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Herein, we report a successful synthesis of supramolecularly assembled polyaniline/silver oxide/graphene oxide composite (PANI/Ag2O/GO) for enhanced NO2 gas sensing application. The PANI/Ag2O/GO composite was synthesized by facile stirring followed by an ultrasonication process. The prepared material was characterized by different techniques such as x-ray diffraction, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and Raman-scattering spectroscopy. The detailed analysis revealed that the average crystallite sizes of PANI/Ag2O and PANI/Ag2O/GO composites were found to be 37.37 nm and 41.55 nm, respectively. FESEM and TEM analysis showed coral-like rough-surfaced and extensively agglomerated morphology for PANI and ultrathin flexible sheet-like morphology for GO. Ag2O nanoparticles with diameters 20–30 nm were well incorporated in the GO sheets and PANI matrix in the case of PANI/Ag2O/GO composites. The synthesized materials were used to make resistive sensor devices that had a high response to NO2 gas. The fabricated sensors were examined at various temperatures to obtain the optimal sensing temperature. The fabricated NO2 gas sensor device based on PANI/Ag2O/GO composite exhibited a highest sensitivity of 5.85 for 25 ppm at an optimized temperature (100 °C) as compared to the pure PANI (2.5) and PANI/Ag2O composite (3.25). Further, the fabricated sensor device based on PANI/Ag2O/GO composite was also examined at different NO2 gas concentrations.

In this study, the deposition parameters of the SU8 2000.5 negative photoresists have been investigated and optimized for the photolithographic technique. Then, applied the inductive coupled plasma reactive ion etching (ICP RIE) to produce V-shaped groove diffraction grating on a silicon substrate. Spin coater (speed: 1000 rpm) was used to coat the photoresist over the Si substrate. The observed photoresist film thickness was measured by ellipsometry and found to be 800 nm. Interestingly, the film exhibited some stability with increasing the spin speed. The thermogravimetric analysis was used to optimize the baking temperature which was found to be ~105 °C. Contrast curves were obtained experimentally and used to optimize the exposure energy along with the images obtained from the field emission scanning electron microscopy (FESEM). The optimized energy fluence was found to be 17 mJ/cm2. It was interesting to observe that the thickness of the photoresists film was increasing with the elevation of the exposure energy fluence. The FESEM images were used to optimize the ICP RIE etching process and the best etching conditions for the Si substrate were ICP power: 150 W, bias power: 100 W, and SF6 gas flow rate: 32 SCCM (standard cubic centimeters per minute), O2 gas flow: 8 SCCM, and Ar gas flow of 8 SCCM. It is worth to mention that well-defined V-shaped grooves were observed with a depth of 2 μm under the same experimental conditions.

ZnO–SnO2 nanocubes were used as promising material for efficient sensing of p-nitrophenol and faster photocatalytic degradations of dyes like methyl orange (MO), methylene Blue (MB) and acid orange 74 (AO74). ZnO–SnO2 nanocubes were prepared by the facile solution process at 50 °C using Zn(NO3)2·6H2O and SnCl2·2H2O as a precursor in the presence of ethylenediammine. The synthesized material was examined for its morphological, structural, crystalline, optical, vibrational, and compositional studies by using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy. FESEM studies revealed the formation of well-defined ZnO–SnO2 nanocubes where the structural examinations revealed the formation of a crystalline tetragonal rutile phase for SnO2 with some crystal sites doped with Zn. The as-synthesized nanocubes were explored for their photocatalytic activities towards three different dye viz. MO, MB, and AO74. Practically, complete degradation of AO74 was seen within 4 minutes of photo-irradiation in the presence of 0.05 g ZnO–SnO2 nanocubes. However, 97.17% and 41.63% degradations were observed for MB and MO within 15 and 60 minutes, respectively. All the dye degradation processes followed the pseudo-first-order kinetic model. Moreover, the as-synthesized nanocubes were utilized to fabricate highly sensitive and selective fluorescent chemical sensor for the detection of p-nitrophenol (PNP). ZnO–SnO2 nanocubes showed a very low detection limit of 4.09 μM for the detection of PNP as calculated according to the 3σ IUPAC criteria. Further, the as-synthesized ZnO–SnO2 nanotubes were found to be highly selective for p-nitrophenol as compared to the other two isomers.

Nanostructured ZnO doped with different Ce precursor concentrations (1, 5 and 10 mol%) has been prepared via co-precipitation method and tested for their photocatalytic and chemical sensing performances toward methyl orange (MO) and picric acid (PA) chemicals, respectively. After addition of Ce dopant, the spherical morphology of ZnO particles changed to a cone-like structure and exhibited the single-phase wurtzite structure, except for the 10 mol % dopant concentration. Blue-shift was detected in 5 mol% Ce doping, and this was found to be the optimum concentration for achieving the maximum dye degradation and sensing performances. The 5 mol% Ce doped ZnO expressed the complete MO degradation under UV light illumination, but the decrease in MO degradation with 10 mol% Ce doped ZnO was suggested to suppress the Ce3+ character in the sample. Facile redox couple Ce3+/Ce4+ appeared to improve the charge separation of Ce-doped ZnO upon UV illumination, forming the basis for release of O2, leading to increased catalytic and PA sensing performances.

In this paper, for the sorption of oil from oil polluted soil/water systems, nine new supramolecular organo-oil gelators were synthesized using three distinct diisocyanates and alcohols. The manufactured gelators were characterized using various techniques. The Fourier transform infrared (FTIR) and mass spectra confirmed the successful formation of the oil gelators. The synthesis of the proposed gelators was confirmed by the

The use of photocatalysts for acquiring direct photon energy from sunlight is a promising way to clean the environment, particularly the remediation of contaminants from water. In this work, firstly π-conjugated organic semiconductor configuring benzoselenadiazole, 4-(3,5-bis(trifluoromethyl) phenyl)-7-(5'-hexyl-[2,2'-bithiophen]-5-yl)-benzo [c] (Kümmerer, 2009; Chen et al., 2018; Randeep et al., 201) selenadiazole, abbreviated as (RTh-Se-F), was synthesized. The designed RTh-Se-F with an extended π-conjugation showed good optical properties in the visible region and estimated a low optical band gap of ∼2.02 eV . The molecular orbitals i.e. HOMO (-5.33 eV) and LUMO (-3.31 eV) for RTh-Se-F organic semiconductor were suitably aligned to energy levels of (Madhavan et al., 2010Madhavan et al., 2010)-Phenyl-C

Fungal abetted processes are among the finest approaches for the transformation or degradation and decolorization of dyes in effluents. In this piece of research; biodegradation and metabolic pathways of two toxic dyes Congo Red (CR) and Reactive black 5 (RB5) by two strains of Aspergillus sp. fungus in batch experiments has been investigated. Morphological characteristics of the isolates were observed with both light and electron microscopies. Based on molecular characterization the isolates were identified as Aspergillus flavus and Aspergillus niger. The degradation was also optimized via. operational parameters such as pH, temperature, incubation time, inoculums size, dye concentration, carbon sources and nitrogen sources. Degradation measurements revealed that the isolates effectively degraded 90% and 96% of CR and RB5 respectively. Metabolites were identified with Liquid chromatography-mass spectrometry (LCMS) and degradation pathways of the dyes were proposed. Toxicity assay Phaseolus mungo seeds showed that pure CR and RB5 dyes exhibits significant toxicity whereas fungal treated dye solution resulted in an abatement of the toxicity and cell viability was increased. The results stipulated in this article clearly showed the effectiveness of the isolates on detoxification of CR and RB5 dyes.

2D SnO2 disks with excellent purity and crystallinity were synthesized through a low cost, facile hydrothermal process and were characterized in terms of their morphological, structural, optical and electrochemical properties. The 2D disk-like morphology of synthesized SnO2 presented the average thickness of ∼1 μm and possessed the typical rutile tetragonal phase for the SnO2 with preferred growth along (100) plane. As-synthesized SnO2 disks were used for the fabrication of gas sensors for reducing gases like H2, CO, and C3H8. With the optimized temperature at 400 °C, the as-synthesized SnO2 electrode expressed the gas responses of 14.7, 9.3 and 8.1 for H2, CO, and C3H8, respectively. Contrary, the reasonable response times of 4 s, 3 s, and 8 s and the recovery times of 331 s, 201 s, and 252 s were recorded for H2, CO, and C3H8 gases, respectively. The DFT studies conducted herein suggest that the adsorbed oxygenated species act as a primary redox mediator for gas sensing reaction between reductive gases like H2, CO and C3H8, and SnO2 sensor. From DFT analysis, a very low heat of adsorption (≤0.2 eV) estimated which suggested the physisorption of the H2 molecules on the surface of the sensing material (i.e. SnO2). In contrast, the deposited oxygen atom forms strong chemical bonds with O2c and O3c sites. The oxygen atom bonded to O2c site control the conductivity of the sensor better than the O3c sites.

In this paper, Ag doped MnO2-CNT nanocomposite was fabricated by using simple co-precipitation route. The synthesized nanocomposite was employed as adsorbent for elimination of Acridine Orange dye. The structural analysis of as synthesized Ag doped MnO2-CNT nanocomposite confirms the presence of (111) plane of Ag, (104) of carbon and (110) plane of MnO2. Processing of operational variable parameters such as, pH, adsorbent dose, and initial dye concentration with respect to contact time on adsorption of Acridine Orange was optimized and evaluated using Response Surface Methodology. The fit of the predictive model for the removal of dye was in good agreement with the experimental value. Isotherm data was modelled by means of Langmuir, Freundlich, Temkin and Dubinin- Radushkevich isotherm. Langmuir isotherm offered the best fit to experimental data proposing homogeneous dispersion of adsorption sites. Furthermore, the suitability of the adsorbent was also investigated by fitting the adsorption data with pseudo-second-order kinetic model. The recuperation and reusability of the adsorbent and adsorbate has made this process inexpensive and appropriate for large scale applications.

Herein, we report the synthesis and analysis of fern shaped La2O3 nanostructures as potential scaffolds for efficient hydroquinone chemical sensing application. A facile, low-cost hydrothermal method was applied for the synthesis of 3D fern shaped La2O3 nanostructures. Several techniques were employed to characterize the synthesized La2O3 nanostructures. XRD analysis confirmed the hexagonal phase for the La2O3 nanostructures with an average crystallite size of 35.18 nm. FESEM and TEM analysis established the 3D fern shaped structures for La2O3 nanostructures with dendritic arms of different lengths alongside triangular-ovate outlines. Purity, composition and vibrational features were confirmed by EDS, FTIR and Raman spectroscopic studies. The fabricated 3D fern shaped La2O3 nanostructures modified glassy carbon electrode (GCE) showed remarkable electron mediating properties towards hydroquinone even at very low analyte concentrations. The linear dynamic range (LDR), experimental limit of detection (LOD) and sensitivity for 3D fern shaped La2O3 nanostructures modified GCE in phosphate buffer solution (PBS) were found to be 0.0781–0.625 mM, 0.0781 mM and 463.3 μA mM−1cm−2, respectively. Finally, a mechanism was also proposed for the electrochemical sensing of the hydroquinone. The presented work thus, confirms that the 3D fern shaped La2O3 nanostructures may be the future potential candidates for fabricating efficient and reproducible electrochemical sensors.

We demonstrate the preparation of nanostructures cobalt oxide/reduced graphene oxide (Co3O4/rGO) nanocomposites by a simple one-step cost-effective hydrothermal technique for possible electrode materials in supercapacitor application. The X-ray diffraction patterns were employed to confirm the nanocomposite crystal system of Co3O4/rGO by demonstrating the existence of normal cubic spinel structure of Co3O4 in the matrix of Co3O4/rGO nanocomposite. FTIR and FT-Raman studies manifested the structural behaviour and quality of prepared Co3O4/rGO nanocomposite. The optical properties of the nanocomposite Co3O4/rGO have been investigated by UV absorption spectra. The SEM/TEM images showed that the Co3O4 nanoparticles in the Co3O4/rGO nanocomposites were covered over the surface of the rGO sheets. The electrical properties were analyzed in terms of real and imaginary permittivity, dielectric loss and AC conductivity. The electrocatalytic activities of synthesized Co3O4/rGO nanocomposites were determined by cyclic voltammetry and charge-discharge cycle to evaluate the supercapacitive performance. The specific capacitance of 754 Fg-1 was recorded for Co3O4/rGO nanocomposite based electrode in three electrode cell system. The electrode material exhibited an acceptable capability and excellent long-term cyclic stability by maintaining 96% after 1000 continuous cycles. These results showed that the prepared sample could be an ideal candidate for high-energy application as electrode materials. The synthesized Co3O4/rGO nanocomposite is a versatile material and can be used in various application such as fuel cells, electrochemical sensors, gas sensors, solar cells, and photocatalysis.

Vanadium dioxide (VO2(M)) is a first order reversible thermochromic material which changes its phase at particular temperature and thus can be used as a thermochromic smart material for window coating. Similarly, the cerium dioxide (CeO2) is a well-known photo catalyst which can be applied on vanadium dioxide for self-cleaning. This paper reports a successful direct synthesis and detailed characterizations of core-shell VO2(M)@CeO2 spherical nanoparticles. In the core-shell nanoparticles, the vanadium dioxide core exhibits a solar light modulation property while cerium dioxide shell shows dye degradation through a facile photocatalytic process. Addition of ceria facilitates the VO2 (B) to VO2 (M) transformation and also improves its optical properties. With reduced transition temperature, the thermal stability was enhanced due to core –shell structure. To the extent of our knowledge, the synthesis of core-shell VO2@CeO2 nanoparticles is reported for the first time. The synthesized nanoparticles exhibited improved thermochromic and photocatalytic properties.

This review seeks to explore the literature pertaining to the applicability of nano-photocatalysts in fine chemical synthesis of organic compounds. The current methods of preparation of organic compounds in laboratories and industries are highly demanding on the non-renewable sources of energy. These conventional methods also generally require extreme conditions of temperature and pressure. Owing to deeper global awareness toward conservation of non-renewable sources of energy, there has been a shift of focus toward photocatalysis in the recent years. Photocatalysts are long known to catalyze various organic reactions such as oxidation, reduction, addition, cyclization and decomposition. The advent of nanotechnology made it possible to scale down these photocatalytic materials from bulk- to nano-scale and thereby further widen their scope and efficiency. Advances in material chemistry and nanotechnology have also made it possible to synthesize nanophotocatalysts of new genres, properties of which can be controlled and designed at molecular level. In this review, an attempt has been made to classify these diverse nanophotocatalysts into different groups, based on their composition and mechanism. Since the literature survey revealed that the chemoselectivity and efficiency of the nanophotocatalysts depend on their method of preparation, an overview of their common synthesis protocols is included. The review also highlights the various organic conversions for which these nanomaterials can be used under UV/visible irradiation. Nanophotocatalysts hold a great promise for environmentally-benign synthesis of highly useful organic compounds. We believe that this review can provide insights into research done in this field so far, which can pave way for further progress in this topic of far-fetched social significance. Keywords: Photocatalysis, Nano-photocatalysis, Organic synthesis, Green Chemistry, Photosensitization

Well crystalline Ag/CeO2 nano-structured material being utilized for its photocatalytic and antibacterial activities was synthesized via simple solution combustion synthesis (SCS) approach using tartaric acid as a fuel. Interconnection of Ag with CeO2 was investigated to determine its morphological, structural, crystalline, surface and optical properties using common characterization tools. The synthesized Ag–CeO2 materials are of high purity and well-crystalline, having a porous nature with an average pore size of ∼5–7 nm. As-synthesized Ag–CeO2 materials were utilized as photocatalyst for catalytic Rhodamine B (RhB) dye degradation under UV irradiation, showing the almost full degradation of RhB dye molecules in 150 min. As-synthesized Ag/CeO2 nanostructured materials were also investigated for their antibacterial activity toward gram positive (S. aureus) and gram negative (P. aeruginosa) strains of bacteria. The minimum inhibitory concentration for inhibiting the growth of S. aureus (gram positive) and P. Aureginosa (gram negative) were found to be 3.125 μg/ml and 6.25 μg/ml in the presence of Ag/CeO2 materials. The results obtained for Ag/CeO2 materials clearly displayed the significantly improved catalytic and antibacterial properties in comparison with pure CeO2.

Herein, we report the successful synthesis of different phases of VO2 nanomaterials via a facile hydrothermal method by simply varying the molar ratio of the reducing agent (citric acid monohydrate) to vanadium precursor (vanadium (V) oxide). Six samples were synthesized with corresponding variation in molar ratio of vanadium (V) oxide to citric acid monohydrate as 1:1, 1:1.5, 1:2, 1:3, 1:4 and 1:5, respectively. The synthesized nanomaterials were characterized by phase identification, morphologies, compositional, optical, thermal, and electrical properties. The detailed characterizations confirmed the formation of single phase VO2 (B), VO2 (M) and amorphous VO2 by the mere variation of relative concentrations of reducing agent. Even though the synthesis of single phase VO2 is challenging and interestingly, a simple, one-step hydrothermal process procedure was used to produce pure phaseVO2 without the use of inert environment or post-synthesis heat treatments.

Herein, we report a simple, low-temperature, ecofriendly synthesis of graphene oxide nanosheets (GONs). Graphite powder was treated with KMnO

Herein, we report, for the first time, the synthesis, characterization, and the photocatalytic methyl blue dye degradation performance of magnesium oxide (MgO) nanoparticles (NPs) synthesized by a facile green approach using Camellia sinensis (tea leaves) extract as a reducing agent. The as-prepared materials were characterized by x-ray diffraction (XRD), which confirmed the large-scale synthesis of well crystalline cubic crystalline phase MgO NPs. Rietveld refinement analysis of the XRD pattern was done to determine the crystallographic parameters of the MgO NPs and to investigate lattice defects. Microstrain, lattice stress and energy density were calculated using Williamson-Hall analysis The synthesized nanoparticles exhibited over 97% photocatalytic degradation efficiency of methylene blue (MB) dye. Complementary density functional theory (DFT) calculations revealed the favorable formation of O\ud \ud \ud \ud 2\ud \ud \ud −\ud \ud \ud radicals on the MgO (001) surface as the drivers of the MB dye degradation.

Herein, we report a bacteria-based strategy as an efficient, reasonable, benign, and promising methodology for remediating heavy metals fed waterbodies. The contemporary study deals with isolating, screening, and characterizing heavy metal resistive bacteria from metal-rich sites. The transcriptome analysis reveals the identity of the isolated species as Bacillus pumilus and Bacillus cereus. Batch studies put forth the bioremoval results in designed conditions of different pH, concentration, dose, and time. The mechanistic actions are drawn using complementary techniques such as Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The theory of surface adsorption of lead (Pb(II)) and nickel (Ni(II)) is further fostered by the application of adsorption isotherms. The conducted studies establish the bacterial morphological stratagems and multifarious biochemical approaches for countering metallic ions of Pb(II) and Ni(II). The exhibition of significant removal results by the isolated bacterial strains in simulated water samples with remarkable proliferation rates has opened up its favorability for industrial platforms.

Here, we report the biogenic preparation of luminescent copper oxide (CuO) nanoparticles via peel extracts of Musa acuminate. The current methodology provides the sustainable alternative of using agricultural fritter as effective stabilizing and reducing agent during the synthesis of CuO particles. The parameters governing the optimization of CuO nanoparticles were scrutinized by varying the concentrations of copper salt, stirring rate and pH of the reaction media. The toxicity profiling of CuO nanoparticles over the germination of Vigna radiate. Allium cepa genotoxicity and antibacterial assay were also examined to verify the biocompatibility of prepared CuO particles. The in-vitro biocompatibility of the developed nanoparticles was tested against mouse L929 fibroblastic cell lines by using MTT assay in range of 1–80 μg/mL. The distinctive optical and luminescence properties have been employed for sensing application for heavy metal ions using UV–vis. and fluorescence spectrophotometric analysis. The value of detection of limit for the developed sensor was found to be 2 μg/L. The low values of detection limits facilitate the practical utilization of CuO nanoparticles for sensing applications. As prepared CuO nanoparticles can act as a biocompatible fluorophore nominee to substitute existing dyes. The current study provides the additional advancement towards the sensing of toxic metal using green and safe CuO nanoparticles.

Bitter gourd shaped ytterbium oxide (Yb2O3) doped ZnO nanostructures were synthesized through hydrothermal method and analyzed using various techniques including field energy emission scanning electron microscopy (FESEM) accompanied with energy dispersive spectroscopy (EDS), X-ray diffractometry (XRD), UV-visible spectroscopy and Raman spectroscopy. Yb2O3 doped ZnO product showed long oblong shaped structures with distinct crunchy and warty exterior texture similar to the bitter gourd fruit. The average length of the bitter-gourd fruit shaped structures was ∼3.5 μm. The calculated average crystallite size and band gap energy of Yb2O3 doped ZnO nanostructures were 18.75 nm and 3.34 eV, respectively. The silver electrode (AgE) modified electrochemical sensor fabricated using bitter gourd shaped Yb2O3 doped ZnO nanostructures exhibited excellent sensitivity of 117.6 μA.mM−1cm−2, measured LOD of 0.39 mM, linear dynamic range (LDR) of 0.39 mM–6.25 mM and regression correlation coefficient (R2) = 0.94892.

Silver embedded banana peel biochar (Ag-BBc) composite was tailored effectively by green synthetic route. Azadirachta indica leaf extract was employed for preparation of Ag nanoparticles as reducing agent and biochar was derived from the of banana peel via pyrolysis. The multi-functionality of the fabricated nanocomposite was investigated through its application towards energy storage and environmental remediation. The prepared composite was characterized in detail by various analytical techniques and the electro-chemical aspects were examined by cyclic-voltammetry and galvanostatic charge-discharge methods. The improved specific capacitance of Ag-BBc composite was measured as 655 Fg-1 in 1 M Na2SO4 at a current density of 0.35 Ag-1. The Ag-BBc modified electrode exhibited an excellent cyclic stability of 79.3% after 5000 charge/discharge cycles and displayed high energy and power density of 40 Wh/kg and 490 Wkg−1 respectively, at 1 Ag-1. Furthermore, Ag-BBc composite was used for the ultrasonic assisted adsorption of Congo Red dye with appreciable adsorption efficacy of ∼98% within 5 min of contact time. Langmuir and Freundlich isotherms were considered to describe the equilibrium of dye using ultrasonic assisted adsorption process.

Recently, because of excellent electrical conductivities and many active sites, transition metal sulfides have been utilized as efficient electrodes for supercapacitors. Herein, we synthesize hierarchical MoS2/Ni3S2 structures grown on nickel foam by a facile one-pot hydrothermal process. The as-fabricated asymmetric hybrid capacitor based on hierarchical MoS2/Ni3S2 electrode exhibit a specific capacitance of ∼1.033 C/cm2 at 1 mA/cm2. Furthermore, the hybrid capacitor unveils an energy density of 35.93 mWh/cm3 at a power density of 1064.76 mW/cm3. The observed results clearly revealed that the synthesized MoS2/Ni3S2 structure might be used as potential electrode material for future energy storage devices.

Herein, we report the synthesis and characterization of rGO-CdS heterostructure and their utilization as an efficient material for sensing and visible-light driven photocatalytic degradation applications. The heterostructure was synthesized by facile hydrothermal process and characterized by several techniques which exhibited intriguing compositional, morphological, structural, thermal, textural and photo-physical properties. The high resolution transmission electron microscopy (HRTEM) images of the prepared rGO-CdS heterostructure showed the successful deposition of CdS nanoparticles (CdS NPs) on the surface of reduced graphene oxide (rGO) sheets. The synthesized rGO-CdS heterostructure was employed as an outstanding fluorescent sensor for the selective and sensitive detection of heavy transition metal ion; Ag(I) and a synthetic food colorant; sunset yellow (SY). The detection limit of 12.35 μM and 7.89 μM was found to be for Ag(I) and SY, respectively. The prepared rGO/CdS heterostructure was also successfully applied for the photocatalytic degradation of fluoroquinoline antibiotic, levofloxacin (LVX), and food colorant SY under visible-light irradiation. The removal efficiency of 82.7% was obtained for LVX (10 mg/L) using rGO-CdS heterostructure in 60 min under visible-light irradiation. The synthesized heterostructure displayed enhanced photocatalytic decomposition (82.7%) than pure CdS NPs (67.5%) under optimized reaction conditions (0.50 g/L photocatalyst amount, 10 mg/L LVX initial concentration and pH 9.0). Approximate 66% of SY was degraded in 270 min under visible-light using the prepared heterostructure. The scavenger study confirmed the pivotal role of e, O2 , OHs and OH in the photocatalytic decomposition process. The amended photocatalytic behaviour of the rGO-CdS heterostructure could be accredited to the enhanced visible light harvesting capability, effective charge separation and transportation of photogenerated charge carriers across the heterojunctional interface. To the best of our knowledge, this is the first report till date on the utilization of rGO-CdS heterostructure for the fluorescence sensing of Ag(I) and SY as well as photocatalytic degradation of LVX and SY.

Developing biomaterials based on the natural biomacromolecule silk sericin from Bombyx mori cocoon is of great interest for biomedical application. Dialdehyde carboxymethyl cellulose (DCMC) is derived from periodate oxidation of carboxy- methyl cellulose. Here, we developed a novel strategy of cross-linking of sericin with DCMC via the Schiff's base reaction. Fourier transform infrared spectroscopy and scanning electron microscopy indicated the formation of Schiff's base via the blending of sericin and DCMC. The mechanical properties tests suggested the covalent cross-linking effectively enhanced the tensile strength of sericin. The swelling test and water contact angle indicated the DCMC/SS film had excellent hydrophilicity, swellability. Additionally, we demonstrated the DCMC/SS film had excellent blood compatibility, cytocompatibility and promoting cell proliferation activity by the hemolysis ratio analysis, cell adhesion, cells viability and proliferation assays. The prepared DCMC/SS film has shown great promise in biomedical applications such as wound dressing, artificial skin and tissue engineering.

Herein, we report the successful synthesis of BiF3 octahedrons via facile hydrothermal process as potential solar light active catalyst for the photocatalytic degradation of Rhodamine B (RhB) dye in aqueous phase. The synthesized BiF3 octahedrons were characterized by several techniques such as X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), Fourier transform infrared (FT-IR) spectroscopy, UV-diffuse reflectance spectroscopy (UV-DRS), photoluminescence (PL) spectroscopy, thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET) techniques in order to observe the structural, morphological, optical and luminescence properties. The synthesized octahedrons possess the high density growth, pure and well-crystalline with cubic phase structure and band gap of 3.98 eV. As a potential solar light active photocatalyst , the synthesized BiF 3octahedrons exhibited ˜95.7% degradation of RhB in 50 min. The effect of different process parameters such as pH and catalyst dose on the degradation of RhB was also explored. Interestingly, the synthesized BiF3 octahedrons demonstrated better photocatalytic performance compared to several commercially available photocatalysts such as TiO2 (PC-500), SnO2 and ZnS. Further, it was observed that the degradation of RhB over the prepared BiF3 octahedrons obeyed the pseudo first-order reaction kinetics with rate constant of 0.06393 min−1. The scavenger experiments verified the role of h+, e, O2 , OH and OHs in the photocatalytic degradation process and a plausible photocatalytic mechanism has also been proposed.

Reduced graphene oxide modified by hyperbranched polyamine-ester (RGO-HBPE) liquids was successfully fabricated through the surface chemical engineering and tested for serving as a solvent-free novel lubricant. Structural characterization, dispersibility and rheology behavior of the lubricant and the related frication performance on steel plate were investigated thoroughly. The results manifest that the RGO-HBPE exhibited good dispersity in distilled water and liquid behavior without any solvent at ambient temperature. And this RGO-HBPE liquids could be directly introduced onto the surface of steel plate as lubricants without any additional base oil. Tribological results and the proposed lubricating mechanism of RGO-HBPE imply that the fluidity of RGO-HBPE is favorable for lubrication and is crucial to reduce the friction coefficient. The spontaneous flow of RGO-HBPE provide a spreading effect to form the lubricating film. The specific spreading effect of RGO-HBPE and the synergistic lubricating effect between HBPE and graphene demonstrate that RGO-HBPE could be directly used as promising candidates for lubricants in nowadays moving machines.

Nitrogen-doped carbon quantum dots (N-CQDs) were successfully synthesized using rice residue and glycine as carbon and nitrogen sources by one-step hydrothermal method. High quantum yield (23.48%) originated from the effective combination of nitrogen with various functional groups (C O, N H, C N, COOH and C O C). The N-CQDs showed a fluorescence with the wavelength varied from 420 to 500 nm and the maximum emission wavelength being at 440 nm. N-CQDs have been importantly applied as probe to detect Fe3+ and tetracycline (TCs) antibiotics with remarkable performance. Using the linear relationship between fluorescence intensity and Fe3+ concentration, the N-CQDs could be employed as a simple, efficient sensor for ultrasensitive Fe3+ detection ranging from 3.32 to 32.26 µM, with a limit of detection (LOD) of 0.7462 µM. The N-CQDs showed the applicability to detect TCs. The detection limits of tetracycline, terramycin and chlortetracycline were 0.2367, 0.3739 and 0.2791 µM, respectively. The results of TC by fluorescence method in real water samples were in good agreement with standard Ultraviolet–visible (UV–vis) method. The N-CQDs have various potential applications including sensitive and selective detection of Fe3+ and TCs, and cellular imaging with low cytotoxicity, good biocompatibility and high permeability.

Herein, we report the synthesis, characterization and enhanced adsorption studies of porous octahedral shaped Cu-BTC (copper benzene-1,3,5-tricarboxylate) metal organic frameworks (MOFs). The Cu-BTC MOFs were synthesized by facile hydrothermal process and characterized by various techniques in order to examine the structural, morphological, thermal and adsorption-desorption properties. The synthesized Cu-BTC MOFs were used as potential scaffold for the adsorption of highly toxic azo dye, i.e. methylene blue (MB). Detailed adsorption studies on the effect of initial pH, concentration, reaction time and temperature on adsorption of MB were analysed and it was observed that the removal of MB followed pseudo-2nd order kinetic model. Freundlich model fitted well as compared to Langmuir model with R2 of 0.975 and thereby signifying a multilayer adsorption of MB on the surface of Cu-BTC MOFs. The observed maximal adsorption capacity for MB removal (200 mg/L) was ∼101.21 mg/g using Langmuir isotherm. The Cu-BTC MOFs exhibited 42.3 mg/g adsorption capacity after fourth cycle of MB dye adsorption. These features exhibited that Cu-BTC MOF have potential for the adsorption of MB and can efficiently be used to treat wastewater.