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Al-doped ZnO nanoparticles (n-AZO) were synthesized by sol-gel method and tested their photocatalytic degradation of MB under visible light irradiation. The micro-structural and optical properties of n-AZO were evaluated from XRD, FE-SEM, HR-TEM, SAED, FTIR and UV–Vis techniques. The presence of Al in ZnO lattice was confirmed from EDAX-mapping, and XPS-elemental analysis. XRD-peak profile analysis and SAED pattern of n-AZO confirmed the substitution of Al3+(0.53 A) on to Zn2+(0.73 A) sites without changing the hexagonal structure of ZnO. The particular dopant concentration of Al-ions (Al = 5 at.%) revealed the superior visible light photocatalytic degradation of MB due to decreasing the particle size and increasing the catalytic functional sites. The highest photocatalytic degradation of MB was achieved to be ∼94% within 60 min and showed the remarkable degradation of the organic pollutant under the illumination of visible light.

The present paper reports the effect of Graphene Nanoribbons (GNRs) for improving the dehydrogenation of MXH 4 , where M = Na , Li and X = Al , B through density functional calculations. The rectangular Armchair GNRs and ZigZag GNRs with width up to 7.57 A & 10 A and length of 15 A &10 A respectively were considered for the investigation. The effect of dopant and defect was introduced by doping with different dopants ( B , N , Al , Cl and F) and introducing vacancy defect respectively. The MXH 4 interacts with the surface atoms of GNRs with binding energy from 0.31–0.89 eV with AGNR and from 0.26 eV to −1.42 eV with ZGNR respectively. Charge transfer of 0.12–0.26 e take place from GNR surface to MXH 4 molecule resulting in significant decrease in hydrogen release energy ( E HRE ). Doped and defective AGNR lowers E HRE of MXH 4 sharply by 19–56% whereas ZGNR decreases E HRE by 18–70% respectively. The results agree qualitatively with the available experimental result and outline the importance of nano carbon as a catalyst for improving the performance of light complex metal hydride systems.

With the support of research projects focusing on sampling and data analysing of different varieties of chemical compounds, wavelength dispersive X-ray fluorescence (WDXRF) technique is commonly used in many research laboratories throughout the world wide to determine the elemental composition of various unknown samples. In the present study, first time we have employed polychromatic S8 TIGER WDXRF spectrometer to study the chemical state analysis in Cl Kα and Kβ1,3 X-ray emission lines. A Voigt function is used to determine the central peak position of the K shell emission lines in all samples. From the present measurements, it is seen that both positive and negative shifts have been observed in Cl Kα (2.622 keV) and Kβ1,3 (2.817 keV) emission peaks. It has been also seen that the effective charge, relative line-width and relative intensity ratio I(Kβ1,3/Kα) are found proportional with the chemical shift. Furthermore, a parabolic relation is also established between them.

The present paper reports the effect of B- and BN-doped $$\hbox {C}_{60}$$ as catalysts for lowering the dehydrogenation energy in $$\hbox {MXH}_{4}$$ clusters (M = Na and Li, X = Al and B) using density functional calculations. $$\hbox {MXH}_{4}$$ interacts strongly with B-doped $$\hbox {C}_{60}$$ and weakly with BN-doped $$\hbox {C}_{60}$$ in comparison with pure $$\hbox {C}_{60}$$ with binding energy 0.56–0.80 and 0.05–0.34 eV, respectively. The hydrogen release energy $$(E_{\mathrm{HRE}})$$ of $$\hbox {MXH}_{4}$$ decreases sharply in the range of 38–49% when adsorbed on B-doped $$\hbox {C}_{60}$$ ; however, with BN-doped $$\hbox {C}_{60}$$ the decrease in the $$E_{\mathrm{HRE}}$$ varies in the range of 6–20% as compared with pure $$\hbox {MXH}_{4}$$ clusters. The hydrogen release energy of second hydrogen atom in $$\hbox {MXH}_{4}$$ decreases sharply in the range of 1.7–41% for BN-doped $$\hbox {C}_{60}$$ and decreases in the range of 0.2–11.3% for B-doped $$\hbox {C}_{60}$$ as compared with pure $$\hbox {MXH}_{4}$$ clusters. The results can be explained on the basis of charge transfer within $$\hbox {MXH}_{4}$$ cluster and with the doped $$\hbox {C}_{60}$$ .

Purpose The purpose of this paper is to design a low-cost stress bimorph RF-MEMS switch which is the desired transmission area application. Design/methodology/approach The bimorph structure of the low-temperature plasma-enhanced chemical vapor deposition (PECVD) of thermal oxide and gold are utilized to create the vibrating membrane. The effects of process conditions of low-temperature oxide deposited using the PECVD technique enable stress-free deposition of the key structural layer. Findings Scanning electron microscope images of the RF micro-switch confirms negligible stress in the released structure. The RF performances of this device exhibit isolation around 43 dB of up to 50 GHz in the OFF-state position and an insertion loss of less than 0.18 dB in the ON-state. Originality/value The finite element method results show good isolation of 43 dB and less insertion loss of 0.18 dB.

The KL 2,3 and L 3 M 4,5 radiative resonant Raman scattering (RRS) cross sections have been measured for the quasimonochromatic Mn K α 1,2 X-rays (5.895 keV) in 24 Cr ( K -shell level width (Γ K ) =1.08 eV) and 59 Pr ( L 3 -subshell level width (Γ L3 ) =3.60 eV), respectively, using targets in metallic and various chemical forms. The incident Mn K α 1,2 X-ray energy is lower than the K-shell binding energy of 24 Cr and L 3 -subshell binding energy of 59 Pr by ~94 Γ K (Cr) and ~94 Γ L 3 (Pr), respectively. The experimental measurements were performed with a low energy Ge detector (LEGe) and a radioactive 55 Fe annular source in conjunction with 24 Cr absorber. The measured cross section values for the 24 Cr and 59 Pr elements in their various oxidation states are found to be same within experimental errors. The measurements were further extended to investigate alignment of the intermediate L 3 -subshell ( J =3/2) virtual vacancy states in 59 Pr through angular distribution measurements for RRS photon emission, which is found to be isotropic within experimental errors.

Using first principal calculations we have investigated the change in electronic and structural properties of CO, NO, CO2, and NO2 adsorbed on the ultra thin graphene nanoribbons (GNRs) with armchair and zigzag edges. Gas molecules interacts weakly with GNRs with adsorption energy of -0.07eV, -0.13eV, -0.56eV and -0.32eV for CO, NO, CO2, and NO2 respectively. The charge transfer take place from GNR to CO, CO2 and NO2 molecules while NO act as donor to GNR. Results show that armchair GNR is more sensitive to adsorption of NO2 as compare to CO, NO and CO2.

Carbon nanotubes (CNTs) improve the dehydrogenation kinetics of NaAlH 4 . The present paper reports the effect of small diameter CNTs for lowering the dehydrogenation energy from NaAlH 4 cluster using Density functional theory. Pristine carbon nanotubes (P-CNTs) with Zig-Zag (n, 0) and Armchair (n, n) chirality with n = 3, 4, 5; chemically B/N doped CNTs (C-CNTs) and CNTs with vacancy defect (V-CNTs) are considered systematically to study the interaction with NaAlH 4 cluster. NaAlH 4 interacts with P-CNTs, C-CNTs and V-CNTs with binding energy of the order 0.77–0.98 eV, 0.60–1.01 eV and 0.81–1.74 eV respectively. The hydrogen release energy of NaAlH 4 decreases from 3.95 eV by 38%, 49% and 39% when interacting with P-CNTs, C-CNTs and V-CNTs respectively. Results can be explained on the basis of electronic charge transfer and redistribution between CNTs and NaAlH 4 which weaken the bonds involved in cluster and enhance easy removal of hydrogen. The results are in agreement with the available experimental data.

We studied the nucleation and growth of TiO2 nanoflowers and carbon nanotubes-TiO2 nanocomposite (n-CNT-TiO2) by the hydrothermal method in a single step at 150 °C and tested them for the photocatalytic degradation of MB. The microstructural analysis confirmed the transformation of TiO2 nanoflowers to CNT-TiO2 spheres due to the role of surface energy of CNT. The XRD peak profile analysis of TiO2 and n-CNT-TiO2 confirmed the formation of pure rutile phase of Titania sintered at 400 °C. A red-shift in the bandgap of n-CNT-TiO2 nanocomposite (2.7eV) was observed due to the donor states towards the conduction band edge. The core-level of XPS showed the strong interaction between carbon and titanium atoms. The CNT facilitate the interfacial charge transfer or avoid the formation of charge recombination due to the variation of Ti4+ to Ti3+ sites. The highest photocatalytic degradation was achieved by using the photocatalyst of n-CNT-TiO2 nanocomposite. The incorporation of CNT provides the interfacial charge transfer facility that creates new interbands energy states for the delay of electron-hole recombination, which cater the environmental remediation.

Nanoconfinement improves dehydrogenation kinetics of complex metal hydrides. The present paper reports effect of confinement of MXH4, where M = Na, Li and X = Al, B inside carbon nanotubes (CNTs) (n, 0) n = 9–11 chirality and diameter of 7.47 A, 7.87 A, 8.73 A, respectively, using Density Functional calculations. The MXH4 interacts strongly with the surface atoms of CNT (11, 0) and is found to be the smallest stable system for confinement of MXH4 clusters. The Hydrogen release energy (E Hre) of NaAlH4 decreases sharply by , w.r.t. pure NaAlH4 cluster when confined inside CNT(11, 0). Similarly, in CNT (11, 0) E Hre decreases by for LiAlH4, for NaBH4 and for LiBH4. Thus, resulting confinement had a profound effect in improving the energetics of complex metal hydride nanoparticles without catalyst.

We present the results of systematic investigation into size dependent electronic and magnetic properties of ultra thin graphene nanoribbons (GNRs) of finite and infinite length using spin polarized density functional calculation. The rectangular GNRs with width up to 1.40 nm with finite (2.50 nm) and infinite length were investigated. The ultra thin GNRs are found less stable in comparison to larger GNRs with binding energy increasing with increase in the size. All GNRs have shown finite HOMO-LUMO gap which decreases oscillatory as a function of width. HOMO-LUMO gap in the Finite length armchair GNRs is in range of 0.01–0.36 eV, where as in infinite length GNR the energy gap is in the range of 0.30–1.41 eV. Zigzag GNRs have shown very small HOMO-LUMO gap in the range 50–80 meV. The zigzag GNR have shown opening of energy band gap. However, for N = 8 and 10 layers, GNRs with zigzag edges are found to be ferromagnetic. The edge C atom on zigzag edges contribute magnetic moment of 0.94 per C atom with total magnetic moment remaining constant with increase in the width. The energy difference between ferromagnetic and anti-ferromagnetic state decreases sharply with the increase in GNR width suggesting iso-energetic behavior in larger GNRs. The results are consistent with the reported experimental results.