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This paper reports the photoluminescence and nonlinear optical (NLO) properties of Ce2O3–TiO2 nanocomposites synthesized via sol–gel process with different concentrations of cerium. The physical characterization studies by means of XRD indicated for the successful incorporation of Ce into the lattice of TiO2, while the UV-visible spectra for an absorption edge shift of TiO2 to the higher wavelength side following the Ce addition, and FESEM analysis for the morphology and particles sizes of the synthesized materials. On testing of the photoluminescence properties recorded through time-resolved fluorescence (TCSPC) technique, a decrease in the intensity of TiO2 with that of increased Ce concentration was observed and is due to an escalation in the number of oxygen vacancies. Further, the observation NLO properties for Ce2O3–TiO2 was done by a Z-scan technique of 5ns continuous wave (cw) laser at 532 nm, where the involvement of active mechanisms in the nonlinear refraction and nonlinear absorption are due to the saturable absorption (SA) and nonlinear thermal effects.

Herein, we report a facile hydrothermal synthesis of MnO2 nanoparticles anchored multi walled carbon nanotubes (MnO2@MWCNTs) as potential anode materials for lithium-ion (Li-ion) batteries. The prepared MnO2@MWCNTs were characterized by several techniques which confirmed the formation of MnO2 nanoparticles anchored MWCNTs. The X-ray diffraction and Raman-scattering analyses of the prepared material further revealed the effective synthesis of MnO2@MWCNTs. The fabricated Li-ion battery based on MnO2@MWCNTs exhibited a reversible capacity of ~823 mAhg−1 at a current density of 100 mAg−1 for the first cycle, and delivered a capacity of ~421 mAhg−1 for the 60 cycles. The coulombic efficiency was found to be ~100% which showed excellent reversible charge–discharge behavior. The outstanding performance of the MnO2@MWCNTs anode for the Li-ion battery can be attributed to the distinctive morphology of the MnO2 nanoparticles anchored MWCNTs that facilitated the fast transport of lithium ions and electrons and accommodated a broad volume change during the cycles of charge/discharge.

Root like structured Ni-doped zinc oxide [Zn(1-x)NixO (x = 0.09)] thin films were deposited on a non-conducting glass substrate by indigenously developed spray pyrolysis system at optimized substrate hotness of 573±5 K. Thus obtained Ni-doped ZnO thin films were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Atomic Force Microscopy (AFM). XRD result revealed that Ni-doped ZnO has a polycrystalline nature with a hexagonal wurtzite structure. For pure ZnO and Ni-doped ZnO thin films, the particle sizes were 60.9 and 53.3 nm while lattice strain values were 1.56×10−3 and 1.14×10−3, respectively. The film surface showed characteristic root-like structure as observed by the SEM. It was observed that the Ni-doped ZnO thin films were grown in high density along with more extent of branching as compared to pure ZnO thin films but retained the root-like morphologies, however, the branches were more-thinner and of shorter lengths. AFM analysis showed that the surface grains of the Ni-doped samples are homogeneous with less RMS roughness values compared with the undoped ZnO samples. The photocatalytic activity of the prepared thin films was evaluated by the degradation of methyl orange (MO) dye under UV light irradiation. Pure ZnO and Ni-doped ZnO thin films took 150 min and 100 min to degrade about 60% MO dye, respectively.

Photocatalysts provide excellent potential for the full removal of organic chemical pollutants as an environmentally friendly technology. It has been noted that under UV-visible light irradiation, nanostructured semiconductor metal oxides photocatalysts can degrade different organic pollutants. The Sn6SiO8/rGO nanocomposite was synthesized by a hydrothermal method. The Sn6SiO8 nanoparticles hexagonal phase was confirmed by XRD and functional groups were analyzed by FT-IR spectroscopy. The bandgap of Sn6SiO8 nanoparticles (NPs) and Sn6SiO8/GO composites were found to be 2.7 eV and 2.5 eV, respectively. SEM images of samples showed that the flakes like morphology. This Sn6SiO8/rGO nanocomposite was testing for photocatalytic dye degradation of MG under visible light illumination and excellent response for the catalysts. The enhancement of photocatalytic performance was mainly attributed to the increased light absorption, charge separation efficiency and specific surface area, proved by UV-vis DRS. Further, the radical trapping experiments revealed that holes (h+) and superoxide radicals (·O−2) were the main active species for the degradation of MG, and a possible photocatalytic mechanism was discussed.

Herein, we report the facile synthesis, characterization and visible-light-driven photocatalytic degradation of perforated curly Zn0.1Ni0.9O nanosheets synthesized by hydrothermal process. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies confirmed the cubic phase crystalline structure and growth of high density perforated curly Zn0.1Ni0.9O nanosheets, respectively. As a photocatalyst, using methylene blue (MB) as model pollutant, the synthesized nanosheets demonstrated a high degradation efficiency of ~76% in 60 min under visible light irradiation. The observed results suggest that the synthesized Zn0.1Ni0.9O nanosheets are attractive photocatalysts for the degradation of toxic organic waste in the water under visible light.

Herein, we report the effect of synthesis temperature on the morphologies, optical and electronic properties of magnesium oxide (MgO) nanostructures. The MgO nanostructures were synthesized at different temperatures, i.e., 100 °C, 300 °C, and 600 °C by simple chemical reaction process and their morphology, particle size, optical, and electrical properties were examined by different techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and UV-Vis. spectroscopy. The morphological investigations revealed that various morphologies of MgO nanostructures, i.e., nanoparticles, nanosheet networks, and nanoneedles were synthesized at 100 °C, 300 °C, and 600 °C. The XRD results confirmed that with increasing the synthesis temperature, the crystallinity of the synthesized nanostructures increases. Further, the dielectric properties and AC conductivity at various frequencies for MgO nanostructures were studied which revealed that the dielectric losses decrease with increase in frequency and temperature. In addition, the observed band gap decreases from 4.89 eV to 4.438 eV (100 °C to 600 °C) representing its increase in the conductivity.

Herein, we report the facile microwave-assisted synthesis, characterization and photocatalytic degradation applications of Bismuth ferrite heterostructures composed of interconnected nanosheets (BHNs). The synthesized materials were subjected to several analytical studies such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy and UV-visible spectroscopy in order to examine the morphological, structural, optical and photo catalytic properties. The structural and morphological characterizations confirmed the rhombohedral perovskite crystal structure and the formation of heterostructures composed of interconnected nanosheets for the synthesized material. The compositional characterization revealed that the synthesized material is bismuth ferrite with high purity. The BHNs were further used as efficient photocatalyst for the photocatalytic degradation of highly hazardous pollutant methyl orange under sunlight irradiation. The sunlight driven photocatalytic experiments revealed ~86% photodegradation of methyl orange dye in 150 min. The presented work revealed that the synthesized BHNs are excellent material for the photocatalytic degradation of various organic contaminants and hazardous pollutants.

Herein, we report a simple synthesis, characterization and photocatalytic degradation application of composite NiO-WO₃ nanoparticles. The nanoparticles were synthesized by facile low-temperature method and characterized by several techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis diffuse reflectance spectra (DRS). The synthesized NiO-WO₃ nanoparticles were used as efficient photocatalyst for the photocatalytic degradation of Eosin yellow (EY) dye. Interestingly, the synthesized photocatalytic exhibited a significant visible-light driven photocatalytic degradation of Eosin yellow (EY) dye. Under optimized conditions (pH = 5, catalyst dosage = 3 μM and initial dye concentration= 1.0 g/L), the obtained photo degradation of EY dye was above 95% in 180 min under visible light irradiation. Remarkably, reusability of the prepared photocatalyst was also observed and the photo-degradation reactions follow the pseudo-first-order model.

Herein, we report the facile synthesis of Iron oxide@Pt core-shell nanoparticles (NPs) by facile two step synthesis process. The first step follows the growth of iron oxide nanoparticle by thermal decomposition process while the second step deals with the formation of iron oxide@Pt core-shell nanoparticles by the chemical reduction method. The synthesized core-shell nanoparticles were characterized by several techniques and used for the catalytic reductive translation of Cr(VI) to Cr(III) in the presence of formic acid by a UV-vis spectrophotometer. The UV photo-spectrometer analysis confirmed the conversion efficiency from 12% to as high as 98.8% at the end of 30 minutes. Thus, the presence of Iron oxide @Pt core-shell nanoparticles (NPs) can be effectively used as a catalyst for the reducion of Cr(VI) to Cr(III) ions. Additionally, antibacterial studies were performed for the prepared core-shell nanoparticles against two bacterial strains, i.e., gram (+ve) Staphylococcus Aureus (S. Aureus) and gram (-ve) Escherichia Coli (E. Coli).

This study reports the biosynthesis of silver nanoparticles (AgNPs) using methanolic leaf extract of Pogostemon cablin Benth. (Patchouli) as a reducing agent, and their potent biological (antibacterial, antioxidant and anticancer) activities. The P. cablin extract when exposed to silver nitrate reduced silver ions to form crystalline AgNPs within 1 h of incubation at room-temperature. UV-visible spectra showed a sharp surface plasmon resonance (SPR) at around 430 nm for the biosynthesized AgNPs and the XRD pattern indicated the crystalline planes of the face centered cubic silver. The FE-SEM analysis revealed the occurrence of predominant spherical shaped AgNPs with a huge disparity in their particle size distribution with an average size of 25 nm, while, the FTIR data confirmed the bio-reduction and capping of AgNPs by several phytocompounds present in the methanolic leaf extract. AgNPs effectively inhibited the growth of all the tested human pathogenic bacterial strains (Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli), while, the methanolic leaf extract failed to inhibit the growth of S. aureus and P. aeruginosa. AgNPs showed the highest free radical scavenging activity (79.0 ± 0.76%) compared to methanolic leaf extract (68.3 ± 0.68%) at 100 μg/ml. Further, the cytotoxicity study using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) confirmed that AgNPs successfully inhibited the human colon adenocarcinoma cell line (HT-29) in a dose dependent manner. At higher concentrations (500 μg/ml), only 4% of cells survived after 72 hrs of exposure with IC50 value of 120 μg/ml. Thus, these findings offer a new source of biomolecules with diverse biological activities.

Herein, we report the synthesis, characterization and picric acid chemical sensing application of samarium (Sm) doped ZnO nanorods. The Sm-doped ZnO nanorods were synthesized by facile hydrothermal process and characterized using various analytical methods which confirmed the large-scale synthesis and wurtzite hexagonal crystal structure for the synthesized nanorods. The doping of Sm ions in the lattices of the synthesized nanorods was evaluated by the energy dispersive X-ray spectroscopy (EDS). The synthesized Sm-doped ZnO nanorods were used as potential scaffold to fabricate high sensitive and reproducible picric acid chemical sensor based on I–V technique. The fabricated picric acid chemical sensor based on Sm-doped ZnO nanorods exhibited a high sensitivity of 213.9 mA mM−1 cm−2 with the limit of detection of ∼0.228 mM and correlation coefficient of R═0.9889. The obtained results revealed that the facile grown Sm-doped ZnO nanorods can efficiently be used to fabricate high sensitive and reproducible chemical sensors.

B, N-codoped titania mesoporous crystals were prepared by the sol-gel method followed by a molten nitrate process to modify the sample morphology. The composition, morphology and microstructure of the obtained samples were characterized by X-ray diffraction (XRD), X-ray photoemission spectroscope (XPS), Brunauer Emmett Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). Fourier Transform Infrared spectroscopy (FTIR) revealed weak complex vibrations between the Ti-O oxide species and the unsaturated sites (Ti3+) through the incorporation of hydroxyl groups, which was not observed in the bulk titania (B-N-TiO₂). The photocatalytic reactivity of boron-nitrogen codoped TiO₂ was examined for the removal of methylene blue (MB) under visible light irradiation. The nitrates treated B-doped TiO₂ exhibited better photocatalytic activity for dye degradation than that of B-doped TiO₂ and nitrates treated TiO₂. The best performance was obtained in the sample treated at a calcination temperature of 550 °C.

Hydroxyapatite (HA) nanocoating was electrodeposited on the surface mechanical attrition treated (SMATed) AZ31 magnesium alloy. Phases, morphologies and the adhesion of coating were characterized by X-ray diffraction, scanning electron microscopy (SEM) and 3D optical profiler. The corrosion resistance of the HA coating was tested by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed that the HA coating on SMATed sample had a better crystallization than that on original one. The thickness of HA coating increased from 25 to 40 μm. The bonding strength between HA coating and SMATed substrate was higher than that between the coating and untreated counterpart. Potentiodynamic polarization and EIS demonstrated that the corrosion current density of HA coating on SMATed substrate decreased by 30.84% than that on original. The corrosion potential shifted 80.3 mV to the positive direction. The corrosion resistance of coatings on SMATed sample was significantly enhanced. The immersion experiments showed that the HA coatings on SMATed sample exhibited a better biological activity.

This paper reports the photoluminescence and nonlinear optical (NLO) properties of Ce₂O₃-TiO₂ nanocomposites synthesized via sol-gel process with different concentrations of cerium. The physical characterization studies by means of XRD indicated for the successful incorporation of Ce into the lattice of TiO₂, while the UV-visible spectra for an absorption edge shift of TiO₂ to the higher wavelength side following the Ce addition, and FESEM analysis for the morphology and particles sizes of the synthesized materials. On testing of the photoluminescence properties recorded through time-resolved fluorescence (TCSPC) technique, a decrease in the intensity of TiO₂ with that of increased Ce concentration was observed and is due to an escalation in the number of oxygen vacancies. Further, the observation NLO properties for Ce₂O₃-TiO₂ was done by a

Herein, we report a facile hydrothermal synthesis of MnO₂ nanoparticles anchored multi walled carbon nanotubes (MnO₂@MWCNTs) as potential anode materials for lithium-ion (Li-ion) batteries. The prepared MnO₂@MWCNTs were characterized by several techniques which confirmed the formation of MnO₂ nanoparticles anchored MWCNTs. The X-ray diffraction and Raman-scattering analyses of the prepared material further revealed the effective synthesis of MnO₂@MWCNTs. The fabricated Li-ion battery based on MnO₂@MWCNTs exhibited a reversible capacity of ~823 mAhg

Photocatalysts provide excellent potential for the full removal of organic chemical pollutants as an environmentally friendly technology. It has been noted that under UV-visible light irradiation, nanostructured semiconductor metal oxides photocatalysts can degrade different organic pollutants. The Sn

Herein, we report the facile synthesis, characterization and visible-light-driven photocatalytic degradation of perforated curly Zn

Nanostructure materials are of interest in last few decades due to their unique size-dependent physio-chemical properties. In this paper, zinc oxide (ZnO) and barium doped ZnO nanodisks (NDs) were synthesized using sonochemical method and characterized by various techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), UV-vis absorption and dielectric measurements. The XRD and FTIR studies confirm the crystalline nature of ZnO NDs, and the average crystallite size was found to be ~25 nm for pure ZnO and ~22 nm for Ba doped ZnO NDs. SEM study confirmed the spherical shaped ZnO NDs with average sizes in the range of 20–30 nm. The maximum absorbance was obtained in the 200–500 nm regions with a prominent peak absorbance were observed by UV-vis spectra. The corresponding band gap for ZnO NDs and Ba doped ZnO NDs were calculated using Tauc’s plot and was found to be 3.12 and 3.04, respectively. The conductivity and dielectric measurements as a function of frequency have been studied.

Zn

Poly(ethylene terephthalate) (PET) is a versatile engineering plastic which exhibits exceptional mechanical and thermal properties. Huge amounts of PET are consumed in various industries such as food packaging industry, textile industry, in the manufacturing of audio, video tapes and X-ray films and so on. But due to its substantial fraction by volume in water bodies and its high persistence to the atmospheric and biological agents, it could be considered as a hazard substance. Thereby chemical recycling of PET serves as a solution to solid waste problem as it transforms PET into its monomers via hydrolysis. Chemical recycling of post consumed waste PET bottles via alkaline hydrolysis is the main aim of this paper. Operating parameters such as reaction time and temperature were optimized for the conversion of PET into nanospindle-shaped terephthalic acid (TPA). Depolymerization of PET was carried out via alkaline hydrolysis by varying reaction time and temperature and maximum yield of 92% was obtained at 200 °C with reaction time of 25 minutes. The formed TPA nanospindles were further characterized in detail which exhibited high crystallinity, purity and fascinating thermal and surface properties.

Herein, we report a facile synthesis, characterization and dye sensitized solar cell (DSSC) application of flower-shaped ZnO nanostructures. The flower-shaped ZnO nanostructures were synthesized by low-temperature hydrothermal process and characterized in detail by several techniques. The detailed morphological studies confirmed that the flower-shaped structures are formed by the accumulation of several nanoneedles which are axially arranged through their bases in a special fashion that they made flower-like morphologies. The compositional, structural and optical characterizations revealed that the synthesized flowers possess high purity, well-crystallinity with the wurtzite hexagonal phase and good optical properties. The synthesized flower-shaped ZnO nanostructures were used as photoanode to fabricate DSSC which attained a reasonable solar to electrical conversion efficiency of ~1.1%, open-circuit current (VOC) of 0.611 V, short circuit current (JSC) of 3.53 mA/cm2 and fill factor (FF) of 0.51.

Herein, we report the facile synthesis of high-aspect ratio perforated Co3O4 nanowires derived from cobalt-carbonate-hydroxide (Co(CO3)0.5(OH) 0.11H2O) nanowires. The Co(CO3)0.5(OH) 0.11H2O nanowires were synthesized by simple hydrothermal process at 120 °C while annealing of such nanowires at 400 °C leads the formation of perforated Co3O4 nanowires. The prepared nanowires were characterized by several techniques which confirmed the high aspect ratio and well-crystallinity for the synthesized nanowires. For application point of view, the prepared perforated Co3O4 nanowires were used as efficient electrode material to fabricate highly sensitive and selective hydrazine chemical sensor. The electrochemical impedance spectroscopy (EIS) technique was employed to confirm the successful modification of the electrode. The key parameters of chemical sensor, such as detection limit, sensitivity, and linear range, have been systematically explored. The fabricated hydrazine sensor displayed a rather low detection limit of 4.52 μM (S/N = 3), a good sensitivity of 25.70 μA · mM-1, and a wide linear range of 16.97-358.34 μM.

In this work, partially exfoliated multi-walled carbon nanotubes (Px-CNTs) were prepared by oxidizing multi-walled carbon nanotubes (MWCNTs) and applied into water-based lubricant as a kind of new additives, resulting in an outstanding anti-friction effect. The Px-CNTs have the structures of both MWCNTs and graphene oxide nanoribbons (GONRs). The special structure could prevent aggregation in water-based lubricant and reduce friction effectively. At the same time, Px-CNTs generate both sliding and rolling friction like MWCNTs and GONRs simultaneously. The friction force of Px-CNTs tended to go up after declining with increasing its loading, suggesting the existence of optimum additive amount of additions. Compared with water, water with 0.5 wt% Px-CNTs further reduced the friction force up to 66.4%. Compared with CNTs-COOH and GONRs dispersed in water via a similar method, Px-CNTs in water displays remarkable friction characteristic, suggesting that the friction force of water with 0.5 wt% Px-CNTs is decreased by 19.82% and 13.82% compared with water with 0.3 wt% MWCNTs and GONRs.

Nanobiotechnology has emerged as a promising technology to develop new therapeutically active nanomaterials. The present study was aimed to biosynthesize AgNPs extracellularly using Aspergillus niger JX556221 fungal extract and to evaluate their anticancer potential against colon cancer cell line, HT-29. UV-visible spectral characterization of the synthesized AgNPs showed higher absorption peak at 440 nm wavelength. Transmission Electron Microscopy (TEM) analysis revealed the monodispersed nature of synthesized AgNPs occurring in spherical shape with a size in the range of 20-25 nm. Further, characterization using Energy Dispersive Spectroscopy (EDX) confirmed the face-centred cubic crystalline structure of metallic AgNPs. FTIR data revealed the occurrence of various phytochemicals in the cell free fungal extract which substantiated the fungal extract mediated AgNPs synthesis. The cytotoxic effect of AgNPs was studied by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results evidenced the cytotoxic effect of AgNPs on HT-29 cell lines in a dose dependent manner. The highest activity was found at 100 μg/ml concentration after 24 h of incubation. Use of propidium iodide staining examination method confirmed the cytotoxic effect of AgNPs through inducing cell apoptosis. AgNPs cytotoxicity was found to be through elevating reactive oxygen species (ROS), and caspase-3 activation resulting in induced apoptosis. Therefore, this research finding provides an insight towards the development of novel anticancer agents using biological sources.

In this paper, we report the synthesis, characterization and ethanol sensing applications of CuO nanoparticles. The CuO nanoparticles were prepared by a facile, low-temperature hydrothermal method and characterized in detail in terms of their structural, morphological, compositional and crystalline properties, through different characterization techniques including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) attached with energy dispersive spectroscopy (EDS), and Fourier transform infrared (FTIR) spectroscopy. The detailed studies revealed that the synthesized CuO nanoparticles were well-crystalline and possessed monoclinic crystal structure. The synthesized CuO nanoparticles were utilized for the fabrication of highly sensitive ethanol gas sensor. At an optimized temperature of 320 °C, high sensitivity (Ra/Rg) of 39.29 was observed for 200 ppm of ethanol gas. Additionally, very low response (τres = 14 s) and recovery (τrec = 30 s) times were observed for 100 ppm of ethanol.

Herein, we report the growth and characterizations of well-crystalline n-ZnO nanowires assembled in micro flower-shaped morphologies. The nanowires are grown on p-Silicon substrate and characterized in terms of their structural, morphological and electrical properties. Temperature dependent transport characteristics of the fabricated n-ZnO/p-Si heterojunction diode were examined. The morphological studies revealed that the nanowires are grown in high-density and arrange in special micro flower shaped morphology. The structural characterizations confirmed that the nanowires are well-crystalline and possessing wurtzite hexagonal phase. The electrical properties were evaluated by examining the I–V characteristics of the fabricated n-ZnO/p-Si heterojunction diode. The I–V characteristics were studied at temperature

Herein, we report the facile microwave-assisted synthesis, characterization and photocatalytic degradation applications of Bismuth ferrite heterostructures composed of interconnected nanosheets (BHNs). The synthesized materials were subjected to several analytical studies such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy and UV-visible spectroscopy in order to examine the morphological, structural, optical and photo catalytic properties. The structural and morphological characterizations confirmed the rhombohedral perovskite crystal structure and the formation of heterostructures composed of interconnected nanosheets for the synthesized material. The compositional characterization revealed that the synthesized material is bismuth ferrite with high purity. The BHNs were further used as efficient photocatalyst for the photocatalytic degradation of highly hazardous pollutant methyl orange under sunlight irradiation. The sunlight driven photocatalytic experiments revealed ~86% photodegradation of methyl orange dye in 150 min. The presented work revealed that the synthesized BHNs are excellent material for the photocatalytic degradation of various organic contaminants and hazardous pollutants.

Herein, we report a simple synthesis, characterization and photocatalytic degradation application of composite NiO-WO₃ nanoparticles. The nanoparticles were synthesized by facile low-temperature method and characterized by several techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis diffuse reflectance spectra (DRS). The synthesized NiO-WO₃ nanoparticles were used as efficient photocatalyst for the photocatalytic degradation of Eosin yellow (EY) dye. Interestingly, the synthesized photocatalytic exhibited a significant visible-light driven photocatalytic degradation of Eosin yellow (EY) dye. Under optimized conditions (pH = 5, catalyst dosage = 3

Herein, we report the fabrication and characterization of phenyl hydrazine sensor based on ytterbium (Yb) doped ZnO flowers composed of nanorods prepared by simple hydrothermal process. The as-synthesized nanomaterial was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) attached with energy dispersive spectroscopy (EDS), Fourier transformation infrared (FTIR) and Raman-scattering spectroscopy which revealed the large-quantity synthesis, well-crystallinity and wurtzite hexagonal crystal structure of Yb-doped ZnO flowers. The fabricated phenyl hydrazine chemical sensor, by employing Yb-doped ZnO flowers as an electron mediator, exhibited sensitivity of ∼34.2 µA·mM-1 ·cm-2, detection limit of 24 mM and linear dynamic range of 0.25-4.0 mM. The presented work demonstrates that the Yb-doped ZnO nanomaterials are promising electron mediator which can be used for the fabrication of chemical sensors to detect various hazardous and toxic chemicals as phenyl hydrazine.

Herein, we report photocatalytic and fluorescence sensing applications of iron oxide (α-Fe₂O₃) nanoparticles synthesized by facile low-temperature simple solution process. The synthesized nanoparticles were characterized by several techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) attached with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), UV-visible spectroscopy and fluorescence spectroscopy. The detailed analysis revealed that the synthesized nanoparticles were well-crystalline, grown in very high density and possessing rhombohedral α-Fe₂O₃ crystal structure. The prepared nanoparticles were used as efficient scaffold for photocatalytic and sensing applications. The detailed photocatalysis results revealed that in presence of an appropriate amount of α-Fe₂O₃ nanoparticles as photocatalyst, a significant dye degradation of methyl orange (MO) was observed in 140 min. In addition, the fabricated florescence sensor based on α-Fe₂O₃ nanoparticles exhibited a low detection limit of ∼3.33 μM/L towards picric acid. The observed results clearly confirmed that the synthesized α-Fe₂O₃ nanoparticles are potential scaffold for photocatalysis and sensing applications.

Herein, the synthesis of mimosa pudica leaves shaped a-iron oxide (α-Fe2O3) nanostructures is reported through simple and facile hydrothermal process. The prepared α-Fe2O3 nanostructures were characterized in terms of their morphological, structural, compositional and optical properties through a variety of characterization techniques such as FESEM, EDS, XRD, FTIR and Raman spectroscopy. The detailed characterizations revealed the well-crystallinity and dense growth of mimosa pudica leaf shaped α-Fe2O3 nanostructures. Further, the prepared nanomaterials were used as efficient electron mediator to fabricate sensitive ethanol chemical sensor. The fabricated sensor exhibited a high sensitivity of -30.37 μAmM(-1) cm(-2) and low detection limit of -0.62 μM. The observed linear dynamic range (LDR) was in the range from 10 μM-0.625 μM.

This paper reports the facile synthesis and detailed characterization of mercaptoacetic acid capped cadmium sulphide (CdS) quantum dots using various cadmium precursors. The mercaptoacetic acid capped CdS quantum dots were prepared by facile and simple wet chemical method and characterized by several techniques such as energy dispersive spectroscopy (EDS), X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, UV-vis. spectroscopy, photoluminescence spectroscopy, high-resolution transmission microscopy (HRTEM) and thremogravimetric analysis. The EDS studies revealed that the prepared quantum dots possess higher atomic percentage of sulfur compared to cadmium due to the coordination of thiolate to the quantum dots surfaces. The X-ray and absorption analyses exhibited that the size of quantum dots prepared by cadmium acetate is larger than the quantum dots prepared by cadmium chloride and cadmium nitrate. The increase in size can be attributed to the low stability constant of cadmium acetate in comparison with cadmium chloride and cadmium nitrate. The FTIR and thermogravimetric analysis showed that the nature of capping molecule on the surface of quantum dots are different depending on the cadmium precursors which affect the emission from CdS quantum dots. Photoemission spectroscopy revealed that the emission of quantum dots prepared by cadmium acetate has high intensity band edge emission along with low intensity trapping state emission. However the CdS quantum dots prepared by cadmium chloride and cadmium nitrate produced only trapping state emissions.

Here we report a simple and effective method in tailoring the optoelectronic properties of semi-conducting metal oxide for suitable device application. Sol-gel synthesis was used to synthesize manganese doped TiO2 nanopowder and commercially available TiO2 nanopowder was used as reference material. Thick films of these powder were screen printed on FTO coated glass and annealed at 450 degrees C in ambient air. Separately, 60 μL of neodymium chloride prepared from neodymium oxide, 60 μL of ruthenium based commercial dye (N719) and 60 μL of extracts of calendula orange and dog flower were used as sensitizer to improve the photoconductance properties. Elemental analysis confirmed synthesis of composite material of Mn and TiO2. Morphological observation showed a uniform particles of 25 to 50 nm diameter. Optoelectronic properties were studied by using thick films of these powders as working electrode as a function of wavelength from 430 to 750 nm and the cyclic voltammogram were obtained by scanning potential from -1.5 V to +1.5 V at the illumination intensity of 1000 Wm(-2). Sensitization resulted in additional absorption and functional bands. Oxidation peak current was found decreasing with increasing wavelength. Sensitization with flower extract resulted in increased oxidation current at higher wavelength indicating the improved photoconduction in comparison with N719 and neodymium.

The biosynthesis of silver nanoparticles (AgNPs) was achieved for the first time using methanol leaf extract of C. didymobotyra and their in vitro antioxidant and antibacterial activities were also evaluated. Methanol leaf extracts of C. didymobotyra after mixing with AgNO3 solution showed the change in color from light brown to dark yellowish brown within 1 hour. UV-visible spectroscopy study showed the surface plasmon resonance at around 420 nm clearly indicating the biosynthesis of AgNPs. Transmission Electron Microscopy (TEM) analysis proved the presence of biosynthesized AgNPs in spherical shape with huge disparity in sizes. The average size of biosynthesized nanoparticle was about 18 nm. The occurrence of face centered cubic shapes of nanoparticles was established by X-ray diffraction (XRD) patterns. Further, Fourier transform infrared spectroscopy (FTIR) study showed the possible capping of AgNPs because of the active biomolecules present in the methanol leaf extract of C. didymobotyra. The antioxidant activities of biosynthesized AgNPs were evaluated by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging assay and found that AgNPs demonstrated a strong antioxidant properties compared to methanol leaf extract. Nevertheless, the biosynthesized AgNPs exhibited a strong antibacterial activity against all the tested human pathogenic bacterial strains compared to crude methanol leaf extract of C. didymobotyra. Thus, it is concluded that these biosynthesized AgNPs are cost effective, eco-friendly in nature and could be applied for developing new antibacterial drugs and other biomedical applications in near future.

B, N-codoped titania mesoporous crystals were prepared by the sol-gel method followed by a molten nitrate process to modify the sample morphology. The composition, morphology and microstructure of the obtained samples were characterized by X-ray diffraction (XRD), X-ray photoemission spectroscope (XPS), Brunauer Emmett Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). Fourier Transform Infrared spectroscopy (FTIR) revealed weak complex vibrations between the Ti-O oxide species and the unsaturated sites (Ti

Herein, the fabrication and characterization of highly sensitive and selective ethanol gas sensor based on CuO nanodisks is reported. The CuO nanodisks were synthesized by facile hydrothermal process and detailed characterization revealed the well-crystallinity, high-purity and high density growth of the prepared material. To fabricate the ethanol gas sensor, the prepared nanodisks were coated on alumina substrate. The fabricated sensor exhibited high-sensitivity and the recorded gas response (resistance-ratio), response time (τ res) and recovery time (τ recov) were 6.2, 119 and 35 s, respectively for 100 ppm of C₂H₅OH at 300 °C. Further, the fabricated sensor shows high selectivity towards ethanol gas compared to H₂ and CO gases.

Herein, we report the facile synthesis of high-aspect ratio perforated Co3O4 nanowires derived from cobalt-carbonate-hydroxide (Co(CO3)0.5(OH) 0.11H2O) nanowires. The Co(CO3)0.5(OH) 0.11H2O nanowires were synthesized by simple hydrothermal process at 120 °C while annealing of such nanowires at 400 °C leads the formation of perforated Co3O4 nanowires. The prepared nanowires were characterized by several techniques which confirmed the high aspect ratio and well-crystallinity for the synthesized nanowires. For application point of view, the prepared perforated Co3O4 nanowires were used as efficient electrode material to fabricate highly sensitive and selective hydrazine chemical sensor. The electrochemical impedance spectroscopy (EIS) technique was employed to confirm the successful modification of the electrode. The key parameters of chemical sensor, such as detection limit, sensitivity, and linear range, have been systematically explored. The fabricated hydrazine sensor displayed a rather low detection limit of 4.52 μM (S/N = 3), a good sensitivity of 25.70 μA · mM-1, and a wide linear range of 16.97-358.34 μM.

Herein, we report the synthesis, characterization and ethanol gas sensing application of Ag-doped ZnO nanoparticles. The nanoparticles were synthesized through a facile hydrothermal process and characterized through various characterization techniques. The detailed characterizations confirmed that the synthesized Ag-doped ZnO nanoparticles are grown in high density with an average diameter of ~20 ± 5 nm, possessing well-crystalline wurtzite hexagonal crystal structure and exhibiting good optical properties. The as-synthesized Ag-doped ZnO nanoparticles were further used as functional material to fabricate efficient ethanol gas sensor which exhibited excellent gas response. The detailed gas sensing experiments revealed that at an optimized temperature, i.e., 320 °C, the recorded gas response was 32.815 for 200 ppm concentration of ethanol gas. Finally, a plausible gas sensing mechanism was also presented in this paper.

In this study, Cu/Fe type mixed oxides catalysts with different ratios of metal irons are successfully synthesized via fixed hydrothermal treatment. The prepared samples were then characterized by a combination of several techniques, such as XRD, BET, SEM, H2-TPR and FT-IR. The catalytic activity enhanced with the increasing amount of Cu in the HT-precursors, but it decreases when the ratio of Cu/Fe is above 4. The influence of calcination temperature was also studied in the search of highly dispersed active catalysts. The catalytic test indicated that the Cu/Fe mixed oxides possessed outstanding highly activity towards toluene oxidation. The highest catalytic activity was exhibited by Cu4Fe-400 of which the T50 and T90 reaches at about 258 °C and 294 °C respectively.

Herein, flower-shaped ternary layered double hydroxides (LDHs) Mg3Al1-xFex-CO3 with tunable memory effect as promising adsorbents was developed for the removal of acid red 88 anionic dye. All the samples were prepared using a co-precipitation method and were thoroughly characterized using several analytical techniques. The influence of Fe/(Al + Fe) ratio on the memory effect and dye adsorption capacity of Mg3Al1-xFex-CO3 LDHs was evaluated. Among all samples, Mg3Fe0.1Al0.9CO3 LDH resulted in the best adsorption capacity of 2709 mg/g in the first cycle. Comparing to Mg3Al1-CO3 and Mg3Fe1-CO3 LDHs, it also showed much better cycling performance during 4 cycles at 30 °C and atmospheric pressure. The influence of regeneration temperature was also investigated and found that 400 °C exhibit best performance. The detailed studies demonstrated that the adsorption capacity of Mg3Al1-CO3 can be improved by partially replacing Al by Fe.

Nanobiotechnology has emerged as a promising technology to develop new therapeutically active nanomaterials. The present study was aimed to biosynthesize AgNPs extracellularly using Aspergillus niger JX556221 fungal extract and to evaluate their anticancer potential against colon cancer cell line, HT-29. UV-visible spectral characterization of the synthesized AgNPs showed higher absorption peak at 440 nm wavelength. Transmission Electron Microscopy (TEM) analysis revealed the monodispersed nature of synthesized AgNPs occurring in spherical shape with a size in the range of 20-25 nm. Further, characterization using Energy Dispersive Spectroscopy (EDX) confirmed the face-centred cubic crystalline structure of metallic AgNPs. FTIR data revealed the occurrence of various phytochemicals in the cell free fungal extract which substantiated the fungal extract mediated AgNPs synthesis. The cytotoxic effect of AgNPs was studied by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results evidenced the cytotoxic effect of AgNPs on HT-29 cell lines in a dose dependent manner. The highest activity was found at 100 μg/ml concentration after 24 h of incubation. Use of propidium iodide staining examination method confirmed the cytotoxic effect of AgNPs through inducing cell apoptosis. AgNPs cytotoxicity was found to be through elevating reactive oxygen species (ROS), and caspase-3 activation resulting in induced apoptosis. Therefore, this research finding provides an insight towards the development of novel anticancer agents using biological sources.

Well-crystalline multipod ZnO architectures made by accumulation of hexagonal nanorods were synthesized, characterized and used as efficient anode material for the fabrication of dye-sensitized solar cell (DSSC). The multipod ZnO architectures were synthesized by simple and facile hydrothermal process and characterized by several techniques to examine the structural, morphological, optical and photovoltaic properties. The morphological characterizations revealed that the synthesized multipod ZnO architectures were made of several hexagonal shaped ZnO nanorods which are originated from a single centre. The structural and compositional properties revealed that the nanorods are pure ZnO and possessing well crystallinity and wurtzite hexagonal phase. The assynthesized multipods ZnO architectures were utilized as potential anode materials for the fabrication of dye-sensitized solar cell (DSSC). The dye sensitized solar cells fabricated with multipods ZnO architectures photoanode attained a reasonable solar to electricity energy conversion efficiency of -1.9% with a photocurrent density i.e., short circuit current (J(sc)) of 4.59 mA/cm2.

This paper reports the temperature-dependant electrical characteristics of n-ZnO hexagonal nanorods/p-Si heterojunction diodes. The n-ZnO hexagonal nanorods were grown on p-Si substrate by a simple thermal evaporation process using metallic zinc powder in the presence of oxygen. The spectroscopic characterization revealed well-crystalline nanorods, quasi-aligned to the substrate and possessing hexagonal shape. The as-grown nanorods exhibited a strong near-band-edge emis- sion with very weak deep-level emission in the room-temperature photoluminescence spectrum, confirming good optical properties. Furthermore, the electrical properties of as-grown ZnO nanorods were examined by fabricating n-ZnO/p-Si heterojunction assembly and the I-V characteristics of the fabricated heterojunction assembly were investigated at different temperatures. The fabricated n-ZnO/p-Si heterojunction diodes exhibited a turn-on voltage of ~5 V at different temperatures with a mean built-in-potential barrier of 1.12 eV. Moreover, the high values of quality factor obtained from I-V analysis suggested a non-ideal behavior of Schottky junction.

α-Fe2O3 nanoparticles were synthesized by facile hydrothermal process at low-temperature and used as efficient anode material for the fabrication of lithium ion battery. The prepared nanoparticles were characterized in detail by various techniques such as X-ray diffraction pattern, field emission scanning electron microscopy (FESEM) combined with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) equipped with high-resolution TEM, Fourier transform infrared (FTIR) and Raman-scattering spectroscopy. The detailed characterizations revealed that the nanoparticles are synthesized in large quantity and possessing well-crystalline rhombohedral α-Fe2O3 structure. For application point of view, the synthesized nanoparticles were used as an anode material for fabrication of Li-ion battery. A coin cell of type-2032 was assembled using as-synthesized α-Fe2O3 nanoparticles and its charge-discharge profile was analyzed. Interestingly, it was observed that the cell delivered the first-charge capacity of 870 mAh g(-1) and the cell delivered a discharge capacity of 1500 mAh g(-1) during its first cycle.

This work reports a facile and large-scale synthesis of ZnO nanoparticles by simple self-propagating solution combustion method using dextrose as fuel and their effective use as a photocatalyst for photocatalytic degradation of Direct Red-23 (DR-23) dye in an immersion well type photo-reactor. The prepared ZnO nanoparticles were characterized by various analytical tools using field emission scanning electron microscopy (FESEM) attached with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) pattern, Fourier transform infrared (FTIR) spectroscopy and UV-Vis. spectroscopy measurements. The detailed characterizations confirmed that the prepared ZnO nanoparticles are pure, well-crystalline and possessing wurtzite hexagonal phase. Almost complete photo-degradation of the DR-23 was observed in 110 min. under UV irradiation in presence of ZnO nanoparticle photocatalyst. This study reveals that simply prepared ZnO nanomaterials are effective photocatalyst for the photocatalytic degradation of various toxic chemicals and pollutants.

Nanocrystalline Titanium Silicate-1 (TS-1) with attractive physical and chemical properties is being explored for the degradation of phenol. A fully dispersible nanocrystalline zeolite TS-1 was prepared. The catalyst was characterized by DLS, XRD, TEM and BET analyses. XRD analysis confirmed that the diffraction pattern of the NPs (CP-0) was very similar to that of amorphous silica and the aged concentrated precursor sample CP-48 showed peaks characteristic of MFI. TEM analysis confirmed that the size of the crystal is about 30 nm. The photocatalytic oxidation of phenol was studied over nanocrystalline Titanium silicate-1 thin film flow reactor. The experimental parameters such as aeration, flow rate, solution pH and phenol concentration were optimized. The degradation efficiency of choro-substituted phenols are compared at optimum conditions. In addition, photocatalytic degradation efficiency of simulated phenolic waste water was studied. The results are significant, as the method adopted here can be extended for the treatment and purification of waste water and air using nanocrystalline Titanium silicate-1 thin film flow reactor.

Carbon nanotubes (CNTs) are attracting increasing research interest as promising adsorbents for harmful cations, anions, and other organic and inorganic impurities present in natural sources of water. This study examined the feasibility of removing Rhodamine B dye from aqueous solutions using multi walled carbon nanotubes (MWCNTs) synthesized by chemical vapor deposition (CVD) method. The effects of dye concentration, pH and contact time on adsorption of direct dye by CNTs were also evaluated. The study used the Langmuir and Temkin isotherms to describe equilibrium adsorption. Additionally, pseudo second-order model was adopted to evaluate experimental data and thereby elucidate the kinetic adsorption process. The adsorption percentage of dye increased as contact time increased. Conversely, the adsorption percentage of dye decreased as dye concentration increased. The pseudo second-order model best represented adsorption kinetics. The capacity of CNTs to adsorb Rhodamine B was 65-90% at different pH values.

Aligned ZnO nanorods were grown on ZnO/Si substrate via simple aqueous solution process at low-temperature of - 65 degrees C by using zinc nitrate and hexamethylenetetramine (HMTA). The detailed morphological and structural properties measured by FESEM, XRD, EDS and TEM confirmed that the as-grown nanorods are vertically aligned, well-crystalline possessing wurtzite hexagonal phase and grown along the [0001] direction. The room-temperature photoluminescence spectrum of the grown nanorods exhibited a strong and broad green emission and small ultraviolet emission. The as-prepared ZnO nanorods were post-annealed in nitrogen (N2) and oxygen (O2) environments and further characterized in terms of their morphological, structural and optical properties. After annealing the nanorods exhibit well-crystallinity and wurtzite hexagonal phase. Moreover, by annealing the PL spectra show the enhancement in the UV emission and suppression in the green emission. The presented results demonstrate that simply by post-annealing process, the optical properties of ZnO nanostructures can be controlled.