Search

The design and engineering of plasmonic metal nanocomposite photocatalysts offer an operative approach for highly efficient CO2 photoreduction. Herein, the authors report a plasmonic 3D flower-like...

Cu serves as a co-catalyst, an electron mediator, and a dopant leading to a high enhancement in the photocatalytic activity of Cu-ZnO/Cu/g-C3N4 Z-scheme photocatalyst.

Polianthes tuberosa (Linn.) is traditionally considered an ornamental and medicinal plant worldwide. However, extensive studies on its phytochemical composition are very limited. Hence the present work aims to identify the total phytochemical ingredients present in different crude extracts of tuberosa. Phytochemical analysis has been carried out for differential cold solvent extracts of various parts of tuberosa such as petals, stamens, and ovary by gas chromatography coupled with mass spectrometry, ultra-performance liquid chromatography to quadrupole time-of-flight mass spectrometry, and evaporative light scattering detector analyzers for the identification of bioactive components. Among the various solvents used for the extraction, diethyl ether is found to be the most suitable and efficient solvent, as its total differential recovery from the crude extract is about 0.24% as compared to 0.04% obtained by using n-hexane or petroleum ether. Numerous phytochemicals have been identified by the chromatography and MS techniques, which demonstrate the presence of essential fatty acids along with other pharmacological importance phytoconstituents. Identification of additional phytochemicals present in the crude extract of tuberosa flower further enhances its biological and pharmacological significance. The present work lays a foundation for further research and development of phytoconstituents of the tuberosa flower.

Synthesizing nanomaterials at the expense of solar energy and the associated energy generation have utmost significance as far as environmental sustainability is concerned. Here, sunlight-assisted ...

Efficient production of hydrogen through photocatalytic water splitting requires innovative catalyst design. One of the potential ways to enhance the photocatalyst's efficiency is to prepare metal oxide heterostructures. Herein, we report fabrication of a novel heterostructure consisting of oxides of cesium, bismuth, titanium and zinc (Cs2O–Bi2O3–TiO2–ZnO) by a simple solution combustion method. Diffusion pathway of charge carriers in the as-synthesized Cs2O–Bi2O3–TiO2–ZnO is investigated by high resolution Valence Band X-Ray Photoelectron Spectroscopy (VB-XPS) and electron spin resonance studies. On the basis of analytical findings and redox potential values of each photocatalytic component, a plausible mechanism is proposed showing the formation and diffusion of charge carrier. The results suggest that the charge carrier migration follows the heterojunction approach among TiO2, Bi2O3, and ZnO and the Z-scheme approach between each of them and Cs2O. The performance of the as-obtained catalytic system is investigated by quantifying the photocatalytic formation of oxygen and hydrogen gases, as well as photoelectrochemical water oxidation under simulated sunlight irradiation. In addition, the apparent quantum efficiency is estimated as high as 1.56% at 420 nm. The high apparent quantum efficiency is primarily ascribed to the synergetic effect between Z-scheme and heterojunction operative in the as-prepared heterostructure.

Synthesis of metal oxide nanostructures through combustion routes is a promising technique owing to its simplicity, rapidity, scalability, and cost-effectiveness. Herein, a sunlight-driven combustion approach is developed to synthesize pristine metal oxides and their heterostructures. Sunlight, a sustainable energy source, is used not only to initiate the combustion reaction but also to create oxygen vacancies on the metal oxide surface. ZnO nanostructures are successfully synthesized using this novel approach, and the products exhibit higher photocatalytic activity in the decomposition of methyl orange (MO) than ZnO nanostructures synthesized by the conventional methods. The higher photocatalytic activity is due to the narrower band gap, higher porosity, smaller and more uniform particle size, surface oxygen vacancies, as well as the enhanced exciton dissociation efficiency induced by the sunlight. Porous Fe3O4 nanostructures are also prepared using this environmentally benign method. Surprisingly, few-layer Bi2O3 nanosheets are successfully obtained using the sunlight-driven combustion approach. Moreover, the approach developed here is used to synthesize Bi2O3/ZnO heterostructure exhibiting a structure of few-layer Bi2O3 nanosheets decorated with ZnO nanoparticles. Bi2O3 nanosheets and Bi2O3/ZnO heterostructures synthesized by sunlight-driven combustion route exhibit higher photocatalytic activity than their counterparts synthesized by the conventional solution combustion method. This work illuminates a potential cost-effective method to synthesize defective metal oxide nanostructures at scale. Copyright - 2019 American Chemical Society. This study was supported by University Grants Commission, India, under University with Potential for Excellence (UPE) program at University of Mysore, UGC JRF (Award No. F.19-1/2013(SA-I)), and Deanship of Scientific Research (DSR) at King Fahd University of Petroleum & Minerals (KFUPM) through project no. DF181021. Scopus

A novel NLO compound (E)-1-(5-chlorothiophene-2-yl)-3-(4-dimethylamino) phenyl) prop-2-en-1-one has been synthesized by adopting claisen schmidt condensation reaction method and the single crystals are grown using slow solvent evaporation technique. The FT-IR spectrum confirms the various functional groups present in the compound. The crystal structure was studied by XRD method, which reveals that the compound crystallizes in Monoclinic crystal system with a space group P21/n and the corresponding lattice parameters are a = 7.595 (2) Å, b = 17.441 (4) Å, c = 10.917 (3) Å, α = 90o, β = 102.500 (12)o, γ = 90o. UV-Visible spectrum shows that the crystal is transparent in the entire visible region. Refractive index of the crystal was determined using Brewster’s angle method. Thermal stability of the material was determined from TG/DTA test. The Second harmonic generation efficiency of the crystal was estimated using NLO test and the efficiency was found to be 0.84 times that of UREA.

A novel heterocyclic compound, 1-(4-methoxy phenyl)-2-((5-(1-(naphthalen-1-yloxy) ethyl) -[1,3,4]-oxadiazol-2-yl) sulfanyl) ethanone was synthesized using standard method and chemical structure of the synthesized compound was identified using FTIR spectrum. Needle shaped single crystals have been grown using solution growth technique. The grown crystals were characterized using single crystal XRD, UV-visible and Thermal analysis. The crystal structure study shows that the compound crystallizes in Monoclinic crystal system with a space group of P21/a and cell parameters are determined. UV-Visible study shows that the crystal is transparent in the entire visible region. The thermal stability of the material was determined by TG and DTA analysis.

Bio-hydrothermally synthesized ZnO nanoparticles (NPs) were coated ex situ on degummed silk fibers and subjected for X-ray diffraction, Scanning Electron Microscopy, and Energy dispersive spectroscopic characterization. Both coated and/uncoated fibers were sterilized by autoclave and ethylene oxide. Effect of coating and sterilization on mechanical properties of fibers was evaluated measuring its tensile strength. Antibacterial efficacy of coated fibers was assayed against Staphylococcus aureus. PXRD of uncoated and ZnO NPs coated fibers fairly differ, with former exhibiting highly amorphous nature and latter showing additional ZnO peaks at 34.42° and 36.41° corresponding to (002) and (101) planes with decreased amorphousness. SEM demonstrated spherical and agglomerated NPs on entire fiber surface and EDS confirmed presence of Zn. Coated fibers had significant improvement in tensile strength, measuring 2.2 N/m2 against 0.82 N/m2 of uncoated silk fibers. Autoclaving affected tensile strength of both coated and uncoated fibers detrimentally though coated fibers showed better resistance. Antibacterial activity of coated fibers was excellent on day 2 (1.9 cm zone of inhibition), which gradually declined by 6th day showing that coated fibers have consistent antibacterial activity against S. aureus. Hence, coating with ZnO NPs caused improvement in mechanical properties and antibacterial properties of degummed silk fibers, which could be a potent biomaterial for biomedical applications.

A facile fabrication and processing of cerium oxide-graphene oxide (CeO2-GO) hybrid nanocomposites without the use of any surfactant or any organic solvents using chemical method and treatment with microwave irradiation technique are reported. In-situ hexagonal nano cerium oxide particles embedded on the layered surface of GO sheets were investigated for the photodegradation of dyes, removal of chromium Cr(VI) ions and against antibacterial studies. The results imply that hybrid nanocomposites shows enhanced 5-folds of photocatalytic activities in UV (ultraviolet) light irradiation and exhibited rapid efficiency in the elimination of chromium ion better than the pure GO and CeO2, which are inhibited by competent photosensitive electron inoculation and controlling the electron-hole recombination. The synergetic effect of CeO2-GO composites played a vital role in showing better results against model bacterium than GO and CeO2 are due to higher physical interaction endorsed to the stress of membranes acute by piercing edges, large surface area, and higher adsorptive conditions of graphene oxide sheets tailored with ceria particles. The amount of charge transferred at the interface increases with the concentration of O atoms, demonstrating the interaction between CeO2 and GO is much stronger than CeO2 and GO are due to the decrease of the average equilibrium distance between the interfaces. The CeO2-GO interface staggered band alignments existing between the CeO2 surfaces and GO which shows an excellent synergism. The structure and morphology of composites were tested by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman, X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscope (HR-TEM).

ZnO nanoparticles synthesized using Gallic acid isolated from Phyllanthus emblica aqueous extract that designated as Pe ZnO, was subjected for structural and morphological characterization. For in vitro cyto-toxicity assessment of Pe ZnO, Hemolytic assay and Cell Counting Kit assay (CCK 8) on balb 3T3 fibroblasts were conducted while silkworm Bombyx mori larvae were used for in vivo bio-toxicity assay. In dentistry, clinically advocated ZnO (presented as D ZnO) of ∼2 μm size was used as control. Characterization results revealed that Pe ZnO is highly crystalline with hexagonal wurtzite structure and morphologically spherical with an average size of 38 nm as confirmed by X-ray diffraction, electron microscopy and dynamic light scattering techniques. Haemolysis assay at all the tested concentrations exhibit that, lysis of Red Blood Cells by Pe ZnO remained well within toxicity limit of 3% whereas D ZnO showed ∼5.2% hemolysis. Interestingly, Pe ZnO nanoparticles caused less than 36% growth inhibition of 3T3 cells at the highest concentration (2 μl) against 44% by D ZnO. Notably, in vivo study showed 26.67 and 96.67% death of the larvae at highest concentration 0.032 mg/mL of Pe ZnO and D ZnO respectively indicating Pe ZnO is less toxic than commercially available ZnO. Thus, we proved that green hydrothermally synthesized ZnO (PeZnO) is highly biocompatible and therefore propose to consider as potent compound for further evaluation using mammalian models followed by clinical trials.

A facile synthetic route and growth mechanism of phytochemicals stabilized zinc oxide (ZnO) nanoparticles have been developed using Thymus vulgaris (Thyme) leaf extract via hydrothermal method. Using thyme leaf extract as a size reducing agent with zinc nitrate as precursor via hydrothermal method is the novelty of this work. Presence of flavonoids, phenols and saponins in Thyme leaf extract has served as both reducing and stabilizing agents that play a critical role in the production of ZnO nanoparticles. The obtained ZnO nanoparticles having 50−60 nm size with an irregular shape. The in-vitro antioxidant activity by DPPH assay showed prominent activity (

Scheelite monoclinic bismuth vanadate nano-articulate crystals have been synthesized by using 1% sodium dodecyl sulphate as surfactant and ammonia as pH controlling agent at 180⁰C for 4 hr (at pH = 0, 1, 3, 6 and 8) under facile hydrothermal conditions. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). XRD and FE-SEM confirm the formation of monoclinic structures at all pH ranges and a preferential crystal growth (crystallite size 20-30 nm) has been observed along {040} facet with increase in NH4OH concentration. This selective growth resulted in structure enhanced performance of photocatalytic degradation of organic dyes and bacterial inactivation. Photocatalytic inactivation of methicillin resistant Staphylococcus aureus (MRSA) and comparison of the results to the oxidation of Procion Red MX-5B, Alizarin Red S and Cibacron Brilliant Yellow 3G-P dyes using bismuth vanadates has been reported originally in this paper.

Many reports describe the influence of additives or impurities on the physicochemical properties of crystals. On having obtained trans-[RuCl2(C5H5N)4] as brown, needle-shaped crystals contrary to red or orange-red blocks reported previously, we herein revisit its study. This complex was obtained from the filtrate of an ensuing reaction mixture of RuCl3·3H2O, bis(2-hydroxy-l-naphthaldehyde)adipoyldihydrazone (npahH4) and pyridine in methanol. Findings from X-ray crystallographic data and spectra of IR, UV-Visible, 1H and 13C NMR along with other analytical studies of the complex are presented here. A comparative study with previously reported crystal forms was performed to understand the accompanying molecular structural differences in the physical (shape, size and color) morphological alteration. Further probing into molecular dynamics, the molecular interactions were analyzed and quantified using computational methods. The symmetry of intermolecular interaction in C—H⋯Cl is different from earlier reported crystal forms. The intercontact H⋯H showed a major contribution (62.9%) for Hirshfeld surfaces. Also, we report antibacterial activity of the complex against methicillin-resistant Staphylococcus aureus followed by the in silico docking study that revealed its interaction with the residue Glu58 of ATPase subunit of S. aureus GyrB. Additional studies on its toxicity using rat models revealed this complex as non-toxic to animals. Synopsis: The crystal and colour morphology of a polymorph of trans-[RuCl2(py)4] have been studied by different investigations. The intercontacts have been discussed. The significant influence of a dihydrazone in morphological changes is revealed. The biological aspects have been further investigated through non-toxicity, antimicrobial screening and molecular docking studies against pathogen S. aureus.

BACKGROUND Facile, environmental friendly synthesis of metal oxide nanoparticles is of paramount importance when its biological applications are considered. OBJECTIVE Current study reports phyto-fabrication of Zinc oxide nanoparticles using aqueous extract of Piper betel leaves as stabilizing and capping agent using co-precipitation method. RESULTS P betel synthesized ZnO nanoparticles (PZnO) was characterized using Powder X-ray diffraction, UV-Visible spectroscopy, scanning electron microscopy and dynamic light scattering. PXRD pattern demonstrated hexagonal wurtzite structure with preferred orientation (100) plane confirmed by JCPDS file 36-1451. UV- Vis spectroscopy showed peak at 370 nm due to band edge of semiconductor, the PZnO. The average particle size determined by DLS measurement was 69 nm and morphologically the particles were short rod shaped and agglomerated as demonstrated by SEM images. Antibacterial activity of PZnO against dental pathogens namely Streptococcus mutans and Lactobacillus acidphillus was performed using well-diffusion method and antioxidant activity against 2, 2 diphenyl 1 picrylhydrazyl (DPPH) free radicals and were compared with ZnO used in clinical dentistry (DZnO). PZnO showed higher antioxidant activity of ~70% at 200 µg/mL with consistent activity at lower aliquots. PZnO showed higher antimicrobial activity than DZnO against both tested microbes and also exhibited inhibitory effects in concentration as low as 3.25 µg/mL. Cytotoxicity study using Balb 3T3 mouse fibroblast cell lines showed

The single crystal X-ray of three chalcone derivatives, (2E)-3-(2-chlorophenyl) -1-(4-ethoxyphenyl) prop-2-en-1-one (I), (2E)-3-(3-chlorophenyl)-1-(4-ethoxyphenyl)prop-2-en-1-one (II) and (2E)-1-(4-ethoxyphenyl)-3-(4-methoxyphenyl)prop-2-en-1-one (III) was determined. The compound (I) crystallized in triclinic P−1 crystal system and in the asymmetric unit of the compound (I), two molecules were present. The conformational differences between molecule A and B indicated with the dihedral angles of 3.47 (2)° (A) and 8.12 (16)° (B), measured between chlorophenyl ring (C1A/B-C6A/B) and methoxy phenyl (C10A/B–C16A/B). Similarly the compound (II) crystallized in monoclinic P−1 crystal system and in the asymmetric unit of the compound (II), two molecules were present. The conformational differences between molecule A and B with the dihedral angles of 4.50 (11)° (A) and 3.94 (11)° (B) was measured between terminal phenyl rings. The compound (III) crystallized in monoclinic, P21/n, with a dihedral angle between two terminal phenyl rings is 13.18 (7)°, indicating the near planarity of the compound. The intramolecular hydrogen bond of the types C—H…O is observed in all compounds (I), (II) and (III). In the crystal structures (I), (II) and (III), C—H…π intermolecular interaction was found in all compounds. The intermolecular hydrogen bond of the type C—H…O was present in compounds (I) and (II). The Hirshfeld surface analysis was carried for compounds (I), (II) and (III). Intercontacts C C, C H, C O, H H and O H were common in all compounds which contributed more to the Hirshfeld surfaces. The electrostatic potential surfaces were drawn to understand electrophilic and nucleophilic regions on the molecule.

Limited light absorption, inefficient electron-hole separation, and unsuitable positions of conduction band bottom and/or valence band top are three major critical issues associated with high-efficiency photocatalytic water treatment. An attempt has been carried out here to address these issues through the synthesis of direct Z-scheme Cs2O-Bi2O3-ZnO heterostructures via a facile, fast, and economic method: solution combustions synthesis. The photocatalytic performances are examined by the 4-chlorophenol degradation test under simulated sunlight irradiation. UV-vis diffuse reflectance spectroscopy analysis, electrochemical impedance test, and the observed transient photocurrent responses prove not only the significant role of Cs2O in extending light absorption to visible and near-infrared regions but also its involvement in charge carrier separation. Radical-trapping experiments verify the direct Z-scheme approach followed by the charge carriers in heterostructured Cs2O-Bi2O3-ZnO photocatalysts. The Z-scheme charge carrier pathway induced by the presence of Cs2O has emerged as the reason behind the efficient charge carrier separation and high photocatalytic activity. Qatar University, Shenzhen Polytechnic, Southern University of Science and Technology, King Fahd University of Petroleum and Minerals, Excellent Young Talents Fund Program of Higher Education Institutions of Anhui Province, Ministry of Science and Technology of the People's Republic of China, National Natural Science Foundation of China Scopus

This article reports the influence of sintering temperature on the structural, dielectric and ferroelectric properties of lead-free Ba0.98La0.01Na0.01TiO3 ceramics synthesized by conventional solid-state reaction technique. The calcination of the ceramic powders has been accomplished using microwave system at 1000 °C for 30 min and sintered at four different temperatures, i.e., 1250, 1300, 1350 and 1400 °C for 4 h. The XRD analysis along with Rietveld refinement confirms that all samples show a single phase tetragonal structure. The confirmation of tetragonal phase structure has been carried out using Raman study. The elemental composition and chemical states of the sintered pellets have been determined using XPS study. The investigation of Scanning Electron Microscopy (FE-SEM) revealed that the grain size increases with rising sintering temperature. The temperature and frequency dependence of dielectric properties has been investigated using Impedance spectroscopy in the frequency range of 60 Hz −1 MHz and temperature range of RT to 150 °C. The Ba0.98La0.01Na0.01TiO3 ceramic sintered at 1350 °C obtains the optimum dielectric constant of 2583 and dielectric loss

The title compounds (2E)-1-(4-2,4-dichlorophenyl)-3-[4-(propan-2-yl)phenyl]prop-2-en-1-one (I) and 2E)-1-(4-fluorophenyl)-3-[4-(propan-2-yl) phenyl]prop-2-en-1-one (II), have been synthesized by the base catalyzed Claisen-Schmidt condensation reaction of 4-(propan-2-yl)benzaldehyde with substituted acetophenones. The synthesized compounds were characterized by FT-IR, elemental analysis and single crystal X-ray diffraction. In I and II, the dihedral angle between the terminal rings are 54.68 (19)° and 53.42 (8)°, respectively. The intra molecular hydrogen bond of the type C H⋯O is observed in both the title compounds. The crystal structure is stabilized through C O⋯π (I) and C F⋯π (II) weak intermolecular interactions. Hirshfeld surfaces analysis computational method was carried to quantify the intermolecular interactions. The 2D finger print plots and electrostatic potential were plotted to evidence the intermolecular interactions.

Biosynthesis of gold nanoparticles (GNPs) is an eco-friendly, cost effective and nontoxic alternative to chemical and physical methods. The microbe which inhabits nearly all surfaces on the earth, an attainment typically attributed to their metabolic adaptability. The organism which resides in gold mines would be having more capability to resist against soluble gold toxicity and produce gold nanoparticles efficiently. In the present study, we report for the synthesis of GNPs by a member of Bacillus subtilis isolated from Hutti gold mine, India. The synthesis of GNPs was observed by a color change from yellow to pink and confirmed by a peak around 545 nm using a UV–visible spectroscopy. The synthesized GNPs were further characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Transmission electron microscopy (TEM). The results show that synthesized GNPs are well dispersed and their size ranges 20–25 nm. The present work is aimed to use green synthesized GNPs as catalyst to degrade Methylene blue (MB) and these GNPs could be used to degrade toxic dyes in the environment.

A new chalcone, 1-(3,4-dimethoxyphenyl)-3-(3-hydroxyphenyl)prop‑2-en-1-one (3), was synthesized, characterized by spectroscopy (IR, 1H, 13C NMR, LC-MS) and single crystal X-ray diffraction method. The compound crystallizes in the monoclinic crystal system (space group C2/c) with unit cell dimensions a = 34.940(6) A, b = 5.4090(9) A, c = 16.668(3) A, β = 108.400(8)°, Z = 8, and V = 2989.1(9) A3. The dihedral angle between the terminal phenyl ring is 16.39 (10)o and intramolecular hydrogen bond of the type C-H…O is observed. The intermolecular hydrogen bonds (O-H…O and C-H…O) and short contacts of the type C-H…π were involved in the crystal structure stabilization. The O-H…O and C-H…O intermolecular hydrogen bond generates R22(18) and R22(14) ring motifs, respectively. The intercontacts in the crystal packing were analyzed using Hirshfeld surfaces method using 2D fingerprint plots and electrostatic potential surfaces. The major intercontact contributing to the Hirshfeld surfaces are found to be from H…H and C…H. In addition, the thermal analysis shows two-step degradation of the 3.

A facile synthetic route and growth mechanism zinc oxide nanogranules (ZnO NGs) have been developed using tween 80 via solvothermal method. Tween 80 act as both reducing and stabilizing agent, which plays a critical role in the formation of ZnO NGs and enhanced the antimicrobial and antioxidant activity of ZnO NGs. The formation of surfactant stabilized ZnO NGs are confirmed by monitoring UV–Vis absorption spectra for surface plasmon resonance (SPR) band observed at ∼364 nm. Further, the band gap from UV–Vis absorption spectra of NGs shows blue shift which is attributed to decrease in particle size of synthesized ZnO NGs. The powder X-ray diffraction (XRD) pattern of ZnO NGs shows well crystalline nature with hexagonal wurtzite structure. The size and surface morphology of as synthesized ZnO NGs were analysed by transmission electron scanning microscopy (TSEM), which confirms the obtained NGs having uniform spherical shape with the sizes ranging from 15 to 20 nm. FTIR results confirmed ZnO NGs bio-capped with functional group of surfactant molecule (tween 80), which stabilizes the NGs for a long time and enhanced the biological activity. In addition, the in vitro biological activity such as antioxidant, antimicrobial and haemolysis were performed to as obtained ZnO NGs. The in vitro antioxidant properties of the granules was performed by using DPPH assay and found that the antioxidant activity of prepared NGs was enhanced to 90% when compared to control. The antimicrobial activity of as synthesized ZnO NGs against selected food-born pathogen revealed that the tested Gram negative bacteria are more pronounced than the tested Gram positive bacteria. The cytotoxic assessment was carried out by hemolytic test shows there was no toxicity found with treated sample. Moreover, photocatalytic degradation of rhodamine B dye was also carried out for ZnO NGs. This study suggested that tween 80 treated ZnO NGs could be used in many biological applications and food science.

Graphene oxide (GO) was reduced using Justichia wynaadensis aqueous extract. GO was mixed with extract and refluxed at 100 °C for 10 h to obtain reduced GO. PXRD of rGO showed broad peak at 2 = 25° and disappearance of 2 = 9.75° after refluxing which indicates efficient removal of oxygen containing groups. SEM images of rGO showed flaky structures typical of retainment of GO structure with folded curtains like appearance of rGO. UV-vis spectra demonstrated absorption band ~300 nm and shoulder at 400 nm corresponding to π–π* transitions and C ═ O bonds respectively indicating that rGO is red shifted due to decrease in oxygen functional groups. rGO showed potent antibacterial activity against Staphylococcus aureus, upon testing against S. aureus and P. aeruginosa. It showed 67% radical scavenging against DPPH at 500 μg/mL concentration. In conclusion, J. wynaadensis aqueous extract efficiently removed oxygen functionalities from GO surface with significant biological activities.

The title compound, C22H23N2BrO2 was synthesized via one-pot reductive cyclization method and characterized by CNH analysis, FT-IR, UV-visible, mass, 1H and 13C NMR spectra, thermogravimetric analysis (TGA) and single crystal X-ray diffraction method. The compound crystallizes in monoclinic crystal system: sp. gr. P21/c, Z = 4. The crystal data reveals that the intermolecular interactions of the C–H···π and π···π type connect the molecules which was also visualized with the help of Hirshfeld surface analysis.

Despite numerous reports have investigated the effect of morphology on the properties of nanomaterials, its role in tuning nanomaterials properties is still not clear to date. This work introduces a unique attempt to explore the correlation among morphology, surface defects (oxygen vacancies), and properties of nanomaterials. To achieve this task, three different morphologies of ZnO nanoflowers were prepared via hydrothermal method by varying the concentration of diethylamine. It was observed that a change in ZnO nanoflowers morphology results in changes in their optical, photocatalytic, and antibacterial properties. Photoluminescence and X-ray photoelectron spectroscopy analyses reveal the presence of oxygen vacancies (VO) in ZnO nanoflowers with a concentration varies with respect to morphology. VO concentration plays a key role in tuning ZnO band gap and the concentration of reactive oxygen species and thereby tuning optical, photocatalytic, and antibacterial properties of ZnO nanoflowers. Our results suggest that VO concentration, morphology, and properties of ZnO nanoflowers are correlated.

This study demonstrated a solvothermal method of growth of three different morphologies of zinc oxide nanoparticles (ZnO NPs): i) flower-like nanorod and nanoflakes, ii) assembled hierarchical structure, and iii) nano granule. Oleic acid (C 18 H 34 O 2 ), gluconic acid (C 6 H 12 O 7 ) and tween 80 (C 64 H 124 O 26 ) were used as surfactant/capping/reducing agent for the formation of different morphologies of nanoparticles. The as-synthesized ZnO NPs were characterized by different physicochemical techniques such as UV–vis (UV–vis) spectroscopy, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) analysis and dynamic light scattering (DLS) studies. Further, the antioxidant and antimicrobial activity of these nanostructures was evaluated. The antioxidant activity of these nanostructures was assessed via 2,2-diphenyl,1-1 picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and H 2 O 2 free radical scavenging activity. The in vitro antimicrobial activity of the obtained nanostructures was demonstrated against both gram negative ( Escherichia coli ) and gram positive ( Staphylococcus aureus ) bacterial genera. This study revealed antioxidant and antimicrobial properties of different structures of ZnO NPs suggesting their biomedical and industrial applications.

Oxygen vacancies (VO) as intrinsic defects play a key role in determining zinc oxide (ZnO) properties. Herein, ZnO nanorods with uniform morphology have been synthesized via hydrothermal method. The obtained nanorods appear semitransparent in SEM images indicating their electron semitransparent nature (ESN). Dye sensitized solar cells (DSSCs) studies reveal the superior electron transport property of the prepared nanorods further confirming their ESN. XPS, optical absorption, and DSSCs results suggest that the origin of ESN is the presence of an appropriate amount of VO in the ZnO nanorods. Moreover, the obtained ZnO nanorods exhibit excellent photocatalytic activity in decomposition of phenol under sunlight irradiation which is attributed to VO. Our study introduces a fundamental insight into the role of VO in inducing ESN as a new property for ZnO.

Carbon nanotubes (CNTs) possess outstanding properties that could be useful in several technological, drug delivery, and diagnostic applications. However, their unique physical and chemical properties are hindered due to their poor solubility. This article review's the different ways and means of solubility enhancement of single-wall carbon nanotubes (SWNTs). The advantages of SWNTs over the multi-walled carbon nanotubes (MWNTs) and the method of non-covalent modification for solubility enhancement has been the key interest in this review. The review also highlights a few examples of dispersant design. The review includes some interesting utility of SWNTs being wrapped with polymer especially in biological media that could mediate proper drug delivery to target cells. Further, the use of wrapped SWNTs with phospholipids, nucleic acid, and amphiphillic polymers as biosensors is of research interest. The review aims at summarizing the developments relating to wrapped SWNTs to generate further research prospects in healthcare.

A new Schiff base (E)-N′-(4-nitrobenzylidene)-2-(1-(4-methoxy-phenyl)-5-oxo-1H-1,2,4-triazol-4(5H)-yl)acetohydrazide (3) was synthesized and characterized by IR, 1H NMR, 13C NMR, Mass spectral data, elemental analysis, TGA/DTA and finally by single crystal X–ray crystallography. X–ray diffraction study indicates that the title compound crystallizes in the monoclinic crystal system (space group P21/n) with unit cell dimensions a = 11.2265(3) A, b = 8.8051(2) A, c = 18.6200(6) A, β = 90.772(2)°, Z = 4, and V = 1840.43(9) A3. The crystal structure is stabilized by intermolecular hydrogen bonds (C H⋯O and N H⋯O) and short contacts of the type C O⋯π. Theoretical calculations of the compound 3 are carried out using density functional theory (DFT) at B3LYP/6–31+G level. Intermolecular interactions in the crystal structures were quantified using the Hirshfeld surface analysis. The majority contribution to the Hirshfeld surface is H⋯O (34.6%) contacts.

The title compound, 1-(3,4-dimethoxyphenyl)-3-(4-bromophenyl) prop-2-en-1-one (1DBr) was synthesized and characterized based on spectroscopic analysis (MS, FT-IR, Elemental analysis, UV–visible, 1H NMR and 13C NMR) and finally the three-dimensional structure is confirmed using single crystal X-ray diffraction studies. The molecule is almost planar and the C---H⋯O intramolecular hydrogen bond closes the ring S(5). In the crystal structure, the molecules are connected through intermolecular hydrogen bond C---H⋯O (R22(14) ring motif) and intermolecular interactions (C---H⋯π and C---O⋯π). Hirshfeld surfaces computational method was employed to quantify the inter-contacts (2D Fingerprint plots) and calculate enrichment ratio (E). The highest value of E is calculated for the contact Br⋯O (1.65) followed by C⋯C (1.02) and have high propensity for forming contacts in the crystal. This provides the basis for the existence of putative halogen bond of the type C--Br⋯O. In addition, the Energy-framework analysis was used to analyze and visualize the 3D-topology of the crystal packing. The dispersion energy framework is dominated over the electrostatic energy-frameworks. The thermogravimetric analysis (TGA) provided the thermal degradation of the 1DBr to be from 230 to 320 °C.

Single crystals of 2-methoxy-4(phenyliminomethyl)phenol were grown from ethanol by slow evaporation solution growth technique. Single crystal X-ray diffraction experiment reveals the crystallization in orthorhombic system having non-centrosymmetric space group C2221. Geometrical optimization by density functional theory method was carried out using Gaussian program and compared with experimental results. Detailed experimental and theoretical vibrational analyses were carried out and the results were correlated to find close agreement. Thermal analyses show the material is thermally stable with a melting point of 159 °C. Natural bond orbital analysis was carried out to explain charge transfer interactions through hydrogen bonding. Relatively smaller HOMO-LUMO band gap favors the non linear optical activity of the molecule. Natural population analysis and molecular electrostatic potential calculations visualize the charge distribution in an isolated molecule. Calculated first-order molecular hyperpolarizability and preliminary second harmonic generation test carried out using Kurtz-Perry technique establish 2-methoxy-4(phenyliminomethyl)phenol crystal as a good non linear optical material. Z-scan proposes the material for reverse saturable absorption.

Pure and alkaline metal ion (Mg, Ca, Sr, Ba) doped Cerium oxide nanostructures were successfully synthesized by hydrothermal method. The structural, optical and compositional studies of the prepared nanoparticles were undertaken by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL), Raman, X-ray photoelectron spectroscopy (XPS) and TEM analyses. The photocatalytic activity of prepared nanoparticles was analyzed using methylene blue dye. XRD pattern reveals that the prepared nanoparticles are polycrystalline nature and there is no any by-product related peaks were observed for the doped samples. The incorporation of dopants into the CeO2 nanoparticles was confirmed through PL, Raman and XPS spectra. The enhanced photocatalytic activity for the alkaline metal doped samples was observed compared to pure cerium oxide nanoparticles.

In this work, a direct Z-scheme Cs2O–Bi2O3–ZnO heterostructure without any electron mediator is fabricated by a simple solution combustion route. Cs2O is chosen as a sensitizer to expand the light absorption range, and in addition, its conduction band minimum (CBM) and valence band maximum (VBM) positions are suitable to construct a direct Z-scheme system with ZnO and Bi2O3. Structural and elemental analyses show clear evidence for heterostructure formation. The Z-scheme charge carrier migration pathway in Cs2O–Bi2O3–ZnO is confirmed by high resolution XPS and ESR studies. The fabricated heterostructure exhibits a good ability to split water to H2 and O2 under simulated sunlight irradiation without any sacrificial agents or co-catalysts and has excellent photostability. The apparent quantum efficiency of the optimized Cs2O–Bi2O3–ZnO heterostructure reaches up to 0.92% at 420 nm. The excellent efficiency of this fabricated heterostructure is attributed to the efficient charge carrier separation, the high redox potential of the CBM and VBM benefiting from a direct Z-scheme charge carrier migration pathway and the extended light absorption range.

In this work, cerium oxide (CeO2) nanostructures have been synthesized using a sunlight-assisted combustion method from cerium nitrate hexahydrate and glycine as precursors. The synthesized sunlight-assisted cerium oxide (CeO2-SA) nanopowder has been characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscope, UV–Visible spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, and Nitrogen adsorption–desorption isotherm. In this method of synthesis, natural sunlight is used as energy source to ignite the reaction and the product is obtained immediately. The synthesized CeO2-SA has a fluorite-like cubic crystal structure and spongy morphology with irregular pores. It is also found that CeO2-SA possesses a smaller particle size, narrower band gap and lower recombination rate than bulk CeO2. The crystalline size of CeO2-SA nanoparticles was obtained to be 4.9 nm. The optical band gap for CeO2-SA was found to be 2.98 eV. The BET Surface area for CeO2-SA was found to be 19.7 m2/g which is 5.3 times greater than the surface area of bulk CeO2 (3.7 m2/g). Around 91% degradation of methylene blue dye (MB) is observed. Therefore, CeO2-SA exhibits higher photocatalytic efficiency towards the degradation of MB than bulk CeO2.

Retraction Note: The Editor-in-Chief has retracted this article [1] because it significantly overlaps with a previously published article from the same authors [2]. Yallappa Sangappa disagrees with this retraction. The other authors have not responded to correspondence regarding this retraction.