Electrocatalytic study of NiO-MOF with activated carbon composites for methanol oxidation reaction.

In this work, the methanol oxidation reaction is investigated on Ni based metal organic frameworks (MOF) and its composites with biomass derived activated carbon. NiO-MOF and composites with activated carbon were synthesized using hydrothermal method. SEM, EDX, and XRD, FTIR, TGA techniques were used for characterization of composites. The electrochemical activity of catalysts for oxidation of methanol was tested using cyclic voltammetry (CV) in 1 M KOH and 3 M CH3OH on glassy carbon electrode in three electrode setup. The electrochemical performance shows the effect of activated carbon concentration on methanol oxidation. The electro-oxidation catalyzed by NiO-MOF with activated carbon (40 mg) composite exhibits a peak current density of 182.72 mA/cm2 at 0.89 V potential with a scan rate of 50 mV/s making it a potential catalyst for electrocatalysis of methanol.

Metal-organic framework based electrode materials for lithium-ion batteries: a review.

Metal-organic frameworks (MOFs) with efficient surface and structural properties have risen as a distinctive class of porous materials through the last few decades, which has enabled MOFs to gain attention in a wide range of applications like drug delivery, gas separation and storage, catalysis and sensors. Likewise, they have also emerged as efficient active materials in energy storage devices owing to their remarkable conducting properties. Metal-organic frameworks (MOFs) have garnered great interest in high-energy-density rechargeable batteries and super-capacitors. Herein the study presents their expanding diversity, structures and chemical compositions which can be tuned at the molecular level. It also aims to evaluate their inherently porous framework and how it facilitates electronic and ionic transportation through the charging and discharging cycles of lithium-ion batteries. In this review we have summarized the various synthesis paths to achieve a particular metal-organic framework. This study focuses mainly on the implementation of metal-organic frameworks as efficient anode and cathode materials for lithium-ion batteries (LIBs) with an evaluation of their influence on cyclic stability and discharge capacity. For this purpose, a brief assessment is made of recent developments in metal-organic frameworks as anode or cathode materials for lithium-ion batteries which would provide enlightenment in optimizing the reaction conditions for designing a MOF structure for the battery community and electrochemical energy storage applications.

Binary counter ion effects and dielectric behavior of iodide ion conducting gel-polymer electrolytes for high-efficiency quasi-solid-state solar cells.

A series of highly efficient quasi-solid-state dye-sensitized solar cells (DSCs) is prepared by harnessing the binary cation effect and positive effects of the selected performance enhancers of gel-polymer electrolytes. The new electrolyte is composed of polyacrylonitrile polymer, tetra-hexylammonium iodide (Hex4NI) and KI binary salts as well as 4-tertbutylpyridine and 1-butyl-3-methylimidazolium iodide performance enhancers. The charge transport in the series of electrolytes is thermally activated and, accordingly, the temperature dependence of conductivity follows the VTF behavior. The enhancement of conductivity is observed with an increasing mass fraction of KI and decreasing mass fraction of Hex4NI, while the total mass fraction of salts in the electrolyte is kept unchanged. The highest conductivity of 3.74 mS cm-1 at ambient temperature is shown by the sample containing KI only (without Hex4NI) at all the temperatures. The effects of dielectric polarization of the electrolytes are studied by analyzing the frequency dependence of the real and the imaginary parts of the AC conductivity in detail. Appropriate and reproducible cell construction are assured by efficiencies of above 5% exhibited by all the quasi-solid-state DSCs assembled using double-layered TiO2 photo-electrodes and the new electrolyte series. Besides, highlighting the mixed cation effect, the cells with mixed salts exhibited efficiencies greater than 6%. An impressively high efficiency of 7.36% was shown by the DSC prepared with electrolyte containing 75 wt% KI and 25 wt% Hex4NI. This study reveals that the salt combination of KI and Hex4NI, which has not been reported before, is a suitable binary iodide salt mixture to prepare highly efficient DSCs. The replacement of tetra-hexylammonium ions by K+ ions improves the charge transport in the electrolyte; however, the best solar cell performance is shown by the mixed salt system with 75 wt% KI and 25 wt% Hex4NI, which is not the highest conductivity composition. Therefore, the exhibited high efficiency of 7.36% is evidently due to the binary cation effect.