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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.

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...

Layered double hydroxides (LDH) are being used as electrocatalysts for oxygen evolution reactions (OERs). However, low current densities limit their practical applications. Herein, we report a facile and economic synthesis of an iron-copper based LDH integrated with a cobalt-based metal-organic framework (ZIF-12) to form LDH-ZIF-12 composite (1) through a co-precipitation method. The as-synthesized composite 1 requires a low overpotential of 337 mV to achieve a catalytic current density of 10 mA cm−2 with a Tafel slope of 89 mV dec−1. Tafel analysis further demonstrates that 1 exhibits a slope of 89 mV dec−1 which is much lower than the slope of 284 mV dec−1 for LDH and 172 mV dec−1 for ZIF-12. The slope value of 1 is also lower than previously reported electrocatalysts, including Ni-Co LDH (113 mV dec−1) and Zn-Co LDH nanosheets (101 mV dec−1), under similar conditions. Controlled potential electrolysis and stability test experiments show the potential application of 1 as a heterogeneous electrocatalyst for water oxidation.

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.

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.

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.

Correction for ‘Mononuclear copper(i) complexes of triphenylphosphine and N,N′-disubstituted thioureas as potential DNA binding chemotherapeutics’ by Syed Ishtiaq Khan et al., New J. Chem., 2021, 45, 8925–8935, DOI: 10.1039/D0NJ06182D.

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.

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.

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.

Ag-Sn/CeO2 catalysts were synthesized by the co-precipitation method with different Ag-Sn wt.% loadings and were tested for the oxidation of CO. The catalysts were characterized by powder X-ray diffractometry (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDS), and selected area electron diffraction (SAED) techniques. UV-Vis measurements were carried out to elucidate the ionic states of the silver particles, and the temperature-programmed reduction (TPR) technique was employed to check the reduction temperature of the catalyst supported on CeO2. There are peaks for silver crystallites in the X-ray diffraction patterns and the presence of SnO was not well evidenced by the XRD technique due to sintering inside the 3D array channels of CeO2 during the calcination process. The Ag-Sn/CeO2 (4%) catalyst was the most efficient and exhibited 100% CO oxidation at 100 ºC due to small particle size and strong electronic interaction with the SnO/CeO2 support.

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.