Search

With the advancement in technology, demand for green energy production is increasing year by year. To meet the increasing demand for green energy, there has been continuous research in a bid to find better materials and efficient ways to generate energy. Transition metals such as Fe, Mo, Ni, etc. based materials have shown great potential to be used as electrocatalysts for water splitting, and the urea oxidation reaction (UOR). In this work, nanostructured nickel-cobalt oxide and nickel-cobalt sulfide were synthesized using a facile hydrothermal method for their applications in water splitting and UOR. It was observed that the properties of nickel-cobalt oxide improved significantly after converting it to nickel-cobalt sulfide. Nickel-cobalt sulfide showed an overpotential of 282 mV while nickel-cobalt oxide displayed an overpotential of 379 mV to generate a current of 10 mA/cm2 , towards oxygen evolution. After introduction of 0.33 M urea, the potential for oxidation of urea for both nickel-cobalt oxide and nickel-cobalt sulfide is decreased to 1.34 V.

With the advancement in technology, the demand for green energy production and storage is increasing year by year. To meet the increasing demand for green energy, there has been continuous research in a bid to find better materials and efficient ways to store energy. Supercapacitors continue to show a promising green energy storage capacity with their modified and improved electrode materials, which show better electrochemical properties. Transition metals such as Fe, Mo, Ni, etc. based materials have shown great potential for electrode materials in supercapacitors, electrocatalysts for water splitting, and urea oxidation reaction (UOR). In this work, nanostructured nickel‑cobalt oxide and nickel‑cobalt sulfide were synthesized using a facile hydrothermal method for their applications in a supercapacitor, water splitting, and urea oxidation reaction. It was observed that the properties of nickel‑cobalt oxide improved significantly after converting it to nickel‑cobalt sulfide. The energy storage capacity of nickel‑cobalt sulfide was significantly enhanced compared to nickel‑cobalt oxide. Additionally, nickel‑cobalt sulfide showed an overpotential of 282 mV, while nickel‑cobalt oxide displayed an overpotential of 379 mV to generate a current density of 10 mA/cm2, towards oxygen evolution reaction. After the introduction of 0.33 M urea, the potential for oxidation of urea for both nickel‑cobalt oxide and nickel‑cobalt sulfide was reduced significantly.

A polymer brush consisting of 70% poly(N-isopropylacrylamide) (PNIPAAM) and 30% polymethacrylic acid (PMAA) was synthesized from gold substrates with a "grafting from" AIBN-type free-radical initiator. Fractionation of two peptides, bradykinin and buccalin, was accomplished in less than 120 s by placing a 30 pM (pH approximately 6.2) droplet onto the polymer brush substrate. The eluant containing the anionic buccalin is pipetted away for MALDI analysis while the cationic bradykinin adsorbed to the swollen anionic brush and was subsequently released by adding a droplet of formic acid to the substrate. This caused the brush to collapse and release the bradykinin, much like squeezing a sponge; these nanosponge substrates exhibited very high loading capacity (>2.0 mg/mL) compared to plasma-polymer-modified MALDI substrates. Ellipsometric measurements showed that complementary peptides adsorb rapidly while those of the same charge do not, and MALDI-MS analysis of the two fractions showed separation of both peptides. The adsorption of bradykinin was monitored over time, and 85% of the peptide had been adsorbed to the nanosponge in 1 min from a 0.5 mg/mL aqueous solution.

Thin film depositions of rf plasma polymerized N-isopropylacrylamide (ppNIPAM) show a phase transition temperature below which the polymer surface is hydrophilic, and protein nonadsorptive, and above which the polymer surface is hydrophobic, and protein-retentive. Results presented here demonstrate that this thermoresponsive plasma polymer can be coated on the surface of a MALDI probe and subsequently used for on-probe biomolecule cleanup. Specifically, a contaminated biomolecule can be applied to the ppNIPAM coated MALDI probe surface at a temperature above the phase transition temperature, washed using solvent also held above the phase transition temperature, and then analyzed by reducing the probe temperature to room temperature before adding the MALDI matrix. With the use of this approach, it is demonstrated that cytochrome c contaminated with 0.3% SDS, which yields only a very weak MALDI ion signal as directly deposited, can be purified on-probe using the thermoresponsive plasma polymer to improve significantly the ion signal. It is further shown that the decontamination of whole cell protein extracts from cyanobacteria is augmented through the use of the ppNIPAM coated MALDI probe.