Density functional theory calculations and Hirshfeld surface analysis of propyl-para-hydroxybenzoate (PHB) for optoelectronic application

The geometries, electrostatic potential, Mulliken charge analysis, Natural Bond Orbital analysis and polarizabilities of propyl-para-hydroxybenzoate were calculated using B3LYP functional with 6-311++G(d,p) basis set. The calculated geometries are well matched with the experimental values. The Mullliken atomic charge analysis shows that the eventual charges are contained in the molecule. The NBO analysis explains the intramolecular charge transfer in the PHB molecule. The bonding features of the molecule were analyzed with the aid of Hirshfeld surface analysis. The frontier molecular orbital analysis showed the charge transfer obtained within the molecule. The calculated hyperpolarizability of the PHB molecule was 6.977E −30 esu and it was 8.9 times that of standard urea molecule

The growth of benzophenone crystals by Sankaranarayanan-Ramasamy (SR) method and slow evaporation solution technique (SEST): A comparative investigation

Longest unidirectional benzophenone (BP) crystal having dimension of 1060 mm length and 55 mm diameter was grown by Sankaranarayanan-Ramasamy method. The growth rate was measured by monitoring the elevation of the crystal-solution interface at different temperatures. The high resolution X-ray diffraction and etching measurements indicate that the unidirectional grown benzophenone crystal has good crystalline perfection and less density of defects. The optical damage threshold of SEST and SR grown BP crystals has been investigated and found that the SR grown benzophenone crystal has higher laser damage threshold value than the conventional method grown crystal. Microhardness measurement shows that crystals grown by SR method have a higher mechanical stability than the crystals grown by SEST method. Dielectric permittivity and birefringence are high in SR grown crystal compared to SEST grown BP crystal. The UV-vis-NIR results show that SR method grown crystal exhibits 7% higher transmittance as against crystals grown by conventional method

Characterization of 〈0 1 0〉 directed KAP single crystals grown by Sankaranarayanan–Ramasamy (SR) method

Single crystals of potassium acid phthalate (KAP), a semi-organic compound, have been grown at an average growth rate of 4 mm/day from aqueous solution by using the uniaxial crystal growth method of Sankaranarayanan–Ramasamy (SR). Transparent, cylindrical KAP crystal of size 70 mm length and 15 mm diameter was grown. The grown crystals were characterized by etching and UV–vis NIR analysis. HRXRD analysis indicates that the crystalline perfection of SR method-grown KAP is good. The KAP crystals grown by SR method have 9% higher transmittance than conventional method-grown crystal. The microhardness test was carried out on the (0 1 0) face and a load-dependent hardness was observed. TG–DTA evaluated the thermal properties of the grown crystal. KAP was found to be thermally stable up to 290 °C. The dielectric constant and dielectric loss of the crystal were studied as function of frequency and temperature

Facile synthesis of tungsten carbide nanorods and its application as counter electrode in dye sensitized solar cells

Tungsten carbide nanorods (WC-NRs) are synthesized by pseudomorphic transformation of chemically synthesized W3O8 nanorods using a high-temperature method. The WC-NRs was introduced into dye sensitized solar cell (DSSC) as counter electrode (CE) catalyst to replace the expensive platinum (Pt). The synthesized WC-NRs were characterized by field emission scanning electron microscopy (FESEM), BET surface area analysis and powder X-ray diffraction (PXRD) measurements. The electrochemical properties of WC-NRs counter electrode were studied using electrochemical impedance spectroscopy (EIS) techniques. The photovoltaic performance of the DSSC with WC-NRs counter electrode was evaluated under simulated standard global AM 1.5G sunlight (100 mW/cm2). The solar to electrical energy conversion efficiency (η) of the WC-NRs with binder and binder free based DSSC was found to be 1.92% and 0.59% respectively. The cell performance can be attributed to the WC-NRs network, catalytic redox activity and 1-D efficient charge-transfer network. Such WC-NRs configuration as CE provides a potential feasibility for counter electrodes in DSSC applications

Investigations of tungsten carbide nanostructures treated with different temperatures as counter electrodes for dye sensitized solar cells (DSSC) applications

Tungsten carbide (WC) materials are synthesized and sintered at 800, 900 and 1000 °C. The differently treated tungsten carbide nanostructures (WC-NSs) have been investigated as counter electrode (CE) catalysts to replace the expensive platinum (Pt) for dye sensitized solar cells (DSSC) towards better power conversion efficiency. The synthesized samples were structurally characterized by powder X-ray diffraction (PXRD) which reveals that the sintering temperatures strongly affect the structure of WC-NSs. The surface morphology and chemical compositions were examined by scanning electron microscope (SEM) fitted with energy dispersive X-ray analysis (EDAX). The electrochemical studies of WC-NSs suggest that increasing the sintering temperature leads to increase in the charge transfer resistance and results in decrease of the catalytic activity of the WC-NSs CE. The power conversion efficiency of the WC-NSs materials sintered at 800 °C is higher than that of 900 °C and 1000 °C sintered materials. It is found that the photovoltaic performance was strongly affected by the sintering temperature of the WC-NSs materials. The tungsten carbide nanorods sintered at 800 °C showed better photovoltaic parameters such as Jsc, Voc, FF and η of 2.71 mA cm−2, 0.53 V, 0.28 and 0.41 %, respectively when compared to the WC-NSs sintered at 900 and 1000 °C. The optimally modified WC-NSs could be a useful substitute

Directional growth, physicochemical and quantum chemical investigations on pyridinium 2-carboxylate: 4-nitrophenol (P2C4N) single crystal for nonlinear optical (NLO) applications

An organic nonlinear optical (NLO) single crystal of pyridinium 2-carboxylate: 4-nitrophenol (P2C4N) was grown by the Sankaranarayanan-Ramasamy (SR) method using the (1 1 -1) plane. A transparent crystal of size 180 mm in length and 10 mm in diameter was grown over a period of 60 days. The lattice parameters and the molecular structure of the grown crystal were confirmed by single crystal XRD and nuclear magnetic resonance (NMR) spectrum analysis, respectively. The crystalline perfection of the SR method-grown crystal was evaluated by HRXRD analysis; from the observed results, it is evident that the crystal quality is quite good. UV-Vis-NIR analysis shows that the SR method-grown crystal has good transparency (90%) in the visible and NIR regions. The band gap of the title crystal was estimated by the Tauc's plot method and was found to be 3 eV. The title material is thermally stable up to 141 degrees C, and it demonstrates positive photoconductive behaviour. Vickers microhardness studies revealed that the grown crystal can be categorized as a soft material. The laser damage threshold of P2C4N was found to be 2.9 GW cm(-2), which shows that the grown crystal possesses excellent resistance to high power radiation. Z-Scan studies proved that the grown crystal possesses self-defocusing effects and negative nonlinearity. The theoretical spectra were calculated using the B3LYP/cc-pVTZ basis set and were compared with the experimental FT-IR and FT-Raman spectra of the title molecule. The full vibrational assignments of the observed spectra have been proposed by normal coordinate analysis (NCA) followed by force-field calculations. Quantum chemical studies, such as optimized geometry, HOMO-LUMO, natural bonding orbital (NBO) analysis, AIM analysis, hyperpolarizability and molecular electrostatic potential (MEP) were performed for the title molecule. The results are discussed in detail

Expression of Metallothionein, P53 and Antioxidant Enzymes by Selenium and Vitamin D3 during Diethyl Nitrosamine-Induced Rat Liver Preneoplasia: Effect of selenium on nitrosamine-induced rat liver preneoplasia

Many studies have proved that the dietary micronutrient has an inhibitory effect against experimentally induced rat hepatocarcinogenesis. The present work is an attempt to understand combined effect of selenium (Se) and vitamin D3 (vit D3) on some potential protein expression markers of carcinogenesis, such as metallothionein (MT), P53 and antioxidant levels during diethyl nitrosamine (DEN) induced (200mg/kg in 0.9% NaCl; IP) rat liv er preneoplasia. In a short term regimen combined supplementation of Se and vit D3 at a dose of 8 ppm in water and 0.3 μl/100μl in propylene glycol, respectively, suppressed the formation of DNA comets (28.40%), thereby indicating its non- genotoxicity at this particular dose. Se and vit D3 administration throughout the study reduced relative liver weight. Modular incidence were 22.7% when compared to the carcinogen control. However, treatment with Se and vit D3 showed significant expressions of MT and P53 which studied at four sequential time points. An increased immunopositive of P53 protein (1.3±0.56% p<0.02) was found in Se and vit D3 together treated rat liver with an elevated apoptotic labeling index (A1; p<0.001) as documented by TUNEL assay. The positive results of MT expression at various time intervals suggest that, Se and vit D3 together mediated suppression of MT may be associated with induction of apoptosis. The results thus provide evidence for the first time in support of thepotential role of combined supplementation of Se and vit D3 on induction of P53 apoptosis with concurrent suppression of MT in order to have an understanding. Regardless of the mechanism, based on the results reported in this study, both Se and vit D3 could be considered a potential cancer chemopreventive agents whose effect is presumably based on inhibition of growth of the neoplastic cells by coordinated regulations of different biochemical markers and enzymes studied herein