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Porous carbon (PC) is obtained by carbonizing a zinc-coordination polymer (MOF-5) at 950 °C and PtM (M = Fe, Co, Ni, Cu, Zn) nanoparticles (NPs), which are deposited on PC using the polyol method. Structural and morphological characterizations of the synthesized materials are carried out by powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM), and the porosity was determined using a N2 adsorption/desorption technique. The results revealed that PtM NPs are alloyed in the fcc phase and are well dispersed on the surface of PC. The electrochemical results show that PtM/PC 950 catalysts have higher methanol oxidation reaction (MOR) performances than commercial Pt/C (20%) catalysts. After 3000 s of chronoamperometry (CA) test, the MOR performances decreased in the order of Pt1Cu1/PC 950 > Pt1Ni1/PC 950 > Pt1Fe1/PC 950 > Pt1Zn1/PC 950 > Pt1Co1/PC 950. The high MOR activities of the synthesized catalysts are attributed to the effect of M on methanol dissociative chemisorption and improved tolerance of Pt against CO poisoning. The high specific surface area and porosity of the carbon support have an additional effect in boosting the MOR activities. Screening of the first row transition metals (d5+n , n = 1, 2, 3, 4, 5) alloyed with Pt binary catalysts for MOR shows that Pt with d8 (Ni) and d9 (Cu) transition metals, in equivalent atomic ratios, are good anode catalysts for alcohol fuel cells.

In this work, nine new mixed-ligand complexes with the general formula [CuBr(TPP)2Tu1–9] were synthesized. The copper(I) complexes of triphenylphosphine (TPP) and different N,N′-disubstituted thioureas (Tu) were characterized via spectroscopic techniques including Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (1H, 13C, and 31P NMR), and single-crystal X-ray diffraction (SC-XRD). The complexes were synthesized via the direct reaction of bromo(tris(triphenylphosphine)copper(I)) [BrCu(PPh3)3] precursor and thiourea ligand solution under ambient conditions. Complexes 1, 2 and 3 crystallized in a triclinic system with the P space group. Each complex is mononuclear, and the copper atom is tetrahedrally attached to two TPP groups through the phosphorous atom, one thiourea molecule through the sulfur atom and one bromine atom. The synthesized compounds were docked with a DNA macromolecule to predict their binding site and it was found that all molecules showed favorable binding to the DNA minor grooves. The DNA interaction studies of the representative complexes demonstrated their efficient DNA binding affinities. Based on the docking and DNA interaction results, complex 7 was found to be the best binder with a docking affinity of 382.2 kJ mol−1 and binding constant of 3.96 × 104 M−1. This compound tends to interact with the minor groove through the bromine atom positioning the side triphenylphosphine rings along the X-axis of the groove while keeping the 1-(2-chlorobenzyl)-3-(3-(trifluoromethyl)phenyl)thiourea ring on the outside.

Ionic liquids (ILs) composed of tetra(n-butyl)phosphonium [P4444]+ and tetra(n-butyl)ammonium [N4444]+ cations paired with 2-furoate [FuA]−, tetrahydo-2-furoate [HFuA]−, and thiophene-2-carboxylate [TpA]− anions are prepared to investigate the effects of electron delocalization in anion and the mutual interactions between cations and anions on their physical and electrochemical properties. The [P4444]+ cations-based ILs are found to be liquids, while the [N4444]+ cations-based ILs are semi-solids at room temperature. Thermogravimetric analysis revealed higher decomposition temperatures and differential scanning calorimetry analysis showed lower glass transition temperatures for phosphonium-based ILs than the ammonium-based counterparts. The ILs are arranged in the decreasing order of their ionic conductivities as [P4444][HFuA] (0.069 mS cm–1) > [P4444][FuA] (0.032 mS cm–1) > [P4444][TpA] (0.028 mS cm–1) at 20 °C. The oxidative limit of the ILs followed the sequence of [FuA]−> [TpA]−> [HFuA]−, as measured by linear sweep voltammetry. This order can be attributed to the electrons’ delocalization in [FuA]− and in [TpA]− aromatic anions, which has enhanced the oxidative limit potentials and the overall electrochemical stabilities.

Here, we investigate the physicochemical and electrochemical properties of fluorine-free ionic liquid (IL)-based electrolytes with two different cations, tetrabutylphosphonium, (P-4,4,4,(4))(+), and tetrabutylammonium, (N-4,N-4,N-4,N-4)(+), coupled to a new anion, 2-[2-(2-methoxyethoxy)ethoxylacetate anion (MEEA), for both neat and (P-4,P-4,P-4,P-4) (MEEA)(-), also doped with 10-40 mol % of Li(MEEA). We find relatively weaker cation-anion interactions in (P-4,P-4,P-4,P-4)(MEEA) than in (N-4,N-4,N-4,N-4)(MEEA), and for both ILs, the structural flexibility of the oligoether functionality in the anion results in low glass transition temperatures, also for the electrolytes made. The pulsed field gradient nuclear magnetic resonance (PFG NMR) data suggest faster diffusion of the (MEEA)(-) anion than (P-4,P-4,P-4,P-4)(+) cation in the neat IL, but the addition of a Li salt results in slightly lower mobility of the former than the latter and lower ionic conductivity. This agrees with the combined Li-7 NMR and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy data, which unambiguously reveal preferential interactions between the lithium cations and the carboxylate groups of the IL anions, which also increased as a function of the lithium salt concentration. In total, these systems provide a stepping stone for further design of fluorine-free and low glass transition temperature IL-based electrolytes and also stress how crucial it is to control the strength of ion-ion interactions.

We synthesized tetra(n-butyl)phosphonium furoate [P4444][FuA] ionic liquid (IL) by the reaction of tetra(n-butyl)phosphonium hydroxide and 2-furoic acid using water as a solvent at room temperature...

Here we focus on the thermal and variable temperature electrochemical stabilities of two ionic liquids (ILs) having a common tributyloctyl phosphonium cation [P4,4,4,8]+ and two different orthoborate anions: bis(mandelato)borate [BMB]&minus, and bis(salicylato)borate [BScB]&minus, The thermo-gravimetric analysis data suggest that [P4,4,4,8][BScB] is thermally more stable than [P4,4,4,8][BMB] in both nitrogen atmosphere and air, while the impedance spectroscopy reveals that [P4,4,4,8][BScB] has higher ionic conductivity than [P4,4,4,8][BMB] over the whole studied temperature range. In contrast, the electrochemical studies confirm that [P4,4,4,8][BMB] is more stable and exhibits a wider electrochemical stability window (ESW) on a glassy carbon electrode surface as compared to [P4,4,4,8][BScB]. A continuous decrease in the ESWs of both ILs is observed as a function of operation temperature.

The translational as well as reorientational mobilities of fluorine-free electrolytes prepared by mixing lithium furan-2-carboxylate Li(FuA) salt with tetra(n-butyl)phosphonium furan-2-carboxylate (P4444)(FuA) ionic liquid are thoroughly investigated. The diffusivity of ions and T1 relaxation of protons belonging to various chemical groups of (P4444)+ and (FuA)− ions and the Li+ ion present in these electrolytes are measured as a function of lithium salt concentration and temperature. The temperature dependence of correlation time for reorientational mobility of various chemical groups of (P4444)+ and (FuA)− ions and the Li+ ion are estimated and used in calculations temperature dependence of the corresponding reorientational rates. It is shown that an increase in the concentration of lithium salt leads to a decrease in both the diffusion coefficients and the reorientation rates for all the chemical groups in concerted way. Activation energy of the reorientational rates for different chemical groups of the organic ions and the Li+ are discussed in details.

Efficient and noble metal-free electrocatalyst could enhance conceivably fuel cell's affordable commercialization. In this esteem, we developed CoO embedded N-doped CNTs from zeolitic imidazolate framework (ZIF-12) by single step inert atmosphere calcination, to be used as oxygen reduction reaction (ORR) electrocatalyst. In the electrochemical studies performed, the CoO/N-CNTs has demonstrated an onset potential of 0.83 V vs. RHE, very close to the commercial Pt catalyst value, electron transfer number of 3.5 which approaches the theoretical value of 4 and current density of 3.35 mA cm − 2 at 2500 rmp. The excellent activity of the electrocatalyst is to be attributed to its waved-tubular structure casing CoO particles and to its high surface area as it was proved by TEM and gas adsorption analysis.

Boosting the durability of Pt nanoparticles by controlling the composition and morphology is extremely important for fuel cells commercialization. We deposit the Pt-Cu alloy nanoparticles over high surface area carbon in different metallic molar ratios and optimize the conditions to achieve desired material. The novel bimetallic electro-catalyst {Pt-Cu/PC-950 (15:15%)} offers exceptional electrocatalytic activity when tested for both oxygen reduction reaction and methanol oxidation reactions. A high mass activity of 0.043 mA/μgPt (based on Pt mass) is recorded for ORR. An outstanding longevity of this electro-catalyst is noticed when compared to 20 wt % Pt loaded either on PC-950 or commercial carbon. The high surface area carbon support offers enhanced activity and prevents the nanoparticles from agglomeration, migration, and dissolution as evident by TEM analysis.

The development of highly competent electrocatalysts for the sluggish oxygen reduction reaction (ORR) at cathodes of proton-exchange membrane fuel cells (PEMFCs) is extremely important for their long-term operation and wide applications. Herein, we present highly efficient ORR electrocatalysts based on Pt/Ni bimetallic nanoparticles dispersed on highly porous carbon obtained via pyrolysis of a metal-organic framework MOF-5. In comparison to the commercial Pt/C (20%), the electrocatalyst Pt-Ni/PC 950 (15:15%) in this study exhibits a pronounced positive shift of 90 mV in Eonset. In addition, it also demonstrates excellent long-term stability and durability during the 500-cycle continue-oxygen-supply (COS) accelerating durability tests (ADTs). The significantly improved activity and stability of Pt-Ni/PC 950 (15:15%) can be attributed to the Pt electron interaction with Ni and carbon support as has been proved in X-ray and microscopic analysis.

A series of Fe/Fe3C-containing N-doped porous carbon materials (Fe/NC) were prepared by pyrolyzing composites that contained a metal–organic framework (MIL-88c-Fe) with dicyandiamide. The Fe/NC obtained at 800 °C (Fe/NC800) showed comparable onset potential and kinetics to that of the commercial Pt/C catalyst in catalyzing the oxygen reduction reaction (ORR). Further measurements suggested that it has better durability and much higher methanol tolerance than Pt/C. Acid leaching was performed to reveal the critical role of Fe-containing sites in ORR catalysis.

Graphitic carbon material encasing chromium oxide nanoribbons [Cr 2 O 3 –C composite] is obtained by carbonizing a mixture of furfuryl alcohol and Cr-BDC MOF [BDC: benzene dicarboxylic acid; Cr 3 F(H 2 O) 2 O[(O 2 C)C 6 H 4 –(CO 2 )] 3 ·nH 2 O] at 900 °C under inert atmosphere. The Ni–Pd nanoparticles synthesized by NaBH 4 reduction method are loaded on the Cr 2 O 3 –C support via sonication. Morphological, structural, and chemical analysis of the designed chromia based carbon support and synthesized nanoparticles is carried out with PXRD, EDX, SEM, HR-TEM and BET surface area. The gas adsorption analyses reveal that BET surface area of Cr 2 O 3 –C support decreases from 438 m 2 g −1 to 171 m 2 g −1 by the incorporation Ni–Pd nanoparticles. The electro-oxidation reaction of methanol is carried out over the designed electrocatalysts in acidic media. The Ni–Pd nanoparticles supported on Cr 2 O 3 –C have presented a significant increase in catalytic activity for methanol oxidation and tolerance in comparison to the nanoparticles supported on activated carbon and glassy carbon electrode.

In this article, we described a simple method of PdCu nanoparticles (NPs) synthesis in different morphologies at 120 °C using polyvinylpyrrolidone (PVP) capping agent and ethylene glycol (EG) solvent. Form instrumental characterization it is find out that PdCu NPs are prepared in different morphologies by varying the Pd:Cu weight percent (wt.%) ratios. Nanospheres (NS) are obtained in the absence of Cu, sphere-like NPs having Pd3Cu1 composition are obtained at 3:1 wt.% ratio, cubic NPs having Pd1Cu1 composition are obtained at 1:1 wt.% ratio and cube-like NPs having Pd1Cu3 composition are obtained at 1:3 wt.% ratio. The metals wt.% ratio not only controlled the morphology, but also affected the catalytic activity toward methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR) in alkaline media. The PdCu catalyst, in 1:1 wt.% ratio, have demonstrated high specific and mass activities toward MOR (18.07 mA cm−2 and 11.15 A mgPd−1) and EOR (10.24 mA cm−2 and 6.32 A mgPd−1) in alkaline media. Excellent catalytic activity and long-term stability of Pd1Cu1 toward both MOR and EOR is attributed to its stable cubic morphology, composition and synergetic effect, high electrochemical active surface area (ECSA) and PdO reduction at more negative potential. In comparison to the literature, the cubic-PdCu is one of the best electorcatalyst toward MOR and EOR. The cubic-PdCu NPs as anode have potential application in direct alcohol fuel cells owing to their excellent electrochemical performance, stability and cost effectiveness.

Cobalt oxide embedded nitrogen-doped carbon nanotubes (CoO/N-CNT) are synthesized by the direct carbonization of a cobalt–benzimidazole framework (ZIF-12) at 950 °C under an inert atmosphere. X-ray photoelectron spectroscopy indicates the conducting graphitic networks of the CNT contain edge and aromatic substituted pyridinic-nitrogen. Microscopy reveals the extensive formation of multi-walled CNT encasing CoO nanoparticles. This trapping of CoO nanoparticles within the nitrogen doped CNT network is discussed as the key basis of improving the material's contact resistance and conductivity to achieve high power outputs, together with the high specific surface area (365 m2 g−1) and structural robustness of the novel composite material. The material shows an excellent lithium charge/discharge and storage, retaining ∼95% capacity after 50 cycles and a reversible capacity of ∼1100 mA h g−1 at a current density of 0.1 A g−1, which far exceeds the performance of conventional lithium ion battery anode materials under similar conditions.

Microporous carbon materials are obtained by carbonizing a mixture of Zn–BTC MOF [Zn 2 (BTC) 3 {BTC; 1, 3, 5-benzenetricarboxylic acid}] and polyfurfuryl alcohol (Zn–BTC MOF/PFA) at different carbonization temperatures. The obtained samples are characterized by PXRD, XPS, SEM, TEM, gas sorption and Raman spectroscopic analysis. The maximum BET surface area of 1455 m 2 g −1 is recorded for the porous carbon obtained at 950 °C. The incorporation of furfuryl alcohol in the 3D channels of Zn–BTC MOF results in creation of three distinct pore-regions; ultra-micropores (0.45–0.9 nm), micropores (0.9–2 nm) and mesopores (2–3.7 nm) exist with total pore volume of 2.03 cm 3 g −1 . The MPC-950 exhibits an enhanced specific capacitance of 471 F g −1 at 2 mV s −1 and 375 F g −1 at 0.75 A g −1 and retains ca. 96% of its initial capacitance over 3000 cycles.

Novel graphitic material containing chromium oxide (Cr2O3) nanoribbons is obtained by carbonizing a mixture of polyfurfuryl alcohol and MIL–101(Cr) at 900 °C. Morphological, structural, and chemical analysis of the product is carried out with HR–TEM, SEM, XPS, XRD, and BET surface area. The maximum BET surface area recorded for the nanocomposite is 438 m2 g−1. The nanocomposite exhibits a specific capacitance as high as 300 F g−1 at 2 mV s−1 and 291 F g−1 at 0.25 A g−1, and presents 95.5% long–term cycling stability over 3000 cycles. The pseudo-capacitive role of Cr2O3 nanoribbons is found to be important towards total capacitance of nanocomposite material.

Twelve new complexes, of the general formula CuCl(TPP)2Tu1-12 (Tu = thiourea), were synthesized by the reaction of CuCl(TPP)3 (TPP = triphenylphosphine) and various N,N′-disubstituted thioureas. The structures of the synthesized complexes were characterized by different techniques such as Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy (1H, 13C, 31P and 19F) and the representative complexes (1, 2 and 12) were analyzed via single crystal X-ray diffraction. The single crystal X-ray analysis revealed that copper(I) is coordinated with chlorine, two TPP and the thiourea ligands through the sulfur atom in a mononuclear distorted tetrahedral mode. The compounds were tested for antibacterial, antifungal, cytotoxicity, antileishmanial and antioxidant activities. The results showed that the synthesized complexes are significantly more active than the free ligands and the commercial reference compounds. The high biological activities of the complexes versus free ligands can be attributed to the copper(I) chloride complexation with thiourea ligands. The synthesized complexes were also evaluated, both experimentally and theoretically, for DNA binding studies. The UV-visible spectroscopic and molecular docking studies demonstrated that the complexes are conjugating with DNA through a groove binding mode.

A simple and facile method is adopted for the synthesis of pure and catalyst free carbon material for supercapacitor applications. In a co-crystal synthesis, the precursors (isophthalic acid and a base, 4,4′-bipyridine) are arranged in regular pattern, followed by carbonization at 600 °C under an inert atmosphere to produce pure carbon material, CIN-600. The obtained sample is characterized by many techniques, such as powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and gas adsorption analysis. The gas adsorption and microscopic analysis demonstrated the high porosity of the carbon sample and its irregular geometry. Owing to the excellent porosity and electrical conducting properties, CIN-600 showed enhanced capacitive performance when used as an electrode material in electric double layer capacitors. The specific capacitance of the sample was ca.181.3 F g−1 at 2 mV s−1 and maintained 91.3% of its initial capacitance in a long-term cycling test.

Electrochemical energy conversion and storage devices such as fuel cells and metal-air batteries have been extensively studied in recent decades for their excellent conversion efficiency, high energy capacity, and low environmental impact. However, sluggish kinetics of the oxygen-related reactions at air cathodes, i.e., oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), are still worth improving. Noble metals such as platinum (Pt), iridium (Ir), ruthenium (Ru) and their oxides are considered as the benchmark ORR and OER electrocatalysts, but they are expensive and prone to be poisoned due to the fuel crossover effect, and may suffer from agglomeration and leaching after long-term usage. To mitigate these limits, it is highly desirable to design alternative ORR/OER electrocatalysts with prominent performance. Metal-organic frameworks (MOFs) are a class of porous crystalline materials consisting metal ions/clusters coordinated by organic ligands. Their crystalline structure, tunable pore size and high surface area afford them wide opportunities as catalytic materials. This Review covers MOF-derived ORR/OER catalysts in electrochemical energy conversion, with a focus on the different strategies of material design and preparation, such as composition control and nanostructure fabrication, to improve the activity and durability of MOF-derived electrocatalysts.

The article describes the conversion of MOF-199 to Cu–Cu 2 O–CuO/C 700 ( 1 ) and Cu–Cu 2 O–CuO/C 800 ( 2 ) nanostructures by simple pyrolysis at 700 and 800 °C under inert atmosphere. The X-ray photoelectron spectroscopy analysis reveals that the nanostructures Cu–Cu 2 O–CuO/C consist of graphitic carbon functionalized with carboxylic, carbonyl and hydroxyl functional groups with copper/copper oxide particles on surfaces. The electrochemical properties of 1 and 2 are evaluated as electrode material for supercapacitors using cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results for the capacitive performance from cyclic voltammetry and galvanostatic charge/discharge reveal that both the samples have gravimetric capacitance greater than 750 F g −1 at a scan rate of 2 mV s −1 and current density of 2 mA cm −2 . The samples retain about 43% of their initial capacitance even at high scan rate of 75 mV s −1 . The cycling performance of the nanostructures illustrate that there is 5.5% capacitance loss after 3000 cycles. The sample 1 and 2 are washed with 1 mol L −1 HCl solution to obtain copper oxide free materials Cu/C 700 ( 3 ) and Cu/C 800 ( 4 ). Samples 3 and 4 are tested as electrocatalysts for glucose sensing and the cyclic voltammetry measurement shows enhanced current densities compared to the literature values.

Ceria (CeO2) and zirconia (ZrO2) supported Pt and Co3O4-based nanocatalysts were synthesized and characterized by different instrumental techniques. The catalysts redox properties and active surface areas were evaluated using temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO) and H2-pulse chemisorption, respectively. The catalysts were tested for the thermal oxidation of carbon monoxide (CO), reduction of nitrous oxide (N2O) and conversion of N2O/CO mixture (1:1 vol%) . In catalytic tests, Pt–Co3O4/CeO2 (10:10%) oxidized CO up to 100% at 25 °C and Co3O4/CeO2 (20%) reduced N2O up to 90% at 320 °C. Moreover, Pt–Co3O4/CeO2 (10:10%) converted N2O/CO mixture to N2/CO2 up to 90% at about 210 °C. The low-temperature catalytic activity of Pt–Co3O4/CeO2 (10:10%) for CO oxidation and N2O/CO mixture redox conversion were attributed to uniform particle size, metals and support proper combination and electron interaction.

In this article we have presented the synthesis, chemical characterisation (by NMR and FTIR spectroscopy, atomic absorption spectrophotometry, elemental analysis, and single crystal X-ray diffraction), electrochemistry, and DNA binding studies (with cyclic voltammetry, viscometry, and UV-vis spectroscopy) of six new ferrocene incorporated selenoureas. All the six compounds interact electrostatically with DNA which was evident by a negative shift in the cyclic voltammetry peak potential of the drug–DNA adduct relative to the free drug. The drug–DNA binding constant was calculated by a decrease in peak current after the addition of DNA to the free drug. We have also reported binding site sizes and diffusion coefficients of the synthesised compounds.