Carcinogenic Dyes Research Articles

Biomass-derived activated carbon/cerium oxide nanocomposite as adsorptive photocatalyst for effective removal of carcinogenic dye

Semiconductor-based photocatalysts offer potential solutions for carcinogenic dye-related issues in water under light irradiation. However, their efficiency is affected by the recombination of photoelectrons and holes. The present study focuses on synthesizing biomass-derived activated carbon (AC), Cerium Oxide (CeO2), and AC/CeO2 (ACO) nanocomposites for toxic dye degradation. The physicochemical properties of samples were analyzed by XRD, SEM, EDX, TEM, UV–visible, Raman, XPS, and PL analysis. The photocatalytic performance of AC, CeO2, and ACO nanocomposites was evaluated under dark and light conditions for the removal of carcinogenic Rhodamine B (RhB). ACO nanocomposites exhibited adsorptive-photocatalytic performance, displaying unique adsorption and photocatalytic degradation rates due to their synergistic combination. Remarkably, the ACO-4 composite showed lower recombination of e−/h+ pairs, thereby exhibiting superior photocatalytic activity compared to other samples. The degradation rate constant under light was 0.1815 min⁻¹ with a half-life time of 3.81 min, whereas in dark, it was 0.0665 min⁻¹ with a half-life time of 10.42 min.

Optimizing the % swelling and removal of carcinogenic dye from waste-water using polyacrylamide-based hydrogels

Nowadays due to rapid industrialization to assist humans, hazardous and non-biodegradable dyes are eliminated from leather and textile industries in water streams. To eradicate these toxic dyes, the adsorption process opted for wastewater reclamation. Therefore, polyacrylamide-based hydrogels were fabricated using methylene Bis acrylamide and FeCl3 as chemical and physical cross-linkers. Sodium alginate-co-Polyacrylamide-co-acrylic acid a ter-copolymer hydrogel cross-linked via N, N’ ˊ methylene bisacrylamide shows maximum %swelling at pH 9 i.e. 751.42% and an equilibrium time of 200 min. The sorption capacity obtained for ASM0.1 was maximum i.e. 43.809 ± 0.569 mg/g as compared to the sorption capacity of AAM0.05 and AAF0.05 i.e. 41.18 ± 0.541 mg/g and 35.588 ± 0.924 mg/g. The kinetic model followed by sorption of methylene blue onto polyacrylamide-based hydrogels was pseudo-second-order whereas diffusion occurred in two phases through macropores and mesopores. The optimized pH recorded for sorption is pH 9 having an adsorption value of 94.16 ± 1.326 mg/g. Batch experiments revealed that adsorption increases from 37.52 ± 0.743 mg/g to 104.56 ± 1.194 mg/g for ASM 0.1 with an increase in concentration from 20 mg/L to 60 mg/L. The isotherm model followed by MB sorption is the Freundlich isotherm model which infers the physical nature of sorption. Moreover, with an increase in temperature, the adsorption slightly increased from 89.31 mg/g to 92.14 mg/g due to an increase in kinetic energy with temperature rise. % Removal stability was investigated for 5 consecutive cycles and inferred that ASM0.1 has decreased its % removal by only 6.5% after five cycles.

A d10-Cd Cluster Containing Sandwich-Type Arsenotungstate Exhibiting Fluorescent Recognition of Carcinogenic Dye in Methanol.

A d10-Cd cluster containing sandwich-type arsenotungstate [C3H12N2]6[Cd4Cl2(B-α-AsW9O34)2] was synthesized and its structure characterized through elemental analyses, X-ray powder diffraction (XRPD), IR spectroscopy, X-ray photoelectron spectroscopy (XPS), and single-crystal X-ray diffraction. The X-ray analysis revealed that the molecular unit of the compound consists of a captivating tetra-Cd-substituted sandwich-type polyoxoanion, accompanied by six elegantly protonated 1,2-diaminopropane as counter ions. The further novelty of the tetranuclear cadmium cluster lies in its occupied chlorine atom sites. This makes it highly susceptible to coordinate reactions with nitrogen on polycyclic aromatic hydrocarbons, thereby exhibiting different fluorescent signals that facilitate the identification and detection of these carcinogenic substances in methanol.

Transforming waste to purity: 3D electro-Fenton process boosted with pistachio shell-derived iron-biochar electrode for methyl violet 2B dye catalytic removal

Traditional degradation methods with typical catalysts which have limited negatively charged surfaces are not effectively degrade cationic dyes. A multi-functional iron-biochar was prepared from waste pistachio shells (Fe@PSB) that offers enhanced dye removal due to abundance of negatively charged sites for the degradation of the carcinogenic dye known as methyl violet 2B (MV 2B) in a cutting-edge three-dimensional electrochemical Fenton system (3DEF) with graphite (GP) cathode and Titanium (Ti) anode (3DEF-Ti/GP). Catalytic properties of Fe@PSB were explored for MV 2B dye degradation at broad acidic pH range. At optimum operating conditions of the current of 2.0A, pH 5.0, and Na2SO4 dose of 0.2M, nearly 98.8% of 10mg/L MV 2B dye removal was attained in 60min of electrolysis time. Commercial particle electrodes did not perform as well for the MV 2B dye degradation. The catalytic mechanism of 3DEF-Ti/GP system was investigated by quenching experiments which revealed that the hydroxyl radical (•OH) was responsible for the oxidation of dye molecules. Fe@PSB significantly performed up to four successful cycles. Liquid chromatography-mass spectrometry analysis revealed that de-methylation was the primary degradation pathway. This unique approach not only valorizes agricultural waste but also paving the way for greener environmental solutions.

Formulation of silver phosphate/graphene/silica nanocomposite for enhancing the photocatalytic degradation of trypan blue dye in aqueous solution

Photocatalytic degradation of several harmful organic compounds has been presented as a potential approach to detoxify water in recent decades. Trypan Blue (TB) is an acidic azo dye used to distinguish live cells from dead ones and it's classified as a carcinogenic dye. In this study, silver phosphate (Ag3PO4) nanoparticles and novel Ag3PO4/graphene/SiO2 nanocomposite have been successfully prepared via simple precipitation method. Afterward, their physical properties, chemical composition, and morphology have been characterized using SEM, EDS, TEM, SAED, BET, XRD, FTIR and UV–VIS spectroscopy. The specific surface area of Ag3PO4 and Ag3PO4/G/SiO2 nanocomposite were reported to be 1.53 and 84.97 m2/g, respectively. The band gap energy of Ag3PO4 and Ag3PO4/G/SiO2 nanocomposite was measured to be 2.4 and 2.307 eV, respectively. Photocatalytic degradation of Trypan blue (TB) was studied at different parameters such as pH, catalyst dosage, initial concentration, and contact time. The results showed that, at initial dye concentration of 20 ppm, pH = 2, and using 0.03 g of Ag3PO4/G/SiO2 as a photocatalyst, the degradation percent of TB dye in the aqueous solution was 98.7% within 10 min of light exposure. Several adsorption isotherms such as Langmuir, Freundlich, and Temkin adsorption isotherms have been tested in addition to the photocatalytic degradation kinetics. Both catalysts were found to follow the Langmuir isotherm model and pseudo-second-order kinetic model. Finally, the possible photocatalytic performance mechanism of Ag3PO4/G/SiO2 was proposed.

Illegal synthetic dyes in spices: a Singapore case study

ABSTRACT Some synthetic dyes are fraudulently added into spices to appeal visually to consumers. Food regulations in several countries, including the United States, Australia, Japan and the European Union, strictly prohibit the use of unauthorised synthetic dyes in food. Nevertheless, illegal practices persist, where spices contaminated with potentially carcinogenic dyes have been documented, posing potential health risks to consumers. In the present study, 14 synthetic dyes were investigated through liquid chromatography/tandem mass spectrometry in 252 commercially available spices in the Singapore market. In 18 out of these (7.1%) at least 1 illegal dye was detected at concentrations ranging from 0.010 to 114 mg/kg. Besides potential health risks, presence of these adulterants also reflects the economic motivations behind their fraudulent use. Findings in the present study further emphasise the need for increased public awareness, stricter enforcement, and continuous monitoring of illegal synthetic dyes in spices to ensure Singapore’s food safety.

Role of ZnO/GO nanocomposite in photocatalytic degradation of mixture of organic pollutants and antimicrobial activity

AbstractA number of carcinogenic dyes and microbial infections have negative effects on living being. These also have a detrimental effect on water quality and responsible for major health problems. ZnO/GO nanocomposites (NCs) (10 wt. % GO) is synthesized via one pot ecofriendly route. It is utilized for photocatalytic degradation of aqueous solution of Malachite green (MG), Crystal violet (CV) and first time mixture of pollutants (CV+MG) dyes in 1 : 2 ratio. These synthesized NCs are analyzed by using many techniques such as P‐XRD, FE‐SEM, HR‐TEM, BET and UV‐Vis spectrophotometer. Kinetics and mechanism of photocatalytic degradation is also explored. The photocatalytic degradation followed the order (CV+MG) (1 : 2) binary system > MG > CV dyes. On the other hand, an antibacterial activity is also investigated against Gram positive (+ve) bacteria such as Staphylococcus aureus (S. aureus), Enterococcus faecalis (E. faecalis) as well as Gram negative (−ve) bacteria such as Escherichia coli (E. coli), and Citrobacter sp. The ZnO/GO NCs followed the antibacterial activity order: E. coli > S. aureus ~ Citrobacter sp. > E. faecalis and the inhibition zones diameters are 20, 15, 15 and 10 mm respectively which is comparable with standard drug Gentamycin.

FABRICATION OF NANOSTRUCTURED IRON AND ZINC PARTICLES BY DIOSPYROS CHLOROXYLON (ROXB.) LEAF EXTRACT: CHARACTERIZATION, ADSORPTION MODELING AND CARCINOGENIC DYE ADSORPTION APPLICATIONS

Objective: The discharge of these synthetic food dyes, such as sunset yellow and tartrazine, into industrial wastewater can lead to significant environmental and health issues. Its removal through effective adsorption presents an economical and efficient solution. Hence this study proposed to fabricate metal nanoparticles for the adsorption of carcinogenic dyes. Methods: The fabrication of iron and zinc nanoparticles employed the green synthesis methodology, utilizing an aqueous extract of Diospyros chloroxylon (Roxb.) as a reducing agent. The fabricated nanoparticles were characterized using TEM (Transmission Electron Microscopy), EDX (Energy-Dispersive X-ray Spectroscopy), SEM (Scanning Electron Microscopy), FTIR (Fourier-Transform Infrared Spectroscopy), and UV-Visible Spectroscopy. The nanoparticles were studied for its efficiency for the adsorption of carcinogenic dyes such as tartrazine and Sunset Yellow. Results: The iron nanoparticles were noticed to be uniformly distributed rod-shaped particles having smooth surfaces with 23-51 nm size range and an average particle size of 34 nm. Whereas the iron nanoparticles were noticed to be uniformly distributed spherical to oval shape with 35 nm to 68 nm size range and an average particle size 53 nm. The XRD results confirm that the iron nanoparticles were rhombohedral phase structure with 71.91 % of elemental iron whereas the zinc nanoparticles were noticed to be hexagonal Wurtzite phase structure having 69.4 % of metallic zinc. These synthesized nanoparticles were applied for the removal of sunset yellow and tartrazine dyes were investigated and found more than 90 % was removed. Adsorption isotherm study was best fitted with Langmuir model, and the maximal adsorption capacity was found to be 52.18 and 75.04 mg/g for sunset yellow using iron and zinc nanoparticles, whereas tartrazine maximum adsorption capacity was noticed to be 69.96 and 84.24 mg/g for iron and zinc nanoparticles. The adsorption reaction follows pseudo-first-order kinetics with high correlation coefficient. Repeated cycles of regeneration, reuse and stability showed very high removal efficiency and stability. Conclusion: The biosynthesis of metal nanoparticles demonstrates substantial promise for applications in environmental protection.

Bimetallic metal-organic frameworks (BMOFs) for dye removal: a review.

Safe drinking water and a clean living environment are essential for good health. However, the extensive and growing use of hazardous chemicals, particularly carcinogenic dyes like methylene blue, methyl orange, rhodamine B, and malachite green, in both domestic and industrial settings, has led to a scarcity of potable water and environmental challenges. This trend poses a serious threat to human society, sustainable global development, and marine ecosystems. Consequently, researchers are exploring more advanced methods beyond traditional wastewater treatment to address the removal or degradation of these toxic dyes. Conventional approaches are often inadequate for effectively removing dyes from industrial wastewater. In this study, we investigated bimetallic metal-organic frameworks (BMOFs) as a solution to these limitations. BMOFs demonstrated outstanding dye removal and degradation capabilities due to their multifunctionality, water stability, large surface area, adjustable pore size, and recyclability. This review provides a comprehensive overview of research on dye removal from wastewater using BMOFs, including their synthesis methods, types of dyes, and processes involved in dye removal, such as degradation and adsorption. Finally, the review discusses the future potential and emerging opportunities for BMOFs in sustainable water treatment.

MWCNT-intercaleated natural hematite-based activable nanocomposite for piezoelectric energy generation and ROS-mediated carcinogenic dye degradation

This work explored an MWCNT-incorporated natural rock-based (hematite) multifunctional piezo-responsive nanocomposite for the simultaneous degradation of carcinogenic dyes and generation of non-invasive energy.

Post-synthetic modification of a covalent organic framework via a thiol–ene reaction for improving fluorescence detection and removal of cationic crystal violet carcinogenic dye

Based on a thiol–ene reaction, a covalent organic framework containing olefins (COF-A) is modified with 2-mercaptoacetic acid to prepare COF-S-COOH for the first time, which greatly improves the sensing and adsorption capacity for crystal violet.

Spectroscopic and computational approaches to investigate the binding mechanism of multi-purpose dye pararosaniline with serum albumin protein

Pararosaniline (PRN) is a significant carcinogenic threat to human, animal, and environmental health and is classified as a Category 2B carcinogen. Investigating the binding interactions of PRN with Bovine Serum Albumin (BSA) is crucial to understand the toxic effects of this carcinogenic dye within the body. This study examined the interaction between PRN and BSA using various spectroscopic techniques and computational methods. Fluorescence spectroscopy was used to determine the thermodynamic parameters required to form the complex and the stability and interactions between them were examined through molecular docking and dynamic simulations. Conformational analysis of the PRN-BSA complex was conducted through Circular Dichroism and Dynamic Light Scattering studies, corroborated by Molecular Dynamics results. The experimental results underscored the dynamic nature of this interaction, showcasing effective binding at physiological temperatures without inducing major conformational alterations in BSA structure. The stability of the complex was attributed to strong hydrophobic interactions with specific amino acid residues in subdomain IB of domain I, as well as notable van der Waals interactions between the dye and water molecules. A detailed energetic assessment of the stable complexation was monitored through MM/PBSA and QM calculations, aligning well with the experimental results. This study provides critical insights into the underlying mechanism of the interaction between PRN and BSA, which can further aid in understanding the toxic effects and potential bioavailability of similar molecules.

Performance of Coconut-shell Activated Carbon on Methylene Blue Treatment

Coconut shell was chosen as a raw material to synthesize activated carbon through physical and chemical activation methods and to evaluate the performance of methylene blue treatment Physical activation method was done by heating the coconut shell in the furnace at 400°C and the chemical activation method was done by using phosphoric acid. Prepared coconut-shell activated carbon (CSAC) was analysed using Fourier-transform infrared spectroscopy (FTIR) to determine the presence of functional groups and their composition. Methylene blue (MB) was chosen as a dye that can be considered as a major pollutant in textile industries’ wastewater. It is a toxic and carcinogenic dye that is harmful to organisms that are exposed to or consumed. The adsorption method using CSAC was used to treat methylene blue due to its higher MB removal efficiency. In this study, methylene blue samples were treated using different dosages of CSAC (15g, 20g, 25g). Color removal (CR%) analysis, COD analysis, and turbidity analysis were done to evaluate the performance of CSAC on methylene blue treatment. 95.59%, 97.40%, and 98.23% of color removal (CR%) were achieved using CSAC dosages of 15g, 20g, and 25g respectively. For COD analysis, 55.41%, 64.33%, and 80.25% of COD removal (%) were achieved when 15g, 20g and 25 g of CSAC dosages were used. 81.48%, 85.19%, and 92.59% of turbidity removal (%) were achieved using CSAC dosages of 15g, 20g, and 25 g respectively. Hence, the adsorption process of MB increases when the dosage of CSAC increases due to surface areas present in the sample.

Hierarchical porous tannic-acid-modified MOFs/alginate particles with synergized adsorption-photocatalysis for water remediation

Organic dye contaminants pose increasing threats to water ecological systems and global sustainability. Rational development of functional particles with adsorption-catalysis synergy is envisioned as a powerful route for enhanced water remediation. Here, hierarchical porous MOF-integrated alginate particles with synergized adsorption and photocatalytic degradation is developed for effective water remediation. The particles exhibit unique mesh-like Ca-alginate (CaAlg) networks with incorporated macro-/micro-porous zeolitic imidazolate framework-8 (ZIF-8) nanoparticles, both modified with negatively-charged tannic acid (TA). The TA-modified mesh-like CaAlg (CaAlg@TA) networks serve as highly porous absorbents, while the TA-modified ZIF-8 (ZIF-8@TA) nanoparticles serve as both hierarchical porous nano-absorbents and photoactive nano-catalysts. This combination simultaneously harnesses the advantages of CaAlg@TA networks and ZIF-8@TA nanoparticles to achieve adsorption-photocatalysis synergy for efficient water remediation. As demonstrated by removal of toxic and carcinogenic dye methylene blue (MB), these particles show much higher performances with fast adsorption and high capacity (1277 mg g−1), as compared to control group particles without adsorption-photocatalysis synergy. Meanwhile, the adsorption-photocatalysis synergy largely suppresses undesired secondary water contamination from the MB-adsorbed particles, and benefits particle regeneration to achieve good reusability for repeated MB removal (>95.5 % for 10 cycles). This work provides a simple and flexible route for rational fabrication of MOF-integrated particles with adsorption-photocatalysis synergy, and thus may open up new horizons for developing advanced functional particles for effective water remediation.

Construction of a reusable Ce-Fe bimetallic oxide flocculant featuring coordinately unsaturated Fe3+ Lewis acid sites for highly efficient and selective removal of Congo Red

Numerous flocculants have been developed to target the removal of Congo Red (CR), a non-degradable and carcinogenic dye. However, challenges such as non-reusability and potential adverse effects limit their widespread application. To address this, a novel cerium oxide-iron (III) oxide (CeO2-Fe2O3, denoted as CeFe) flocculant featuring coordinatively unsaturated Fe3+ Lewis acid sites was synthesized for selective CR removal. Unlike many counterparts, CeFe maintains its efficiency over repeated uses and showcases exceptional stability. The pronounced interaction between CeO2 and Fe2O3 enhances the coordination unsaturation in CeFe, amplifying the electrophilicity of Fe3+ species and creating more Lewis acid sites. According to the results of characterizations and DFT studies, these sites effectively chelate the −NH3 and −N = N − groups on CR molecules, leading to efficient flocculation. Under optimized conditions (pH=6, initial CR concentration of 400 mg/L, and CeFe dosage of 50 mg/L), CeFe achieved a CR removal efficiency of 95.60 ± 0.90%. This research positions CeFe as a promising, reusable flocculant for efficient CR removal, suggesting a new direction in flocculant design.

Propensity of a low-cost adsorbent derived from agricultural wastes to interact with cationic dyes in aqueous solutions.

Ash collected from thrown-away by-products while preparing a popular traditional food additive, kolakhar of the Assamese community of North East, India, was used as an alternate cost-effective, porous bioadsorbent option from the conventional activated carbon for the purification of carcinogenic dyes laden water. The base material for kolakhar preparation was taken from the discarded banana stem waste to stimulate agricultural waste management. Methylene blue (MB) and basic fuchsin (BF) dyes were used as model cationic dyes. Characterization techniques like CHN, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission-scanning electron microscope (FE-SEM), energy dispersive X-ray (EDX), and Brunauer-Emmett-Teller (BET) analysis of the prepared banana stem ash (BSA) reveal the presence of high inorganic contents and functional groups in the irregular, porous bioadsorbent with surface area 55.534 m2g-1. Various regulating parameters studied to optimize the adsorption capacity of BSA were bioadsorbent dose (0.1-3g/L), temperature (298-318K), contact time (0-150min), pH (2-9), and initial dye concentrations (10-40mg/L). Non-linear kinetic models suggested Elovich for both MB and BF adsorption, while the non-linear isotherm model suggested Langmuir and Temkin for MB and BF adsorption, respectively, as best-fitted curves. The monolayer adsorption capacity (qm) for MB and BF was 15.22mg/g and 24.08mg/g at 318K, respectively, with more than 95% removal efficiency for both dyes. The thermodynamic parameters studied indicated that the adsorption is spontaneous. The ∆H0 values of MB and BF adsorptions were 2.303kJ/mol (endothermic) and - 29.238kJ/mol (exothermic), respectively.

Evaluation of azo dyes degradation potential of fungal strains and their role in wastewater treatment

In the present investigation, two fungal strains were exploited to evaluate their degradation capability on Synozol Red, Yellow, and Navy-Blue dyes which gave the utmost decolorization such as 40%, 70%, 90% by Aspergillus niger, and 36%, 73%, 87% by Trichoderma viride, respectively for 60 days. The Gas Chromatography-Mass Spectrometry (GC–MS) analysis of the decolorized dyes suggested that various compounds such as Caprolactam, Furazan-3-carboxamide, oxime, 4-amino-N, N-dimethyl, 6H-Pyrazolo[1,2-a] [1,2,4,5]tetrazine, Hexahydro-2,3-dimethyl, Benzene, 1-propenyl, Dihydroxymaleic acid, Arsenous acid, tris(trimethylsilyl) ester were produced by the fungi which helped in the removal of dyes from the wastewater. The laccase activity of the degraded dyes was proof that both of the strains positively produced the enzyme that helped in the biodegradation of carcinogenic dyes into less harmful products. The A. niger extracted laccase relative activity was 262%, 265%, and 145.7% for Synozol Yellow, Synozol Red, and Navy Blue, respectively. Similarly, laccase, obtained from T. viride, showed relative activity of 187.5% against Synozol Yellow, 215% against Synozol Red, and 202% against Navy Blue. Furthermore, the supernatant extracted from fungi-decolorized wastewater was used to check phytotoxicity on Vigna radiata, which gave excellent results. Both fungal strains, on the basis of their dye degradation potential, can be used to ameliorate wastewater contaminated with azo dyes.

Hydrothermally Synthesized Cu<sub>2</sub>ZnSnS<sub>4</sub> Nanoparticles for Photocatalytic Degradation of Rhodamine B Dye

Industrial dyes contained a wide range of organic compounds that could affect the environment and high dimensional challenges to humans. In recent years, the environmentally safe and inexpensive quaternary copper-based chalcogenide Cu2ZnSnS4 (CZTS) has emerged as a material for photovoltaics and photocatalysis. CZTS nanoparticles were prepared in this investigation using the hydrothermal route at 210 °C for 24 h without the addition of a surfactant or capping agents. Rhodamine B (RhB), a carcinogenic dye, was degraded using the synthesized material through a photocatalytic process. The structural, morphological, optical, and photocatalytic characteristics of CZTS nanoparticles were examined using X-ray diffraction (XRD), Raman spectroscopy, Field emission scanning electron microscopy (FE-SEM), and UV-vis spectroscopy. The average particle size of CZTS is found to be 31 nm with crystalline nature have been characterized by XRD. The results demonstrate that the synthesized sample has mixed morphological structures such as clew-like and flower-like structures and a bandgap of 1.50 eV. CZTS nanoparticles were used as photocatalysts under direct sunlight for Rhodamine B degradation, with the fastest degradation efficiency of 72% at 50 minutes. The results show that surfactant-free hydrothermally synthesized CZTS nanoparticles are a very promising material for the degradation of RhB dye due to the rapid degradation rate and high degradation efficiency.

Unlocking the Potential of N-Doped SnO2 for Sustainable Photocatalytic Degradation of Carcinogenic Dyes

Environmental adulteration is an emerging concern due to the discharge of wastewater effluents from several sources. Several carcinogenic dyes are the major contaminants in these water bodies. These could cause long-lasting and detrimental effects to humans as well as aquatic ecosystems. For efficient degradation of such dyes, the exploration of nanotechnology has demonstrated huge potential. Herein, the degradation of dyes (MB, CV, and MO) has been carried out photocatalytically using N-doped SnO2 nanoparticles (N:SnO2 NPs) as well as in presence of a sacrificial agent, EDTA. These NPs were synthesized at an ambient temperature. Different characterization techniques were used throughout the analysis of the synthesized NPs. The PXRD analysis reveals formation of single-phase rutile structure with tetragonal symmetry. Using the Scherrer formula, the size of the NPs was found to be less than 5 nm, exhibiting increases in size with N doping. Further, morphological analysis through field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) examined the existence of highly agglomerated, spherical NPs. The thermogravimetric analysis (TGA) results depict the thermal stability of the synthesized NPs up to a temperature of 800 °C. These synthesized N:SnO2 NPs exhibit potent efficiency for the photocatalytic degradation of MB, MO, and CV dyes with an efficiency of 93%, 83%, and 73% degradation, respectively, under UV light irradiation. Additionally, the effect of the sacrificial agent, EDTA, was observed on the degradation process and resulted in a degradation of ~90% MB dye, 88% CV dye, and 86% MO dye within 15 min of UV light irradiation.

Comparative evaluation of lipsticks developed using isolated pigments of Capsicum annuum and Lycopersicon esculentum fruits and various natural bases

Cosmetics have lured mankind from time immemorial. Colourant cosmetics have secured a respectable space at the dressing table or salon for their various benefits. Capsicum is widely cultivated across the globe for its pungent principle, capsaicin or capsanthin. However, the bright colour pigments are often neglected due to its pungency. Lycopersicon (tomatoes) also are rich in red colour because of the pigment lycopene. Objective of the current study was to integrate red pigments isolated from capsicum and lycopersicon fruits into lipstick. Major challenge was to nullify the pungency of the capsicum oleoresin. Lipstick bases were formulated using various combinations of waxes and fats. The capsicum oleoresin was treated with NaOH 10 % w/v to nullify the pungency. Lycopene rich extract was obtained from dried tomatoes and later incorporated into the lipsticks bases. The formulated sticks were evaluated and compared against the marketed lipsticks. Our findings reveal that both the lycopene and capsicum oleoresin rich extracts can be conveniently incorporated into the lipsticks and can prove to be a better natural and vegan substitute for synthetic carcinogenic dyes.