@article { ISI:000311056800010, title = {3D Hexaporous carbon assembled from single-layer graphene as high performance supercapacitor}, journal = {Chemsuschem}, volume = {5}, number = {11}, year = {2012}, month = {OCT}, pages = {2159-2164}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, keywords = {Electrochemistry, Energy storage, graphene, porous materials, Supercapacitors}, issn = {1864-5631}, doi = {10.1002/cssc.201200421}, author = {Yadav, Prasad and Banerjee, Abhik and Unni, Sreekuttan and Jog, Jyoti Prakash and Kurungot, Sreekumar and Ogale, Satishchandra} } @article { ISI:000313263300022, title = {Porous-organic-framework-templated nitrogen-rich porous carbon as a more proficient electrocatalyst than Pt/C for the electrochemical reduction of oxygen}, journal = {Chemistry-A European Journal}, volume = {19}, number = {3}, year = {2013}, month = {JAN}, pages = {974-980}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Porous nitrogen-rich carbon (POF-C-1000) that was synthesized by using a porous organic framework (POF) as a self-sacrificing host template in a nanocasting process possessed a high degree of graphitization in an ordered structural arrangement with large domains and well-ordered arrays of carbon sheets. POF-C-1000 exhibits favorable electrocatalytic activity for the oxygen-reduction reaction (ORR) with a clear positive shift of about 40 mV in the onset potential compared to that of a traditional, commercially available Pt/C catalyst. In addition, irrespective of its moderate surface area (785 m2?g-1), POF-C-1000 showed a reasonable H2 adsorption of 1.6 wt?\% (77 K) and a CO2 uptake of 3.5 mmol?g-1 (273 K).

}, keywords = {Adsorption, Electrochemistry, fuel cells, oxygen-reduction reaction, porous organic frameworks}, issn = {0947-6539}, doi = {10.1002/chem.201202940}, author = {Pachfule, Pradip and Dhavale, Vishal M. and Kandambeth, Sharath and Kurungot, Sreekumar and Banerjee, Rahul} } @article { ISI:000325849000034, title = {Zeolitic imidazolate framework (ZIF)-derived, hollow-core, nitrogen-doped carbon nanostructures for oxygen-reduction reactions in PEFCs}, journal = {Chemistry-A European Journal}, volume = {19}, number = {28}, year = {2013}, month = {JUL}, pages = {9335-9342}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The facile synthesis of a porous carbon material that is doped with iron-coordinated nitrogen active sites (FeNC-70) is demonstrated by following an inexpensive synthetic pathway with a zeolitic imidazolate framework (ZIF-70) as a template. To emphasize the possibility of tuning the porosity and surface area of the resulting carbon materials based on the structure of the parent ZIF, two other ZIFs, that is, ZIF-68 and ZIF-69, are also synthesized. The resulting active carbon material that is derived from ZIF-70, that is, FeNC-70, exhibits the highest BET surface area of 262m2g-1 compared to the active carbon materials that are derived from ZIF-68 and ZIF-69. The HR-TEM images of FeNC-70 show that the carbon particles have a bimodal structure that is composed of a spherical macroscopic pore (about 200nm) and a mesoporous shell. X-ray photoelectron spectroscopy (XPS) reveals the presence of Fe-N-C moieties, which are the primary active sites for the oxygen-reduction reaction (ORR). Quantitative estimation by using EDAX analysis reveals a nitrogen content of 14.5wt.\%, along with trace amounts of iron (0.1wt.\%), in the active FeNC-70 catalyst. This active porous carbon material, which is enriched with Fe-N-C moieties, reduces the oxygen molecule with an onset potential at 0.80V versus NHE through a pathway that involves 3.3-3.8e- under acidic conditions, which is much closer to the favored 4e- pathway for the ORR. The onset potential of FeNC-70 is significantly higher than those of its counterparts (FeNC-68 and FeNC-69) and of other reported systems. The FeNC-based systems also exhibit much-higher tolerance towards MeOH oxidation and electrochemical stability during an accelerated durability test (ADT). Electrochemical analysis and structural characterizations predict that the active sites for the ORR are most likely to be the insitu generated NFeN2+2/C moieties, which are distributed along the carbon framework.

}, keywords = {Doping, Electrochemistry, metal-organic frameworks, Nanostructures, oxygen-reduction reaction}, issn = {0947-6539}, doi = {10.1002/chem.201300145}, author = {Palaniselvam, Thangavelu and Biswal, Bishnu P. and Banerjee, Rahul and Kurungot, Sreekumar} } @article {44552, title = {Porous reduced graphene oxide modified electrodes for the analysis of protein aggregation. Part 2: Application to the analysis of calcitonin containing pharmaceutical formulation}, journal = {Electrochimica Acta}, volume = {266}, year = {2018}, month = {MAR }, pages = {364-372}, abstract = {

In part 1 (A. Vasilescu et al., Porous reduced graphene oxide modified electrodes for the analysis of protein aggregation. Part 1: Lysozyme aggregation at pH 2 and 7.4 Electrochem. Acta, 254 (2017) 375 -383) we proposed porous reduced graphene oxide coated glassy carbon electrode (GC/prGO) in combination with differential pulse voltammetry as a new analytical tool for aggregation studies of proteins. Lysozyme was used as a model to follow its aggregation by electrochemical means at pH 2 and pH 7.4, leading to the formation of amyloid and amorphous aggregates, respectively. Part 2 of this work widens the scope of this approach by investigating a biopharmaceutical product, as the aggregation of peptide based drugs affects their therapeutic activity and can induce allergic reactions in patients. The salmon polypeptide calcitonin (sCT) was chosen as an example of a bioactive peptide with limited pharmaceutical potential due to a tendency to form cytotoxic aggregates and amyloid fibrils. For practical applications, screen printed electrodes (SPE) and flexible electrodes (FE) modified with polydiallyldimethylammonium (PDDA) and prGO by using the layer-by-layer deposition technique have been developed for the detection of sCT. The results indicate that these electrodes can differentiate between formation of amyloid aggregates of calcitonin (2 mg mL(-1)) in citrate buffer to no aggregation in acetate buffer. It was further demonstrated that these electrodes are able to analyze a pharmaceutical drug product of low potency, Miacalcic (8.3 mu g mL(-1)), where no aggregation was observed. (C) 2018 Elsevier Ltd. All rights reserved.

}, keywords = {Calcitonin, Disposable electrodes, Electrochemistry, Porous reduced graphene oxide, Protein aggregation}, issn = {0013-4686}, doi = {10.1016/j.electacta.2018.02.038}, author = {Vasilescu, Alina and Ye, Ran and Boulahneche, Samia and Lamraoui, Sabrina and Jijie, Roxana and Medjram, Mohamed Salah and Gaspar, Szilveszter and Singh, Santosh K. and Kurungot, Sreekumar and Melinte, Sorin and Boukherroub, Rabah and Szunerits, Sabine} } @article {46430, title = {Glycine-induced electrodeposition of nanostructured cobalt hydroxide: a bifunctional catalyst for overall water splitting}, journal = {ChemSusChem}, year = {2019}, month = {NOV}, type = {Article; Early Access}, abstract = {

Herein, an interconnected alpha-Co(OH)(2) structure with a network-like architecture was used as a bifunctional electrocatalyst for the overall water splitting reaction in alkaline medium. The complexing ability of glycine with a transition metal was exploited to form [Co(gly)(3)](-) dispersion at pH 10, which was used for the electrodeposition. High-resolution TEM, UV/Vis-diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy were used to confirm that the as-synthesized materials had an alpha-Co(OH)(2) phase. The electrocatalytic oxygen and hydrogen evolution activity of the glycine-coordinated alpha-Co(OH)(2) was found to be approximately 320 and 145 mV, respectively, at 10 mA cm(-2). The material required approximately 1.60 V (vs. reversible hydrogen electrode; RHE) to achieve the benchmark of 10 mA cm(-2) for overall water splitting with a mass activity of approximately 63.7 A g(-1) at 1.60 V (vs. RHE). The chronoamperometric response was measured to evidence the stability of the material for overall water splitting for up to 24 h. Characterization of the catalyst after the oxygen and hydrogen evolution reactions was performed by XPS and showed the presence of a Co-II/Co-III oxidation state.

}, keywords = {cobalt, Electrochemistry, heterogeneous catalysis, Hydrogen, water splitting}, issn = {1864-5631}, doi = {10.1002/cssc.201902323}, author = {Shilpa, Nagaraju and Nadeema, Ayasha and Kurungot, Sreekumar} } @article {48232, title = {Single-step synthesis of exfoliated Ti3C2Tx MXene through NaBF4/HCl etching as electrode material for asymmetric supercapacitor}, journal = {ChemistrySelect}, volume = {7}, year = {2022}, month = {MAY}, pages = {e202201166}, type = {Article}, abstract = {

Two-dimensional Ti3C2Tx MXene, derived from the parent Ti3AlC2 phase, is considered a promising electrode material for electrochemical energy storage applications. Ti3C2Tx MXene synthesis methods often employ concentrated hydrofluoric acid (HF), which is harsh, corrosive, and hazardous to the environment. Herein, we report the preparation of Ti3C2Tx MXene following a new synthetic route under a mild reaction condition comprising an aqueous solution of NaBF4 and HCl. This etching environment at a moderate temperature of 130 degrees C effectively removes the Al layer of the Ti3AlC2 precursor, assisted by the in situ formed HF in the reaction medium. Electron microscopy images of the as-prepared Ti3C2Tx (MX-130) reveal a partially exfoliated nanosheet-like morphology. The material displays a specific capacitance of 262 F g(-1) (three-electrode assembly, 1 A g(-1), -0.85 to -0.25 V vs. Hg/Hg2SO4) in 1 M H2SO4 electrolyte. The achieved specific capacitance is superior to that of Ti3C2Tx prepared via the common HF-treatment (25 F g(-1)). Additionally, the potential application of the optimized MXene as a negative electrode material is demonstrated in a quasi-solid-state RuO2|MX-130 asymmetric supercapacitor device.

}, keywords = {asymmetric supercapacitor, Electrochemistry, Fluoride salt etchant, Layered electrode materials, Transition metal carbides}, issn = {2365-6549}, doi = {10.1002/slct.202201166}, author = {Ghosh, Meena and Szunerits, Sabine and Cao, Ning and Kurungot, Sreekumar and Boukherroub, Rabah} }