Direct C-H Arylation Derived Ternary D-A Conjugated Polymers: Effects of Monomer Geometries, D/A Ratios, and Alkyl Side Chains on Photocatalytic Hydrogen Production and Pollutant Degradation.

Donor-acceptor (D-A) conjugated polymer (CP) featuring high charge mobility and widely tunable energy bands have shown promising prospects in photocatalysis. In this work, a library of ternary D-A CPs (22 polymers) based on benzothiadiazole, bithiophene, and fluorene derivatives (i.e., fluorene [Fl], 9,9-dihexylfluorene [HF], and 9,9'-spirobifluorene [SF]) with and without alkyl side chains, and with 3D geometry are designed and synthesized via atom-economical direct C-H arylation polymerization to explore the synergetic effects of stereochemistry, D/A ratio, and alkyl chains on the properties and photocatalytic performances, which reveal that 1) the cross-shaped 3D spirobifluorene (SF) building block shows the highest hydrogen evolution rates (HER) owing to the sufficient photocatalytic active sites exposed, 2) the alkyl-free linear polymer (FlBtBT0.05 ) exhibit the highest photocatalytic pollutant degradation performance owing to its superior charge separation, and 3) the alkyl side chains are redundances that will exert detrimental effects on the aqueous photocatalysis owing to their insulating and hydrophobic property. The structure-property-performance correlation results obtained will provide a desirable guideline for the rational design of CP-based photocatalysts.

Hydrothermally Grown Globosa-like TiO2 Nanostructures for Effective Photocatalytic Dye Degradation and LPG Sensing.

The rapid expansion of industrial activities has resulted in severe environmental pollution manifested by organic dyes discharged from the food, textile, and leather industries, as well as hazardous gas emissions from various industrial processes. Titanium dioxide (TiO2)-nanostructured materials have emerged as promising candidates for effective photocatalytic dye degradation and gas sensing applications owing to their unique physicochemical properties. This study investigates the development of a photocatalyst and a liquefied petroleum gas (LPG) sensor using hydrothermally synthesized globosa-like TiO2 nanostructures (GTNs). The synthesized GTNs are then evaluated to photocatalytically degrade methylene blue dye, resulting in an outstanding photocatalytic activity of 91% degradation within 160 min under UV light irradiation. Furthermore, these nanostructures are utilized to sense liquefied petroleum gas, which attains a superior sensitivity of 7.3% with high response and recovery times and good reproducibility. This facile and cost-effective hydrothermal method of fabricating TiO2 nanostructures opens a new avenue in photocatalytic dye degradation and gas sensing applications.

A Triazine-Based Analogue of Graphyne: Scalable Synthesis and Applications in Photocatalytic Dye Degradation and Bacterial Inactivation.

Graphyne, a theorized carbon allotrope possessing only sp- and sp2 -hybridized carbon atoms, holds great potentials in many fields, especially in catalysis and energy-transfer/storage devices. Using a bottom-up strategy, we synthesized a new N-doped graphyne analogue, triazine- and 1,4-diethynylbenzene-based graphyne TA-BGY, in solution in gram-scale. The unique sp/sp2 carbon-conjugated TA-BGY possesses an extended porous network structure with a BET surface area of approximately 300 m2 g-1 . Owing to its low optical band gap (1.44 eV), TA-BGY was expected to have many applications, which were exemplified by the photodegradation of methyl orange and photocatalytic bacterial inactivation.

Super porous TiO2 photocatalyst: Tailoring the agglomerate porosity into robust structural mesoporosity with enhanced surface area for efficient remediation of azo dye polluted waste water.

The low surface area of TiO2 (50 m2g-1 - Degussa P25) due to randomly oriented, agglomerated nanostructures and charge carrier recombination tendency, has till date been its major limitation for photocatalytic remediation of polluted wastewater. This study presents an innovative process to design super porous TiO2 nanostructures with high effective surface area (238 m2g-1), robust, structurally ordered mesoporosity via a simple sol-gel assisted reflux method. Detailed material characterization studies suggest that the higher degree of intermolecular ligation in novel templates such as butanetetracarboxylic or tricarballylic acid modified titanium hydroxide gels resulted in retainment of the porous structure during the urea assisted combustion synthesis. The induction of robust structural porosity is accompanied by a reduction in pore size distribution, an increase in pore volume leading to significantly higher total surface area of the synthesized TiO2. Detailed investigation of dye adsorption kinetics and photocatalytic degradation kinetics, complemented by kinetic modeling analysis confirmed that the super porous TiO2 with robust mesoporous structure outperforms the rest of synthesized TiO2 catalyst (having only agglomerate porosity) in terms of its superior adsorption capacity, faster diffusion kinetics and photocatalytic activity for degradation of Amaranth dye. Thus, the super porous TiO2 shows promising potential for application in sustainable photocatalytic technology for remediation of wastewater contaminated with azo dyes.

Valorization of mutant Bacillus licheniformis M09 supernatant for green synthesis of silver nanoparticles: photocatalytic dye degradation, antibacterial activity, and cytotoxicity.

The present study reports the optimization of a green method for the synthesis of silver nanoparticles (AgNPs) via reduction of Ag+ ions using cell-free supernatant of mutant Bacillus licheniformis M09. UV-Visible spectroscopy showing an absorption peak at ~ 430 nm confirmed the synthesis of AgNPs. Transmission electron microscope (TEM) analysis exhibited spherical AgNPs within the size range of 10-30 nm. Fourier transform infrared (FTIR) measurements assured the presence of effective functional molecules which could be responsible for stabilizing the AgNPs. X-ray diffraction (XRD) pattern verified the crystalline nature of AgNPs. Furthermore, the synthesized AgNPs showed an excellent photocatalytic degradation of methylene blue dye in less than 3 h under visible light proving their potential as a catalytic agent for bioremediation for next-generation dye degradation in effluent treatment. The AgNPs demonstrated antimicrobial activity against Gram-positive and Gram-negative foodborne pathogens which endorsed its suitability as agents to extend shelf-life in food packaging and food safety applications. The results also revealed a strong concentration-dependent cytotoxicity of AgNPs against human breast adenocarcinoma cells (MCF-7), while 15.07 µg/mL of IC50 was attained. The outcome suggests the possible application of these AgNPs in nanomedicine formulations. Thus, these findings propose promising ways for the valorization of the waste fermentation supernatant left after cell harvesting and desired metabolite extraction.

A Novel Recyclable Magnetic Nano-Catalyst for Fenton-Photodegradation of Methyl Orange and Imidazole Derivatives Catalytic Synthesis.

A magnetite chlorodeoxycellulose/ferroferric oxide (CDC@Fe3O4) heterogeneous photocatalyst was synthesised via treated and modified cotton in two steps. The designed nanocomposites were characterised by FTIR, TGA, XRD, SEM, and VSM analyses. The Fenton-photocatalytic decomposition efficiency of the synthesised magnetic catalyst was evaluated under visible sunlight using Methyl Orange (MO) as a model organic pollutant. The impacts of several degradation parameters, including the light source, catalyst load, irradiation temperature, oxidant dose, and pH of the dye aqueous solution and its corresponding concentration on the Fenton photodegradation performance, were methodically investigated. The (CDC@Fe3O4) heterogeneous catalyst showed a remarkable MO removal rate of 97.9% at 10 min under visible-light irradiation. (CDC@Fe3O4) nanomaterials were also used in a heterogeneous catalytic optimised protocol for a multicomponent reaction procedure to obtain nine tetra-substituted imidazole derivatives. The green protocol afforded imidazole derivatives in 30 min with good yields (91-97%) at room temperature and under ultrasound irradiation. Generally, a synthesised recyclable heterogeneous nano-catalyst is a good example and is suitable for wastewater treatment and organic synthesis.

Sustainable Utilization of Food Biowaste (Papaya Peel) Extract for Gold Nanoparticle Biosynthesis and Investigation of Its Multi-Functional Potentials.

Papaya contains high amounts of vitamins A, C, riboflavin, thiamine, niacin, ascorbic acid, potassium, and carotenoids. It is confirmed by several studies that all food waste parts such as the fruit peels, seeds, and leaves of papaya are potential sources of phenolic compounds, particularly in the peel. Considering the presence of numerous bioactive compounds in papaya fruit peels, the current study reports a rapid, cheap, and environmentally friendly method for the production of gold nanoparticles (AuNPs) employing food biowaste (vegetable papaya peel extract (VPPE)) and investigated its antioxidant, antidiabetic, tyrosinase inhibition, anti-inflammatory, antibacterial, and photocatalytic degradation potentials. The phytochemical analysis gave positive results for tannins, saponins, steroids, cardiac steroidal glycoside, protein, and carbohydrates. The manufactured VPPE-AuNPs were studied by UV-Vis scan (with surface plasmon resonance of 552 nm), X-ray diffraction analysis (XRD) (with average crystallite size of 44.41 nm as per the Scherrer equation), scanning electron microscopy-energy-dispersive X-ray (SEM-EDS), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), particle size, zeta potential, etc. The mean dimension of the manufactured VPPE-AuNPs is 112.2 d.nm (PDI-0.149) with a -26.1 mV zeta potential. The VPPE-AuNPs displayed a significant antioxidant effect (93.24% DPPH scavenging and 74.23% SOD inhibition at 100 µg/mL); moderate tyrosinase effect (with 30.76%); and substantial α-glucosidase (95.63%) and α-amylase effect (50.66%) at 100 µg/mL. Additionally, it was found to be very proficient in the removal of harmful methyl orange and methylene blue dyes with degradation of 34.70% at 3 h and 24.39% at 5 h, respectively. Taken altogether, the VPPE-AuNPs have been proven to possess multiple biopotential activities, which can be explored by the food, cosmetics, and biomedical industries.

CeO2 nanospheres incorporated with Bi2MoO6/g-C3N4 enhanced photocatalysis towards environmental pollutant Rhodamine B removal.

We have adopted a novel CeO2/Bi2MoO6/g-C3N4-based ternary nanocomposite that was synthesized via hydrothermal technique. The physiochemical characterization of as-prepared samples was examined through various analytical techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy TEM, photoluminescent spectra (PL), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), and ultraviolet diffuse reflectance spectroscopy (UV-DRS) technique. In addition, the photocatalytic performance was carried out by degradation of Rhodamine B dye under visible light irradiation using this nanocatalyst. The ternary nanocomposite achieved 94% of the degradation efficiency within 100 min which is higher than the pristine and binary composites under the predetermined condition pH = 7, Rhodamine B dye = 5 mg/L, and catalyst concentration = 150 mg/L. The experimental synergetic effect of CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite has been ascribed to the interfacial charge carrier migration between CeO2, Bi2MoO6, and g-C3N4. The optical absorption range of CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite was enhanced, and the band gap was reduced up to 2.2 eV. In addition, scavenger trapping experiment proves that the super oxide anions (O2-.) and photogenerated holes are the major active species. The reusability and stability experiment proved the CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite keeps good durability during the photocatalytic degradation process after the five successive cycles. Furthermore, based on the results, the charge carrier transfer photocatalytic mechanism was also discussed. This CeO2/Bi2MoO6/g-C3N4 ternary nanocomposite may offer the cheapest material and extend the great opportunity for clean and environmental remediation approach under the visible light irradiation.

Enhanced photocatalytic activity of V3O7 / V2O5 - reduced graphene oxide nanocomposite towards methylene blue dye degradation.

This work investigates the photocatalytic performance of V2O5 and V3O7 nanoparticles and their nanocomposites with rGO. The as-annealed V2O5 and V3O7 nanoparticles exhibited pure orthorhombic and monoclinic structures with an optical bandgap of 2.3 and 2.5 eV, respectively. The corresponding vibrational modes using Raman and FTIR spectroscopy analysis further confirm the form. The morphological studies reveal that V2O5 and V3O7 nanoparticles possess plate and petal-like morphology, respectively. Moreover, in the case of V2O5/V3O7-rGO nanocomposites, the plate/petal-like nanoparticles are embedded within rGO sheets. Incorporating nanoparticles within rGO sheets has quenched the green photoluminescence emission, enhancing their photocatalytic performance upon irradiation with white light of 100 mW/cm2. This is ascribed to the effective transport of interfacial electrons from vanadium oxide nanoparticles to the rGO surface, reducing the recombination of photogenerated charge carriers. These results indicate that the vanadium oxide/rGO nanocomposites have potential applications in wastewater treatment.

Antioxidant Activities of Photoinduced Phycogenic Silver Nanoparticles and Their Potential Applications.

While various methods exist for synthesizing silver nanoparticles (AgNPs), green synthesis has emerged as a promising approach due to its affordability, sustainability, and suitability for biomedical purposes. However, green synthesis is time-consuming, necessitating the development of efficient and cost-effective techniques to minimize reaction time. Consequently, researchers have turned their attention to photo-driven processes. In this study, we present the photoinduced bioreduction of silver nitrate (AgNO3) to AgNPs using an aqueous extract of Ulva lactuca, an edible green seaweed. The phytochemicals found in the seaweed functioned as both reducing and capping agents, while light served as a catalyst for biosynthesis. We explored the effects of different light intensities and wavelengths, the initial pH of the reaction mixture, and the exposure time on the biosynthesis of AgNPs. Confirmation of AgNP formation was achieved through the observation of a surface plasmon resonance band at 428 nm using an ultraviolet-visible (UV-vis) spectrophotometer. Fourier transform infrared spectroscopy (FTIR) revealed the presence of algae-derived phytochemicals bound to the outer surface of the synthesized AgNPs. Additionally, high-resolution transmission electron microscopy (HRTEM) and atomic force microscopy (AFM) images demonstrated that the NPs possessed a nearly spherical shape, ranging in size from 5 nm to 40 nm. The crystalline nature of the NPs was confirmed by selected area electron diffraction (SAED) and X-ray diffraction (XRD), with Bragg's diffraction pattern revealing peaks at 2θ = 38°, 44°, 64°, and 77°, corresponding to the planes of silver 111, 200, 220, and 311 in the face-centered cubic crystal lattice of metallic silver. Energy-dispersive X-ray spectroscopy (EDX) results exhibited a prominent peak at 3 keV, indicating an Ag elemental configuration. The highly negative zeta potential values provided further confirmation of the stability of AgNPs. Moreover, the reduction kinetics observed via UV-vis spectrophotometry demonstrated superior photocatalytic activity in the degradation of hazardous pollutant dyes, such as rhodamine B, methylene orange, Congo red, acridine orange, and Coomassie brilliant blue G-250. Consequently, our biosynthesized AgNPs hold great potential for various biomedical redox reaction applications.

Single-Step Synthesis of Graphitic Carbon Nitride Nanomaterials by Directly Calcining the Mixture of Urea and Thiourea: Application for Rhodamine B (RhB) Dye Degradation.

Recently, polymeric graphitic carbon nitride (g-C3N4) has been explored as a potential catalytic material for the removal of organic pollutants in wastewater. In this work, graphitic carbon nitride (g-C3N4) photocatalysts were synthesized using mixtures of low-cost, environment-friendly urea and thiourea as precursors by varying calcination temperatures ranging from 500 to 650 °C for 3 h in an air medium. Different analytical methods were used to characterize prepared g-C3N4 samples. The effects of different calcination temperatures on the structural, morphological, optical, and physiochemical properties of g-C3N4 photocatalysts were investigated. The results showed that rhodamine B (RhB) dye removal efficiency of g-C3N4 prepared at a calcination temperature of 600 °C exhibited 94.83% within 180 min visible LED light irradiation. Photocatalytic activity of g-C3N4 was enhanced by calcination at higher temperatures, possibly by increasing crystallinity that ameliorated the separation of photoinduced charge carriers. Thus, controlling the type of precursors and calcination temperatures has a great impact on the photocatalytic performance of g-C3N4 towards the photodegradation of RhB dye. This investigation provides useful information about the synthesis of novel polymeric g-C3N4 photocatalysts using a mixture of two different environmentally benign precursors at high calcination temperatures for the photodegradation of organic pollutants.

GQD@NiFe-LDH Nanosheets for Photocatalytic Activity towards Textile Dye Degradation via Lattice Contraction.

The functionalized NiFe-LDH with photosensitized GQDs were synthesized through the hydrothermal route by differing the amount of GQDs solution and studied its efficacy towards the mineralization of textile dyes under visible light. The synthesized samples were characterized by XRD, FESEM, HRTEM, DRUV-Vis, RAMAN, XPS, and BET. The combined effect of the hexagonal carbon lattice in GQD and open layered porous structure of NiFe-LDH nanosheets results in the contraction of the lattice. Different reactive and conventional dyes were taken as representative dyes to evaluate the activity of the as-synthesized photocatalysts. The enhanced electron absorption/donor effect between GQDs and NiFe-LDH, and the growth of oxygen-bridged Ni/Fe-C moieties enable the composite to exhibit better photocatalytic activity. Both photocatalytic activity and characterization results confirmed that the GQD@NiFe-LDH nanocomposite heterostructure synthesized at 160 °C by taking 10 mL of GQDs aqueous solution named GNFLDH10 has a higher degree of crystallinity and has the best photocatalytic efficiency compared to other reported visible light catalysts. Specifically, the above optimized GQD@NiFe-LDH photocatalyst is capable of photo-mineralizing 50 ppm of Reactive Green in 20 min, Reactive Red in 20 min, and Congo Red in 25 min respectively following a direct Z-scheme mechanism with substantial reusability.

Porous Ag3VO4/KIT-6 composite: Synthesis, characterization and enhanced photocatalytic performance for degradation of Congo Red.

Novel Ag3VO4/KIT-6 nanocomposite photocatalyst has been successfully fabricated by a newly-designed simple hard-template induction process, in which the particles of Ag3VO4 were grown on the KIT-6 surface and inside the porous framework of the silica matrix. The developed porous framework nanocomposite was characterized by several techniques including N2-Physiosorption analysis. The obtained nanocomposite revealed a high surface area (273.86 m2/g) along with the possession of monoclinic Ag3VO4, which is highly responsive to visible light (with distinct intensity at about 700 nm). The UV-Vis DRS reveals that the Ag3VO4/KIT-6 photocatalyst bears a bandgap of 2.29 eV which confirms that the material has a good visible light response. The synthesized nanocomposite was tested for its superior physicochemical properties by evaluating its degradation efficiency for Congo Red (CR). The novel composite exhibited superior degradation capability of CR, reaching up to 96.49%, which was around three times the pure Ag3VO4. The detailed kinetic study revealed that the as-prepared material followed a pseudo first order kinetic model for the CR degradation. The study includes a comprehensive parametric study for the formulation of the optimized reaction conditions for photocatalytic reactions. The commercial applicability of the composite material was investigated by a regeneration and recyclability test, which revealed extraordinary results. Furthermore, the possible degradation pathway for CR was also proposed.

Biologically Synthesized Silver Nanoparticles and Their Diverse Applications.

Nanotechnology has become the most effective and rapidly developing field in the area of material science, and silver nanoparticles (AgNPs) are of leading interest because of their smaller size, larger surface area, and multiple applications. The use of plant sources as reducing agents in the fabrication of silver nanoparticles is most attractive due to the cheaper and less time-consuming process for synthesis. Furthermore, the tremendous attention of AgNPs in scientific fields is due to their multiple biomedical applications such as antibacterial, anticancer, and anti-inflammatory activities, and they could be used for clean environment applications. In this review, we briefly describe the types of nanoparticle syntheses and various applications of AgNPs, including antibacterial, anticancer, and larvicidal applications and photocatalytic dye degradation. It will be helpful to the extent of a better understanding of the studies of biological synthesis of AgNPs and their multiple uses.

Photocatalytic dye degradation using nickel ferrite spinel and its nanocomposite.

Coloured wastewater is a major issue of today for human health and ecology. Among all available processes such as physical, chemical, biological and electrochemical methods, photocatalysis can be a promising solution because of its ability to degrade colour-causing compounds completely by converting them into simpler molecules (H2O, CO2) depending on dye structure. In this work, NiFe2O4 was synthesized by the co-precipitation method. Furthermore, the composites of NiFe2O4 with TiO2 were synthesized by varying amounts of TiO2. The spinel and composites were characterized by XRD, ZETA analysis and UV-DRS. Their photocatalytic activities were investigated using the photocatalytic degradation of reactive turquoise blue 21 (RB 21) dye as model pollutants under sunlight. The increased absorption of the visible light and the enhanced separation of the electron-hole pairs due to the relative energy band positions in NiFe2O4 and TiO2 are considered as the main advantages. Our results showed that NiFe2O4-based nanocomposites could be used as an effective and magnetic retrievable photocatalyst.

Fabrication of novel magnetic CuS/Fe3O4/GO nanocomposite for organic pollutant degradation under visible light irradiation.

The magnetic nanocomposites composed of copper sulphide, iron oxide, and graphene oxide (CuS/Fe3O4/GO) were synthesized through a facile sol-gel combined with hydrothermal techniques for photodegradation of methylene blue (MB) as a model organic pollutant. The as-prepared samples were characterized by powder X-ray diffraction (XRD), vibrating sample magnetometer (VSM), differential reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray analysis (EDX) and results confirmed successful synthesis of magnetic nanocomposite. Presence of Fe3O4 and GO in nanocomposite induced a synergistic effect in CuS performance as CS88F6G6 (i.e. 88% CuS, 6% Fe3O4, and 6% GO). The photocatalytic degradation efficiency of MB reached up to 90.3% after exposure to visible light irradiation for 80 min. The composite nanosheets are photostable, reusable, and magnetically recoverable, revealing potential application in removal of organic pollutants.

Microbial Fabrication of Zinc Oxide Nanoparticles and Evaluation of Their Antimicrobial and Photocatalytic Properties.

Zinc oxide (ZnO) nanoparticles have attracted significant interest in a number of applications ranging from electronics to biomedical sciences due to their large exaction binding energy (60 meV) and wide bandgap of 3.37 eV. In the present study, we report the low-cost bacterium based "eco-friendly" efficient synthesis of ZnO nanoparticles by using the zinc-tolerant bacteria Serratia nematodiphila. The physicochemical characterization of ZnO nanoparticles was performed by employing UV-vis spectroscopy, XRD, TEM, DLS, Zeta potential, and Raman spectroscopy. The antimicrobial and antifungal studies were investigated at different concentrations using the agar well-diffusion method, whereby the microbial growth rate decreases with the increase in nanoparticle concentration. Further, photocatalytic performance studies were conducted by taking methyl orange (MO) as a reference dye.

Modeling and optimization of Photocatalytic Decolorization of binary dye solution using graphite electrode modified with Graphene oxide and TiO2.

In this paper, the experimental design methodology was employed for modeling and optimizing the operational parameters of the photocatalytic degradation of a binary dye solution using a fixed photocatalytic compound. The compound used was modified graphite electrode (GE) with graphene oxide (GO) on which TiO2 nanoparticles were immobilized. GO nanoparticle was deposited on graphite electrode (GO-GE) using electrochemical approach. TiO2 nanoparticles were immobilized on GO-GE by solvent evaporation method. A binary solution containing mixture of methylene blue (MB) and acid red 14 (AR14) was chosen as dye model. The degradation intermediates were detected and analyzed using gas chromatography. Effect of different factors on the photocatalytic decolorization efficiency was investigated and optimized using response surface methodology (RSM). The obtained results indicated that the prepared TiO2-GO-CE can decolorize MB with high efficiency (93.43%) at pH 11, dye concentration of 10 mg/L and 0.04 g of immobilized TiO2 on the GO fabricated plates after 120 min of photocatalytic process. It was demonstrated that by modifying GE with GO the stability of the electrode was remarkably enhanced. The ANOVA results (R2 = 0.97 and P value <0.0001 for MB, R2 = 0.96 and P value <0.0001 for AR14) and numerical optimization showed that it is possible to make good prediction on decoloration behavior and save time and energy with less number of experiments using design of experiments (DoE) like the RSM. Graphical abstract Wastewater treatment processWastewater treatment process.

In-situ synthesis of rGO-ZnO nanocomposite for demonstration of sunlight driven enhanced photocatalytic and self-cleaning of organic dyes and tea stains of cotton fabrics.

Recently, research activities are focused on development of 2D reduced graphene oxide (rGO) based semiconductor nanocomposite materials for boosting up its catalytic applications. In this work, a rarely reported green synthesis approach has been envisioned to synthesize in-situ 2D rGO-ZnO (rGZn) nanocomposites from Apple juice and zinc acetate. Also the composition of the samples has been optimized to achieve high photocatalytic and self-cleaning properties by the formation of reactive oxidation species. The samples are characterized for their microstructural, optical absorption and photoluminescence properties. It has been tested that rGZn nanocomposites are capable of removing a test dye, namely methylene blue (MB) from water and achieved the highest dye degradation efficiency of ∼91% within only 60 min under UV-vis light irradiation. A smart cotton fabric (CF) coated with rGZn has been prepared and demonstrated its photocatalytic self-cleaning property by degradation of MB, rhodamine B dyes and tea stains on it even under sunlight irradiation, which is scarcely available in the literature. Therefore, this work may open a new avenue of research for low cost and easy synthesis of rGO-semiconductor nanocomposites with high photocatalytic properties for industrial applications as well as for development of rGO based smart fabric for real-life applications.

Photocatalytic and antibacterial activity of cadmium sulphide/zinc oxide nanocomposite with varied morphology.

Nanocomposites with multifunctional application prospects have already dragged accelerating interests of materials scientists. Here we present CdS/ZnO nanocomposites with different morphology engineering the precursor molar ratio in a facile wet chemical synthesis route. The materials were structurally and morphologically characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX) and high-resolution transmission electron microscopy (HRTEM). The growth mechanism of the composite structure with varying molar ratio is delineated with oriented attachment self assemble techniques. Photocatalytic activity of CdS/ZnO nanocomposites with varying morphology were explored for the degradation of rhodamine B (RhB) dye in presence of visible light irradiation and the results reveal that the best catalytic performance arises in CdS/ZnO composite with 1: 1 ratio. The antibacterial efficiency of all nanocomposites were investigated on Escherichia coli, Staphylococcus aureus and Klebsiella pneumonia without light irradiation. Antibacterial activity of CdS/ZnO nanocomposites were studied using the bacteriological test-well diffusion agar method and results showed significant antibacterial activity in CdS/ZnO composite with 1:3 ratio. Overall, CdS/ZnO nanocomposites excel in different potential applications, such as visible light photocatalysis and antimicrobial activity with their tuneable structure.