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Abstract: Development of non‐noble metal photocatalysts for hydrogen (H2) generation from renewables is important towards cost effective technology. Titania nanorods with different phase compositions and surface areas were fabricated by calcination of hydrogen titanate (H2Ti3O7) precursors obtained by treating P25 (TiO2) hydrothermally in 10 M NaOH and followed by HCl washing. Subsequently the copper and nickel hydroxides were co‐deposited over TiO2 nanorods and used to generate H2 from alcohol‐water mixtures under UV light. Among the synthesized materials, the optimized photocatalyst 0.8Cu(OH)2‐0.2Ni(OH)2/TNR130‐400 showed very high H2 production rates that are 26.6 mmol h−1g−1 in 20 vol.% ethanol‐water mixture and 35.1 mmol h−1g−1 in 5 vol.% glycerol‐water mixtures. The amount of this H2 production is even higher than obtained from noble metal supported TiO2 photocatalysts. This exceptional photocatalytic H2 production is attributed to the high synergism among nanords mophology of support and in situ formation of Cu and Ni exclusively in metallic states during photoreactions. [ABSTRACT FROM AUTHOR]

Background: The approval of direct acting anti-viral drugs has expanded the treatment access to all patient populations including elderly patients, who were previously neglected. We evaluated the response and tolerability of sofosbuvir plus daclatasvir in old age patients >60 year infected with HCV. Methods: In this prospective observational study, 100 patients were enrolled and were divided into two groups: aged 60–69 (group A) and aged 70 and older (group B). All the patients were given sofosbuvir plus daclatasvir. Sustained virologic response at 12 weeks was the primary endpoint. Response and tolerability of treatment were analysed and compared between these patient groups. Results: Hundred patients aged ≥60 years were treated with sofosbuvir plus daclatasvir. Sustained virologic response rate was 91% in group A (aged 60– 69 year) and 87.8% in group B (aged 70 year and older). No significant adverse effect was noted in both groups. No treatment discontinuation was encountered. Conclusions: Direct acting antiviral drug therapy is highly efficacious and safe for the treatment of HCV in older adults. [ABSTRACT FROM AUTHOR]

Molecular structure of a diol-terminated Schiff base, 4-((4-(4-(3-ethoxy-4- hydroxybenzylideneamino)phenoxy)phenylimino)mriethyl)-2-ethoxyphenol (SB) was studied by single-crystal X-ray diffraction and calculated by using the density functional theory (DFT) method with 6-31G (d) basis set. SB crystallizes in a Tetragonal system in the I41/a space group. The crystal structure is mediated by the ethanol as solvent molecules. The thermal analysis data shows that the SB is stable upto ca. 372 °C. The calculated molecular geometries and the vibration frequencies in the ground state have been compared with the experimental data. The results show that the optimized geometries can reproduce well the crystal structural parameters, and the theoretical vibration frequencies show good agreement with the experimental data, although the experimental data is slightly different from the theoretical ones due to the intermolecular forces. Besides, the molecular electrostatic potential (MEP) and the frontier molecular orbital (FMO) analysis of the compounds were investigated by theoretical calculations. Molecular docking along with the quantitative structure activity relationship (QSAR) investigations showed groove binding as a preferred mode between SB- double stranded DNA(PDB ID-1BNA). Binding strength indicated worthy correlation with various physicochemical parameters like hydrophobic surface area (Vsurf), EHOMO, ELUMO, log P and molar refractivity (MR). Formation constant (Kf) showed good binding strength for SB-DNA complex, thus, could be studied further as anticancer drugs. [ABSTRACT FROM AUTHOR]

Highlights from the article: The potassium metal ion is forming a bond with a nitrogen atom of azine nitrogens, Potassium metal ion is forming seven bonds through K(1)-S(3)#3 3.2481(14) N(1)#2-K(1)-S(3)#3 142.11(8) K(1)-S(1)#1 3.3129(14) O(1)-K(1)-S(1)#1 148.10(8) K(1)-S(1) 3.3475(14) C(1)-S(1)-K(1) 96.04(13).

[Display omitted] • Transition metal nitrides (TMNs) have gained substantial interest to catalyse water splitting reaction. • Iron and nickel based TMNs are considered as ideal electrocatalysts because of the abundance, low cost, and high catalytic activity. • Single phase TMNs have unsatisfactory performance due to inadequate M−H/M−OH bond strength. • Recent developments pertaining to Fe and Ni-based TMNs are presented for electrochemical water splitting. Transition metal nitrides (TMNs) have gained substantial interest to generate hydrogen from direct dissociation of water via catalytic strategy. Due to the unique noble metal like structure, high electric conductivity, corrosion resistance, broad pH stability and probable structural modifications TMNs are gauged as efficient hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and overall water splitting (OWS) electrocatalysts. Iron and nickel based TMNs are considered as ideal electrocatalysts because of the abundance, low cost and high catalytic activity as compared to the expensive benchmark catalysts. However, the single phase TMNs have unsatisfactory performance due to inadequate M−H/M−OH bond strength. Most researchers have focused in designing advanced heterostructures by doping other metals, metallic compounds, and conductive substrates to improve catalytic performance due to the tailored electronic structure to modify M−H/M−OH bond strength, boost electrochemical stability and synergistic effects. In this review, we highlight the recent developments pertaining to Fe and Ni-based TMNs from the stance of advanced nanoarchitecture electrocatalysts for electrochemical water splitting. The key challenges and future perspectives confronting expansion of water splitting catalysts are critiqued. [ABSTRACT FROM AUTHOR]

Non-noble metal containing catalysts for oxygen reduction reaction (ORR) are being targeted due to their low cost and availability. The rarity, high-cost, and self-poisoning of noble metals are the main drawbacks for the large-scale applications. Herein, a facile and simple synthetic strategy is adopted to prepare non-noble metal-based nitrogen doped carbon nanotubes (N-CNTs). The cobalt oxides (CoOx) nanoparticles are in-situ encapsulated inside these N-CNTs which are then treated with acid (HCl) and phosphidized to obtain CoOx-CoP/N-CNTs. High resolution transmission electron spectroscopy (HR-TEM) results reveal that the ends of N-CNTs are closed with nanoparticles. X-ray photoelectron spectroscopy (XPS) confirms the presence of cobalt oxide and cobalt phosphide nanoparticles. The catalyst CoOx-CoP/N-CNTs2 demonstrated E onset and E 1/2 of 0.96 V and 0.81 V, respectively in alkaline environment which is very much comparable to the state of art catalyst (20 wt% Pt/C). Acid treatment significantly enhances the electrocatalytic activity for ORR in comparison to material synthesized without prior treatment with acid. The catalyst exhibits excellent durability over 10,000 cycles and methanol tolerance to 0.5 M methanol addition. The enhanced ORR activity is attributed to synergistic effect of carbon matrix and encapsulated nanoparticles. • Cobalt oxides (CoOx) nanoparticles are in-situ encapsulated inside N-CNTs. • CoOx/N-CNTs treated with acid (HCl) and phosphidized to obtain CoOx-CoP/N-CNTs. • High resolution transmission electron spectroscopy results reveal that the ends of N-CNTs are closed with nanoparticles. • CoOx-CoP/N-CNTs2 demonstrated E onset and E 1/2 of 0.96 V and 0.81 V, respectively in alkaline environment. • The catalyst exhibited excellent durability over 10,000 cycles and methanol tolerance to 0.5 M methanol addition. [ABSTRACT FROM AUTHOR]

Research on water splitting reaction is on priority to explore an alternative source of energy with little to no carbon emissions. Among the two half reactions of electrochemical water splitting, oxygen evolution reaction (OER) is highly desirable yet challenging to prepare a cost effective and viable electrocatalyst to boost the OER activity. Herein, we have prepared a novel electrocatalyst, CoO x -CoP/N-CNTs, by the phosphidization of cobalt oxides (CoO x) encapsulated N- doped carbon nanotubes (CoO x /N-CNTs). The CoO x /N-CNTs composite is derived via pyrolysis of cobalt based zeolitic imidazole framework (ZIF-12) at 950 °C under argon atmosphere. The CoO x /N-CNTs is phosphidized at various temperatures ranging from 320 °C to 400 °C. The optimized temperature to attain the best catalytic activity is 380 °C. The phosphatized material, CoO x -CoP/N-CNTs, shows superior performance towards OER with an overpotential of 250 mV @ 20 mAcm−2 vs 532 mV @ 20 mAcm−2 of un-phosphidized material, CoO x /N-CNTs, which shows significant effect of phosphidization. The maximum current density of 160 mAcm−2 in 1 M KOH solution is achieved. • A novel electrocatalyst, CoO x -CoP/N-CNTs, is fabricated. • The phosphatized material, CoO x -CoP/N-CNTs, shows superior performance towards OER. • During OER activity, an overpotential of 250 mV at 20 mAcm−2 and current density of 160 mAcm−2 is observed. • The electrochemical activity remarkably greater than the un-phosphatized material. [ABSTRACT FROM AUTHOR]

Transition metal oxyhydroxides have been used as promising electrocatalysts for water splitting however, their catalytic activity is restricted due to low surface area and poor conductivity. Herein, we report novel composite FeOOH@ZIF-12/graphene composite as electrocatalyst for water oxidation, whereby ZIF-12 provide extra surface for the FeOOH dispersion whilst graphene act as excellent electron mediator. The composite shows a low overpotential value of 291 mV to attain a current density of 10 mA cm−2 and a low Tafel slope value of 78 mV dec−1. The catalyst offers a maximum current density of 101 mA cm−2, while it gives a turnover frequency (TOF) value of 0.031 s−1 at an overpotential of 291 mV only. The excellent activity and remarkable stability of composite is attributed to highly conductive and porous support. [Display omitted] • FeOOH nanoparticles are incorporated in ZIF-12/graphene matrix. • The synthesized composite is utilized as electrocatalyst for water oxidation. • The composite shows a low overpotential value of 291 mV @ 10 mA cm−2. • The catalyst offers a maximum current density of 101 mA cm−2 with a TOF value of 0.031 s−1. [ABSTRACT FROM AUTHOR]

An efficient electrochemical urea oxidation reaction (UOR) could be used in energy production technology. Metallic nickel nano-particles (Ni NPs) are incorporated in cobalt hydroxide layered material to form Ni/Co(OH) 2. The synthesized material is utilized as an electrocatalyst in UOR. It has been revealed that the incorporation of Ni NPs into cobalt hydroxide significantly enhances their electrocatalytic activity toward UOR. Ni/Co(OH) 2 catalyzes UOR at a very low anodic potential of 1.15 V vs RHE with a peak current density of 14.2 mAcm−2 and Tafel slope of 75 mVdec−1. The current work is a step ahead towards use of transition metal hydroxide (TMH) as support in the electrocatalytic oxidation applications especially UOR. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The dearth of an efficient, robust, abundant and cost-effective water oxidation catalyst is debatably the major hurdle for the technological advancement of artificial photosynthesis devices. Herein, a three dimensional (3D) cobalt-based coordination polymer {[Co 3 (pyz)(fa) 3 (dmso) 2 ]·2H 2 O} n , (1) (pyz = pyrazine, fa = fumarate, dmso = dimethyl sulfoxide) has been synthesized and demonstrated to act as an efficient electrocatalyst towards water oxidation at neutral pH. Compound 1 displays a stair-like arrangement parallel to the b -axis, with the cobalt clusters arranged in a zigzag fashion, and contains small, honeycomb-like channels parallel to the c -axis. Compound 1 shows a remarkable activity for water oxidation and attains a current density of 1 mA.cm−2 at low overpotential (η = 257 mV) with a Tafel slope value of 80.5 mV.dec−1. This high performance of 1 in catalysing the water oxidation reaction is attributed to its unique 3-D architecture. The results of electrochemical investigations, including long-term and controlled potential electrolysis, are anticipated to guide the forthcoming advancement in creating efficient, cheap and noble metal (Pt/Ru/Ir) free catalysts for the water oxidation reaction. [ABSTRACT FROM AUTHOR]

Abstract The development of efficient and cost-effective electrocatalysts for oxygen evolution reaction is a priority research area. Metal-organic frameworks (MOFs) have recently captured attention as heterogeneous water oxidation catalysts. In spite of their robustness and stability under specific pH conditions, the relatively low current density achieved is their main drawback. Herein, we explored a cobalt based framework [Co(bpy)(fa)] n (DMF) 0.25 (bpy) 0.25 (1) {bpy = 4,4ʹ-bipyridine, fa = fumarate, DMF = dimethylformamide} as an efficient electrocatalyst for the water oxidation reaction. Compound 1 exhibits excellent activity in a neutral phosphate buffer solution. Chronoamperometric studies show that 1 offers a current density of 10 mA cm−2 at only η = 382 mV. Onset over-potential of 248 mV is observed which holds a Tafel slope value of 84 mV dec−1. The catalyst showed a turnover frequency (TOF) of 2 × 10−3 s−1 for oxygen evolution reaction (OER) at 289 mV. Detailed electrochemical studies, including long-term electrolysis, indicates the potential of compound 1 to be utilized as heterogeneous catalyst toward the oxygen evolution reaction. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Mercaptoacetic acid (MAA) is used to control the size and for surface functionalization of CuO QDs. • Photoresponsive azobenzene ligand, (E)-5-((4-chlorophenyl) diazenyl)–2-hydroxy benzaldehyde (CPDHB) is attached to QDs. • Photoinjected electron is transferred from the CB of CuO QDs to the LUMO of CPDHB. • The photoinduced charge/energy transfer in QDs-CPDHB system may lead to design fluorescent probes and data storage devices. Abstract A series of stable CuO quantum dots (QDs) in aqueous alkaline medium are prepared and protected against rapid oxidation by capping with mercaptoacetic acid (MAA). The MAA not only regulates the size of the CuO QDs but it also acts as pendent group for further functionalization of QDs. A specific concentration of MAA improves the crystallinity and increases the fluorescence lifetime by decreasing the density of surface trap states. The MAA capped CuO QDs are attached to (E)-5-((4-chlorophenyl) diazenyl)-2-hydroxybenzaldehyde (CPDHB) and upon UV irradiation at 300 nm the CPDHB experiences a reversible trans- to cis-isomerization. The absorption band of the cis-isomer of CPDHB overlaps with the fluorescing band of the CuO QDs, as a result the fluorescence of the QDs is strongly quenched. The photoluminescenc (PL) quenching is attributed due to the photoinjected electron transfer from the conduction band (CB) of the CuO QDs to the lowest unoccupied molecular orbital (LUMO) of the cis-isomer of CPDHB. Förster resonance energy transfer (FRET) is also observed but its contribution is minor. The fluorescence quenching of CuO QDs in QDs - CPDHB assembly upon ultra-violet excitation and reversible trans-cis interconversion of CPDHB may potentially suggests to design fluorescent probes for bioimaging and to develop data and energy storage devices. [ABSTRACT FROM AUTHOR]

Abstract Theoretical modeling of the geometries of metal-organic frameworks is quite challenging. In order to compare the geometry obtained through density functional theory (DFT) calculations with the one obtained experimentally, a hydrothermal reaction of the potassium salt of 1,1-cyclopentane diacetic acid (L) with MnCl 2 ·2H 2 O in the presence of 4,4′-bipyridine (bpy) was carried out which formulated a two dimensional metal-organic framework [Mn 2 (L) 2 (bpy) 2 (H 2 O) 2 ] n ∙6H 2 O. Single crystal X-ray diffraction analysis reveals that the compound crystallized in the centrosymmetric monoclinic space group P 2/n. The presence of solvate water molecules of crystallization offer hydrogen bond formation and result the connection of 2-D sheets into 3-D hydrogen bonded metal-organic framework. The manganese atom can have a maximum of sextet spin state (five unpaired electrons). Single point energies were calculated at M05-2X/6-31G (d,p) for different spin states (up to 11 et) of the high energy framework and it was elucidated that the 11et spin stat is the lowest energy spin state. [ABSTRACT FROM AUTHOR]

Rising consumption and cost of fossil fuels invite the researchers to discover the renewable energy sources. Herein, a novel approach to enhance the photocatalytic performances of rutile-TiO 2 has been revealed. To boost the hydrogen generation reactions, Pd/Rb 2 O cocatalysts have been deposited over TiO 2 via chemical reduction. The morphology and optical characteristics of catalysts were demonstrated by XRD, Raman, UV-Vis/DRS, SEM and TEM analysis. Surface properties, particle sizes, and chemical composition were examined via AFM and XPS techniques. The H 2 production activities were monitored by GC-TCD (Shimadzu-2010/Japan). Comparatively, Pd 1.8 /RbO 0.2 @TiO 2 was found most active catalysts that can deliver hydrogen 22.74 mmolg−1h−1. Higher H 2 generation activities were attributed to the presence of Pd and Rb 2 O cocatalysts. Rb 2 O promoted electrons from TiO 2 to Pd active sites by elevation in fermi energy levels to attain the equilibrium during photoreactions. The mechanistic approach for higher electron transportation and better charge separation has been demonstrated and discussed over here. On the basis of results, it can be concluded that the work reported here in is reliable for sustainable energy applications. [Display omitted] [ABSTRACT FROM AUTHOR]

The present research work was aimed to synthesize biologically active Schiff base compound, 2-{(E)-[(3-{[(Z)-(2-hydroxyphenyl)methylidene]amino}-1H-1,2,4-triazol-5-yl)imino]methyl}phenol (L) by condensation reaction of 2-hydroxybenzaldehyde with 3,5-diamino-1,2,4-triazole. In order to evaluate the effect of metal ions on the biological properties, ligand (L) was then coordinated to the metal ions such as Fe(II), Co(II), Cu(II), Ni(II) and Zn(II). Characterization of ligand and its metal complexes was done by physical, spectral and analytical data. The synthesized compounds were screened for antioxidant, enzyme inhibition and antibacterial/antifungal activities. The screening results indicated the ligand to possess bioactivity which significantly enhanced upon chelation/coordination with the metal ions. Computational studies were also carried out on the ligand to check orbital involvement and bonding interactions. The optimized frequency, intensity and geometry of the vibrational bands of ligand (L) were obtained through density functional theory (DFT) using 6–311++G (d.p) basis sets. Molecular stability and bond strength were also studied by carrying out the natural bond orbital analysis (NBO). The calculated HOMO and LUMO energies confirmed the charge transfer in the molecule of ligand. [ABSTRACT FROM AUTHOR]

The isatin-core in compounds offers exciting perspectives in medicinal and pharmacological research. The present study reports the successful development of new isatin-core transition metal based anti-bacterial complexes via conventional refluxing method. The bidentate nature of as-synthesized isatin-core ligand was confirmed using various analytical techniques such as FTIR, 1 H NMR, 13 C NMR, EIMS, and single crystal X-ray diffraction. The computed analysis i.e. IR, UV–Visible, NBO (Natural Bond Orbital) and FMO (Frontier Molecular Orbital) of crystalline isatin-core ligand reflect its dimer nature and predict the conjugative interaction among molecules. Moreover, metal complexes of isatin-core ligand using metallic salts of first transition series i.e. VO(IV), Cr(III), Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) were prepared and further screened against bacterial strains. Octahedral geometry was proposed for all the complexes except vanadium which had square-pyramidal geometry. All the as-prepared metal complexes are found potentially active entities against both of the gram-positive and gram-negative bacterial strains. Additionally, the bacterial screened data revealed that metal complexes have better bactericidal activities compared to their parent ligand. [ABSTRACT FROM AUTHOR]

Herein, we report the pyrolytic conversion of a metal-organic framework (MOF-5) encapsulated activated carbon (AC) composite to carbon nanospheres at controlled carbonization temperature. The synthesized carbon nanospheres obtained at 850 °C have exhibited Brunauer-Emmett-Teller (BET) surface area and pore volume up to 677 m 2 g −1 and 0.412 cm 3 g −1 , respectively. As an electrode material, a high specific capacitance of 193 F g −1 at 2 mV s −1 and 300 F g −1 at 1.5 A g −1 were calculated from electrochemical studies and during cycling test excellent stability was observed with 91.5% capacitance retention over 3000 cycles. The superior electrochemical performance of the carbon nanospheres as compared to the fragmented porous and activated carbon confirmed that soft-template approach of MOF-5 and AC can be used to produce carbon with enhance mechanical strength. The encapsulation of activated carbon by porous metal-organic frameworks to produce carbon nanospheres is a novel research strategy to obtain desired structural morphology for numerous applications. [ABSTRACT FROM AUTHOR]

A solvo-thermal method is employed to synthesize SnO 2 nanorods and the Fourier transformed infrared spectroscopic analysis confirms the formation of Sn O bond. The X-ray diffraction analysis suggests that SnO 2 nanorods exist in tetragonal rutile crystal structure phase. Transmission electron microscopy images show the formation of nanorods with an average diameter ∼10–15 nm and length 35–50 nm. The deconvoluted photoluminescence spectrum suggests the existence of three distinct origins of photoluminescence, which peaks at photon energies of ∼423 nm (2.93 eV), ∼470 nm (2.64 eV) and 480 nm (2.58 eV). The measured photoluminescence kinetics is best described by a tri-exponential decay model suggesting that the photoluminescence occurs from three distinct channels with time constants 1.31 ns, 4.89 ns and 13.24 ns. These studies suggest that SnO 2 nanorods synthesized by solvo-thermal method at mild conditions can be used for luminescent device applications. The long lived emission of SnO 2 nanorods in the visible region make them suitable candidate as an active materials for many opto-electronic devices such as light emitting diodes and solar cells. [ABSTRACT FROM AUTHOR]