We report a virus-incorporated biological template (biotemplate) on electrode surfaces and its use in electrochemical nucleation of metal nanocomposites as an electrocatalytic material for energy applications. The biotemplate was developed with M13 virus (M13) incorporated in a silicate sol-gel matrix as a scaffold to nucleate Au-Pt alloy nanostructures by electrodeposition, together with reduced graphene oxide (rGO). The phage when engineered with Y3E peptides could nucleate Au-Pt alloy nanostructures, which ensured adequate packing density, simultaneous stabilization of rGO, and a significantly increased electrochemically active surface area. Investigation of the electrocatalytic activity of the resulting sol-gel composite catalyst toward methanol oxidation in an alkaline medium showed that this catalyst had mass activity greater than that of the biotemplate containing wild-type M13 and that of monometallic Pt and other Au-Pt nanostructures with different compositions and supports. M13 in the nanocomposite materials provided a close contact between the Au-Pt alloy nanostructures and rGO. In addition, it facilitated the availability of an OH-rich environment to the catalyst. As a result, efficient electron transfer and a synergistic catalytic effect of the Au and Pt in the alloy nanostructures toward methanol oxidation were observed. Our nanocomposite synthesis on the novel biotemplate and its application might be useful for developing novel clean and green energy-generating and energy-storage materials.
Herein, we report a facile synthetic strategy for the in situ growth of Prussian blue nanostructures (PB NSs) at the amine-functionalized silicate sol-gel matrix (TPDT)-RGO composite via the electrostatic interaction. Subsequently, Pt nanostructures are electrodeposited onto the preformed ITO/TPDT-RGO-PB electrode to prepare the RGO/PB/Pt catalyst. The significance of the present method is that the PB NSs are in situ grown by interconnecting the RGO layers, leading to 3D cage-like porous nanostructure. The modified electrodes are characterized by FESEM, EDAX, XRD, XPS, and electrochemical techniques. The RGO/PB/Pt catalyst exhibits synergistic electrocatalytic activity and high stability toward methanol oxidation. The porous nature of the TPDT and PB and unique electron-transfer mediating behavior of PB integrated with RGO in the presence of Pt nanostructures facilitated synergistic electrocatalytic activity for methanol oxidation.
Concurrent electrocatalysis and sensing of hydrazine, sulfite ions, and nitrite ions in a mixture were studied using electrodes modified by electrodeposited Au nanostructures (NSs). The β-cyclodextrin-mixed silicate sol-gel composite was dropcasted on the electrode surface and nucleation guided by β-cyclodextrin occurred, followed by the electrodeposition of Au NSs. The additive, β-cyclodextrin, played an evident role as a structure-directing agent; thus, small raspberry-like Au NSs were obtained. The modified electrodes were characterized by surface characterization techniques and electrochemical methods. The Au NSs-modified electrodes effciently electrocatalyzed the oxidation of toxic molecules such as hydrazine and sulfite and nitrite ions even in the absence of any other electron transfer mediator or enzyme immobilization. Wellresolved oxidation peaks along with decreased overpotentials were noticed during the electrooxidation process. The fabricated Au nanostructured electrode clearly distinguished the electrooxidation peaks of each of the three analytes from their mixture.
There is a growing demand for simple, cost-effective, and accurate analytical tools to determine the concentrations of biological and environmental compounds. In this study, a stable electroactive thin film of cobalt hexacyanoferrate (Cohcf) was prepared as an in situ chemical precipitant using electrostatic adsorption of Co 2 + on a silicate sol-gel matrix (SSG)-modified indium tin oxide electrode pre-adsorbed with [Fe(CN) 6 ] 3 − ions. The modified electrode was characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical techniques. Electrocatalytic oxidation of hydrazine on the modified electrode was studied. An electrochemical sensor for hydrazine was constructed on the SSG-Cohcf-modified electrode. The oxidation peak currents showed a linear relationship with the hydrazine concentration. This study provides insight into the in situ growth and stability behavior of Cohcf nanostructures and has implications for the design and development of advanced electrode materials for fuel cells and sensor applications.
There is a growing demand for simple, cost-effective, and accurate analytical tools to determine the concentrations of biological and environmental compounds. In this study, a stable electroactive thin film of cobalt hexacyanoferrate (Cohcf) was prepared as an in situ chemical precipitant using electrostatic adsorption of Co − ions. The modified electrode was characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical techniques. Electrocatalytic oxidation of hydrazine on the modified electrode was studied. An electrochemical sensor for hydrazine was constructed on the SSG-Cohcf-modified electrode. The oxidation peak currents showed a linear relationship with the hydrazine concentration. This study provides insight into the in situ growth and stability behavior of Cohcf nanostructures and has implications for the design and development of advanced electrode materials for fuel cells and sensor applications.
Concurrent electrocatalysis and sensing of hydrazine, sulfite ions, and nitrite ions in a mixture were studied using electrodes modified by electrodeposited Au nanostructures (NSs). The β-cyclodextrin-mixed silicate sol-gel composite was dropcasted on the electrode surface and nucleation guided by β-cyclodextrin occurred, followed by the electrodeposition of Au NSs. The additive, β-cyclodextrin, played an evident role as a structure-directing agent; thus, small raspberry-like Au NSs were obtained. The modified electrodes were characterized by surface characterization techniques and electrochemical methods. The Au NSs-modified electrodes effciently electrocatalyzed the oxidation of toxic molecules such as hydrazine and sulfite and nitrite ions even in the absence of any other electron transfer mediator or enzyme immobilization. Wellresolved oxidation peaks along with decreased overpotentials were noticed during the electrooxidation process. The fabricated Au nanostructured electrode clearly distinguished the electrooxidation peaks of each of the three analytes from their mixture.
We report a synthesis for in-situ growth of Prussian blue nanostructures (PB NSs) at the amine functionalized silicate sol–gel matrix (TPDT)–RGO composite via the electrostatic interaction. Pt nanostructures are electrodeposited onto the preformed ITO/TPDT–RGO–PB electrode to prepare the RGO/PB/Pt catalyst. The significance of the present method is that the PB NSs are in-situ grown by inter-connecting the RGO layers, led to 3D porous nanostructure. The modified electrodes are characterized by FESEM, EDAX, XRD, XPS and electrochemical techniques. The RGO/PB/Pt catalyst exhibits synergistic electrocatalytic activity and high stability towards methanol oxidation. The porous nature of the TPDT and PB, and unique electron transfer mediating behavior of PB integrated with RGO in the presence of Pt nanostructures, facilitated synergistic electrocatalytic activity for methanol oxidation.
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