a loading of 2.5 wt% followed by TiO2 (3.0 wt%) and least photocatalytic capability was Fe3O4 (3.0 wt%). On the other hand, the most photostable dye is MO followed by PR and MB.

Photostability of quantum dot micelles under ultraviolet irradiation.

Phospholipid quantum dot micelles are useful for bio-applications because of their amphiphilicity and exceptional biocompatibilities. We investigated the uptake of phospholipid [polyethylene glycol (PEG), biotin, and folic acid terminated] modified CdSe/ZnS quantum dot micelles by cancer cells and its photostability under ultrviolet light in the C spectrum (UV-C) (254nm) or UV-A (365nm) light irradiation. The stability of micelles to the exposure of UV-C and UV-A light was assessed. Biotin-modified quantum dot micelles give photoluminescence enhancement under UV-C light irradiation. Folate modified micelle under UV-C and UV-A results show considerable photoluminescence enhancement. Photoluminescence lifetime measurements showed 7.04, 8.11 and 11.42ns for PEG, folate, and biotin terminated phospholipid micelles, respectively. Folate and biotin-modified quantum dot micelles showed excellent uptake by HeLa cells under fluorescence confocal microscopy. Phospholipid CdSe/ZnS quantum dot micelles can be potentially used for diagnosis and treatment of cancer in the future.

Astaxanthin Has a Potential Role in Antioxidation and Oxidative Damage Repair in UVC Irradiated Mice

The anti-oxidative activity and oxidative damage repair potential of dietary AS in UVC irradiated mice was studied in present study. The activities of superdismutase (SOD) and glutathione peroxidase (GPx) in the liver and serum of mice increased dramatically at treatment with a dose of 100 mg/kg bodyweight AS during 10 days UVC light irradiation in comparison with the control group. Concurrently, the gene expression levels of sod1, sod2, gpx1 and gpx2, as determined by real-time quantitative PCR, were also up-regulated in the liver in the AS treated group during the UVC irradiation. For further understanding the oxidative damage repair potential of dietary AS in UVC irradiated mice, after 7 days AS and VE treatment, the SOD and GPx activities also increased significantly in liver and serum in mice fed with AS compared to the UVC light treated group. The results obtained here strongly suggested that AS reduces the UVC irradiation oxidative stress dramatically in short time.

Eggshell microbiology and quality of hatching eggs subjected to different sanitizing procedures

Abstract: The objective of this work was to evaluate the effect of different disinfection procedures as alternatives to formaldehyde fumigation on eggshell microbial load and quality of eggs from a 42-week-old Cobb commercial breeder flock. A total of 10,080 clean eggs collected from the nests were randomly distributed in a randomized complete block design, among the following treatment groups: 13.33 g m-3 formaldehyde fumigation, 5-10 ppm ozone fumigation, 6.36 mW cm-2 UV-C light irradiation, spraying with 1.56% hydrogen peroxide, spraying with 0.13% peracetic acid, spraying with water (wet control), and no disinfection procedure (dry control). Per treatment, eight samples of four eggs each were collected before and after the disinfection procedure, in order to count the number of Enterobacteriaceae and total aerobic mesophilic bacteria on the eggshell. Only eggs subjected to the formaldehyde and UV treatments showed a significant reduction in total aerobic mesophilic bacterial count on the eggshell, when compared with those of the dry control group. Treatments did not affect eggshell thickness and resistance force. UV light exposure is effective in reducing microbial load on 42-week-old breeder flock eggshells, without affecting their quality, and can be considered an alternative to formaldehyde disinfection.

UV-C light irradiation enhances toxic effects of chlorpyrifos and its formulations

UV-C irradiation is widely used in the food industry. However, the health effects from dietary exposure to the irradiated pesticide residues retained in foodstuffs are underestimated. In this study, technical chlorpyrifos (TCPF) and its oil in water (EW) and emulsifiable concentrate (EC) formulations were irradiated by UV-C, and their photodegradation products were subjected to toxicity assessment, including determination of acetylcholinesterase (AChE) activity, genotoxicity and oxidative stress using human blood cells as a model system. Toxicity studies were performed using the chlorpyrifos concentrations in the range of those proposed as the maximum residue levels in plant commodities. TCPF, EW and EC photodegradation products induced DNA damage and oxidative stress, and their genotoxicity did not decrease as a function of irradiation time. Irradiated TCPF and EC are more potent AChE inhibitors than irradiated EW. Accordingly, the application of UV-C irradiation must be considered when processing the plants previously treated with chlorpyrifos formulations.

Oxidation of ethylenethiourea in water via ozone enhanced by UV-C: identification of transformation products.

Ethylenethiourea (ETU) is a toxic degradation product of one class of fungicide which is largely employed in the world, the ethylenebisdithiocarbamates. In this study, ETU was degraded by ozonation enhanced by UV-C light irradiation (O3/UV-C) in aqueous medium. Degradation experiments were conducted at natural pH (6.8) and neutral pH (7.0, buffered). ETU was promptly eliminated from the reactive medium during ozonation in the presence and absence of light. Within the first few minutes of reaction conducted in natural pH, the pH decreased quickly from 6.8 to 3.0. Results show that ETU mineralization occurs only in the reaction conducted in neutral pH and that it takes place in a higher rate when enhanced by UV-C irradiation. Main intermediates formed during the O3/UV-C experiments in different conditions tested were also investigated and three different degradation mechanisms were proposed considering the occurrence of direct and indirect ozone reactions. At pH 7, ethylene urea (EU) was quickly generated and degraded. Meanwhile, at natural pH, besides EU, other compounds originated from the electrophilic attack of ozone to the sulfur atom present in the contaminant molecule were also identified during reaction and EU was detected within 60min of reaction. Results showed that ozonation enhanced by UV-C promotes a faster reaction than the same system in the absence of light, and investigation of the toxicity is recommended.

Single cyanobacteria@silica porous microcapsules via a sol–gel layer by layer for heavy-metal remediation

Heavy-metal removal from industrial wastewater is a major issue. The use of microbial biosorbent is a low cost, sustainable, and efficient way for water cleaning, but the living organisms are limited by their sensitivity and fragility and subjected to water contamination by other relevant bacteria. In order to improve the use of the powerful photosynthetic prokaryote, this work focused on the development of a new protection method of cyanobacterial strains of the genus Synechococcus sp. PCC7002 by a multiple coating including an external layer made of silica. This surfacing was performed using the layer-by-layer method and different polyelectrolytes. Polydiallyldimethylammonium chloride, a cationic polymer is used as a link between the cell wall and silica shell, while polystyrene sulfonate is inserted to play a protective role against ultraviolet light irradiation. This study discloses the synthesis of a highly efficient hybrid material and the excellent protection brought by the silica material. First of all, the layers, in particular four layers, deposited around single cells offer a strong protection against very harmful UV-C light irradiation while maintaining high viability and the same bioadsorption capacity for heavy-metal ions in solution. The long-term viability of this living material and its successful use for copper and lead sequestration, confirms the possibility of exploiting encapsulated cyanobacteria to improve current biotechnologies for wastewater purification.

CTAB and SDS assisted facile fabrication of SnO2 nanoparticles for effective degradation of carbamazepine from aqueous phase: A systematic and comparative study of their degradation performance

In the present study, SnO2 nanoparticles were successfully synthesized by chemical precipitation method using anhydrous aspartic acid and surfactant at two annealing temperatures, 300 °C and 600 °C. The effect of surfactants cationic CTAB and anionic SDS on the synthesized SnO2 nanoparticles (NPs) were studied elaborately. In this article, for the first time, SnO2 NPs were employed as an excellent photocatalyst in the degradation of carbamazepine (CBZ), a popular antiepileptic drug which is most commonly detected pharmaceutically active compounds (PhACs) in municipal wastewater under UV-C light irradiation. Comparative studies between the photocatalytic activity of SnO2 NPs synthesized with CTAB (SC1) and SDS (SS1) on the degradation of the CBZ drug were investigated. Parameters like the effect of catalytic loading, initial concentration, pH and contact time were also studied for optimization. The results indicate that SC1 is a better photocatalyst with rate constant 6.66 × 10−2 min−1 than SS1 with rate 5.7 × 10−2 min−1. To determine the transformation product formed on the photodegradation LCMS (ESI) analysis was done. The synthesized SnO2 NPs can be recycled up to 8th cycles without any notable alteration in its photocatalytic activity.

Photocatalytic degradation of imidacloprid pesticide in aqueous solution by TiO2 nanoparticles immobilized on the glass plate

ABSTRACTThe purpose of this study is to appraise the photocatalytic degradation of imidacloprid pesticide in an aqueous solution. To this end, imidacloprid was degraded using TiO2 nanoparticles immobilized on a glass plate under UV light illumination. The effects of operational parameters (initial concentration of imidacloprid, pH, and light intensity) on the activity of TiO2 nanophotocatalyst and the kinetics of the reaction were investigated. The results indicated that TiO2 had impressive photocatalytic proficiency in the presence of UV-C light irradiation for the removal of imidacloprid from the aqueous solution. The highest efficiency for the removal of imidacloprid (R% = 90.24) was obtained in the initial concentration of 20 mg L−1 imidacloprid, pH = 5, and light intensity of 17 W m−2 after 180 min. The results of the mineralization studies represented a subtractive trend of total organic carbon (TOC) and an increase in the mineralization products during the reaction time.

Polyaniline/ZnS nanocomposite as a novel photocatalyst for removal of Rhodamine 6G from aqueous media: Optimization of influential parameters by response surface methodology and kinetic modeling

Novel polyaniline/zinc sulfide (PANI/ZnS) nanocomposite in the role of photocatalyst was synthesized via a simplified method and was characterized by XRD, FT-IR, EDX and FE-SEM analysis. Modeling and optimization of photocatalytic removal of a hazardous xanthine dye, Rhodamine 6G (Rh-6G) from aqueous media by prepared nanocomposite was conducted using response surface methodology (RSM). Under optimum conditions (initial Rh-6G concentration=4mgL−1, PANI/ZnS amount=0.8gL−1, pH=8 and irradiation time=48min) and exposure of UV-C light irradiation (20Wm−2), photocatalytic process led to a remarkable removal of Rh-6G dye (80.62%). Reusability study of photocatalyst revealed a negligible decline of the process yield after five consecutive cycles. In continuation of our investigations, an empirical equation was obtained for estimation of apparent pseudo first- order rate constant (kap) as a function of influential parameters. In the final stage of the work, intermediate materials produced within photocatalytic degradation of Rh-6G dye were detected by GC–MS analysis.