Diode characteristics, piezo-photocatalytic antibiotic degradation and hydrogen production of Ce3+ doped ZnO nanostructures.

Piezo-photocatalysis of ZnO nanostructures had recently well attracted due to their exceptional potential in degrading the antibiotics and scalable hydrogen production. Here, we have synthesized the Ce3+ doped ZnO nanospheres in a facile wet chemical strategy. Dopant ions induced morphological evolution and optical bandgap tuning had observed in our experiment. Optical absorbance spectrum had confirmed the bandgap shortening occurs with Ce3+ doped ZnO specimens. The bandgap gap value had reduced to 2.82 eV from 3.05eV confirming the visible light responsivity of ZnO nano specimens. Obtained Zn(1-x)CexO nanospheres were utilized to fabricate the p-Si/n- Zn(1-x)CexO heterojunction diodes as well studied the improved electrical conductivity for the Ce3+ specimen-based diodes. Besides, ideality factor and barrier height values of the heterojunction diodes ZnO/p-Si, Zn0.99Ce0.01O/p-Si, Zn0.97Ce0.03O/p-Si, and Zn0.95Ce0.05O/p-Si are 15.97 & 0.43 eV, 15.47 & 0.44 eV, 8.02 & 0.46 eV and 5.21 & 0.47 eV, respectively. Direct sunlight assisted piezo-photocatalytic tetracycline (TC) degradation efficiency of ZnO, Zn0.99Ce0.01O, Zn0.97Ce0.03O, and Zn0.95Ce0.05O nanostructures respectively are 64%, 69%, 74% and 82%. We have produced the hydrogen quantity of 1234 µ mol h-1, 1490 µ mol h-1, 1750 µ mol h-1 and 1980 µ mol h-1 with 0%, 1%, 3% and 5% Ce3+ doped ZnO specimens under the direct sunlight assisted piezo-photocatalytic H2 production from H2S splitting.

Impact of piezoelectric effect on the heterogeneous visible photocatalysis of g-C3N4/Ag/ZnO tricomponent.

In recent years, the piezophotocatalytic mechanism had been intensively recognized as a potential and promising route to sewage treatment. Here we report the piezoelectric effect improved heterogeneous photocatalysis of g-C3N4/Ag/ZnO (g-CN/A/Z) tricomponent in rhodomine B (RhB) degradation. Initially, the nanomaterials were characterized for their physico-chemical and optoelectronic properties using analytical techniques such as x-ray diffraction (XRD), scanning & transmission electron microscopes (SEM & TEM), UV-vis spectrophotometer and photoluminescence spectroscopy (PL). In addition, the photoelectrochemical activity of determining the photocurrent density and electrochemical impendence response were also been conducted. The catalytic properties of the tricomponent, g-CN/A/Z was studied with the degradation of RhB with visible photons irradiation and ultrasonication. In piezophotocatalysis, degradation up to 89% of RhB was achieved with 1.26 folds synergetic effect on par to the photocatalysis and piezocatalysis.

Au integrated 2D ZnO heterostructures as robust visible light photocatalysts.

Integration of semiconducting nanostructures with noble metal nanoparticles are turning highly desirable for cost efficient energy and environmental related applications. From this viewpoint, we report on a facile aqueous synthesis of polymer capped gold (Au) nanoparticles on free standing 2D layered structures of zinc oxide (ZnO) to result with ZnO/Au nanocomposites. Concentration of Au nanoparticles were observed to promote the preferential growth of ZnO along the (002) wurtzite plane. The ZnO/Au structures and their morphological dissemination was noted to be of few. This flake like structure was also noted to be greatly influenced by the concentration of Au in the colloidal blend. Optical band edge transformations noted in the absorption spectra across the lower wavelength region and the shift in surface plasmon resonance (SPR) towards the red region of the visible spectrum signify the improved absorptivity of the heterostructures along the visible spectrum. These heterostructures exhibited remarkable visible light driven photocatalytic activity (99% efficiency) on par with pristine ZnO. The findings also attest this new class of composite structures to open up new openings in diversified solar energy conversion related functions.

Breast Cancer Targeted Treatment Strategies: Promising Nanocarrier Approaches.

Breast cancer is the second most common cancer that causes death among women worldwide. Incidence of breast cancer is increasing worldwide, and the age at which breast cancer develops has shifted from 50- 70 years to 30-40 years. Chemotherapy is the most commonly used effective treatment strategy to combat breast cancer. However, one of the major drawbacks is low selective site-specificity and the consequent toxic insult to normal healthy cells. The nanocarrier system is consistently utilised to minimise the various limitations involved in the conventional treatment of breast cancer. The nanocarrier based targeted drug delivery system provides better bioavailability, prolonged circulation with an effective accumulation of drugs at the tumour site either by active or passive drug targeting. Active targeting has been achieved by receptor/protein anchoring and externally guided magnetic nanocarriers, whereas passive targeting accomplished by employing the access to the tunnel via leaky tumour vasculature, utilising the tumour microenvironment, because the nanocarrier systems can reduce the toxicity to normal cells. As of now a few nanocarrier systems have been approved by FDA, and various nanoformulations are in the pipeline at the preclinical and clinical development for targeting breast cancer; among them, polymeric micelles, microemulsions, magnetic microemulsions, liposomes, dendrimers, carbon nanotubes, and magnetic Nanoparticles (NPs) are the most common. The current review highlights the active and passive targeting potential of nanocarriers in breast cancer and discusses their role in targeting breast cancer without affecting normal healthy cells.

Cytotoxic potentials of biologically fabricated platinum nanoparticles from Streptomyces sp. on MCF-7 breast cancer cells.

Biosynthesis of novel therapeutic nano-scale materials for biomedical and pharmaceutical applications has been enormously developed, since last decade. Herein, the authors report an ecological way of synthesising the platinum nanoparticles (PtNPs) using Streptomyces sp. for the first time. The produced PtNPs exhibited the face centred cubic system. The fourier transform infrared spectrum revealed the existence of amino acids in proteins which serves as an essential reductant for the formation of PtNPs. The spherical morphology of the PtNPs with an average size of 20-50 nm was observed from topographical images of atomic force microscopy and field emission scanning electron microscopy. The X-ray fluorescence spectrum confirms the presence of PtNPs with higher purity. The PtNPs size was further confirmed with transmission electron microscopy analysis and the particles were found to exist in the same size regime. Additionally, PtNPs showed the characteristic surface plasmon resonance peak at 262 nm. Dynamic light scattering studies report that 97.2% of particles were <100 nm, with an average particle diameter of about 45 nm. Furthermore, 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-tetrazolium assay based in vitro cytotoxicity analysis was conducted for the PtNPs, which showed the inhibitory concentration (IC50) at 31.2 µg/ml against Michigan Cancer Foundation-7 breast cancer cells.

Colloidal synthesis and electrical behaviour of n-ZnGdO/p-Si heterojunction diodes.

Studies on manoeuvring the optoelectronic characteristics of a semiconducting nanostructure are of recent specific interest for a wide range of photonic applications. In this regard, the optical and electrical characteristics of ZnO nanostructures have been tuned and studied systematically using Gd ions. The structural and morphological characteristics of the solution processed ZnGdO nanostructures were studied in detail using the results of X-ray diffraction and microscopic measurements. The absorption band edge in ZnO was noted to shift towards the lower wavelength values on Gd substitution, suggesting an increase in its energy band gap. The blue emissivity from ZnO complexes was also noted to improve as a function of Gd composition in ZnO. The potential of ZnGdO nanostructures for optoelectronic functions was evaluated by fabricating heterojunction diodes based on n-ZnGdO/p-Si. The diode characteristics revealed an improved electrical conductivity and rectifying behaviour from the fabricated architectures upon Gd substitution and photon illumination. The findings are correlated with the increased charge carrier concentration and defect states existing within ZnGdO species, through appropriate mechanisms.