Electrocatalysis最新文献

In this study, the synthesis and properties of a selective electrochemical sensor for the determination of osimertinib (OSIM) as an anticancer drug using the bimetal-organic framework (MOF) were reported. Herein, MOF based on nickel/manganese (Ni/Mn-MOFs) was successfully created using the solvothermal method and applied for the amperometric detection of OSIM. Then, Ni/Mn-MOF was analyzed through a field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD). The electrocatalytic performance of the introduced MOF is used in the electrochemical determination of the OSIM drug. The synthesized MOF leads to a noticeable improvement in the electrochemical performance which is ascribed to the many electrocatalytic sites, wide electrode–electrolyte contact area, and excellent electrical conductivity. This is the first study on the use of Ni/Mn-MOF to detect of OSIM. The Ni/Mn-MOF modified glassy carbon electrode (Ni/Mn-MOF/GCE) exhibited a good linear range from 0.5 to 800 μM and 800 to 1800 μM with a low detection limit (LOD) as 0.16 μM. In addition, the proposed sensor possessed good anti-interference properties, repeatability, stability, and reproducibility. The mentioned substrate to detect OSIM in the samples of blood serum was successfully applied. This research displays that MOFs are reliable materials for designing effective electrochemical sensors to detect drugs easily. The existing research results provide insights into the promotion and development of the bimetal-organic framework in the field of electrochemical applications and promising for usage in other electrochemical studies.

This study revisits the impacts of the presence of OH⁻ and Cl⁻ anions and/or different forms of Pt precursors during polyol synthesis of carbon-supported electrocatalysts. Efficiency of the synthesis process in terms of the %conversion of a Pt complex to Pt metal has been quantified. It is observed that Pt precursors based on [PtCl₆]²⁻ are reduced easily compared to those based on [Pt(OH)₆]²⁻. Furthermore, presence of excess Cl⁻ during synthesis results in decreased %conversion and reduced ECSA, which is opposite from other reported work synthesized at higher temperature and pure solvents. For Pt/C synthesis under mild conditions, 100 °C and 30 vol% EG in water as solvent, presence of OH⁻ during synthesis decreases the ECSA and hence increases the Pt nanoparticle size and change of catalyst surface structure. Finally, a method to get insights into the surface structure of Pt-nanoparticles through analysis of the H-adsorption/H-desorption peaks has been proposed.

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Metallo-porphyry-based frameworks have been utilized to construct single-atom catalysts (SACs), but their use in the fabrication of dual-atom catalysts (DACs) for the nitrogen reduction reaction (NRR) electrocatalytically is limited. Herein, a binuclear phthalocyanine (bN-Pc) was assessed based on a theoretical model to construct dual-atom systems (MoMo-bN-Pc, WW-bN-Pc, and MoW-bN-Pc) along with NRR activity and respective mechanisms, exploiting density functional theory (DFT) calculations. A cis-bridged N₂-adduct, with N-atoms coordinating on both sides, resulted in these dual-atom systems, keeping adjacent metals in close proximity. Gibbs free energy studies revealed that the potential-determining step (PDS) for these catalysts appeared to be the protonation of adsorbed N₂ on dual-atom sites (*N₂H). Following the enzymatic pathway, MoW-bN-Pc had the lowest limiting potential (− 0.32 V) than other systems, indicating its higher NRR activity. The synergistic orbital coupling between Mo(4d) and W(5d) due to their intimate proximity significantly raised the energy of the highest occupied molecular orbital of Mo to facilitate the electron donation to the antibonding orbital of N₂, endowing the NRR of MoW-bN-Pc as compared to other systems. This work is sure to create interest for future studies on the construction of DAC-based active sites using molecular models.

The photoelectrocatalytic conversion of biomethane/biogas using semiconductor materials is a promising method for production of green H₂, the fuel of the future. In this work, TiO₂ nanotubes (TiO₂NTs) prepared by electrochemical anodization were modified with Pt and Pd nanoparticles by electrochemical deposition using cyclic voltammetry, producing TiO₂NTs/Pt and TiO₂NTs/Pd catalysts, respectively. Evaluation of the morphology, composition, and crystallinity of the materials employed scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The photoactivities of the electrodes were studied using linear scanning voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. The introduction of Pt and Pd on the TiO₂NTs resulted in electrodes that presented excellent photogenerated charge separation and transfer properties. In the presence of methane, the current densities obtained increased further, by around 2.23- and 2.95-fold for the TiO₂NTs/Pt and TiO₂NTs/Pd electrodes, respectively, compared to the pure TiO₂NTs, confirming the capacity of CH₄ to act as a hole scavenger. The maximum amounts of H₂ obtained from the photoelectrocatalytic conversion of methane were 120.7, 304.7, and 393 mmol.cm⁻² for the TiO₂NTs, TiO₂NTs/Pt, and TiO₂NTs/Pd electrodes, respectively, clearly showing the positive contribution of the metallic nanoparticles electrodeposited on the TiO₂NTs surface. A lower amount of H₂ was produced in the photoelectrocatalytic conversion of biogas, with the possible occurrence of additional reactions, such as the reduction of CO₂.

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