Herein we report the electrocatalytic activity of boron-doped graphene for the reduction of CO2. Electrolysis takes place at low overpotentials leading exclusively to formate as the product (vis-à-vis benchmark Bi catalyst). Computational studies reveal mechanistic details of CO2 adsorption and subsequent conversion to formic acid/formate.
View Article and Find Full Text PDFHerein, we report the first synthesis of a light-weight macroporous 3-D alloy monolith of Ni-Fe/C using synergism between polydopamine (pDA) and polyurethane (pU); in situ formed polyurethane (pU) enables efficient mixing of pDA (carbon source) and Ni-FeOx resulting in Ni-Fe alloy monoliths at a temperature as low as ∼600 °C. The monolithic Ni-Fe/C exhibits enhanced oxygen evolution activity.
View Article and Find Full Text PDFWe discovered using SECM of the electro-reduction of CO2 on a Au substrate in CO2-saturated KHCO3 solutions that (i) formate comes solely from the direct reduction of bicarbonate; and (ii) CO forms only from CO2 reduction (under low pH conditions) and at higher applied potentials. The results point to the possibility of the selective reduction of CO2 to the formate product.
View Article and Find Full Text PDFIn this study the performance enhancement effect of structural ordering for the oxygen reduction reaction (ORR) is systematically studied. Two samples of PtCu3 nanoparticles embedded on a graphitic carbon support are carefully prepared with identical initial composition, particle dispersion and size distribution, yet with different degrees of structural ordering. Thus we can eliminate all coinciding effects and unambiguously relate the improved activity of the ORR and more importantly the enhanced stability to the ordered nanostructure.
View Article and Find Full Text PDFHydroxyl radicals arising from the Fenton reagent remove metastable surface gold atoms (low coordinated high-energy surface atoms) on the Au surface, thus precluding the formation of stable oxides. The resultant smooth surface, upon hydroxyl-radical activation, electrocatalyzes oxygen evolution reaction in 0.1 M NaOH at overpotentials lowered by 190 mV @ 10 mA cm(-2).
View Article and Find Full Text PDFIn this work, the determination of cadmium has been attempted using an indium film electrode in the presence of bromide ions as an additive, for the first time. The electrode was prepared in situ on a glassy carbon substrate and employed in combination with square wave anodic stripping voltammetry. The purpose of having bromide ions is to enhance the analytical value of cadmium detection.
View Article and Find Full Text PDFIn this work, we reported for the first time, a facile and one step synthesis of gold nanoparticles from HAuCl(4), employing tetraphenylborate as the reducing agent. The synthesis is not only facile but also yields "dumb-bell-shaped"particles. This shape appears to arise from a possible emulsion of the products of oxidation/decomposition of tetraphenylborate by HAuCl(4), surrounding the particle.
View Article and Find Full Text PDFPoly(3,4-ethylenedioxythiophene) has been used to immobilize both the metal particle catalyst and the reagent, (cyano-)borohydride, by simple doping and chemical reduction. These films have shown catalytic activity in the hydrogenation of nitrophenol and electro-oxidation of methanol, formic acid and borohydride.
View Article and Find Full Text PDFGradual, yet a great leap: electrosynthesized surfactant-stabilized gold atomic clusters (AuACs; Au(n) , 5≤n≤13) electrocatalyze the oxygen reduction reaction (ORR) in acid solution at low overpotentials. Depending on the surfactant concentration, the ORR mechanism gradually transits from a direct four-electron to a two-electron pathway (see picture; SHE=standard hydrogen electrode), which suggests the transformation of atomic clusters into nanoparticles.
View Article and Find Full Text PDFThis paper describes the formation of catalytically active thin films of Pt, Pt/Au, and Pt/Ru on gold substrates stabilized by amine-terminated polyamidoamine (PAMAM) dendrimers. A monolayer of dendrimer is initially self-assembled on the gold substrate, which serves as a template for the growth of catalytically active thin films. As dendrimers contain tens to hundreds of functional groups at the periphery, the aggregate strength of the multidentate interactions with the gold substrate leads to the formation of robust films.
View Article and Find Full Text PDFHerein, we report a one-pot synthesis of highly stable Au nanoparticles (AuNPs) using 3,4-ethylenedioxythiophene (EDOT) as a reductant and polystyrene sulfonate (PSS-) as a dopant for PEDOT and particle stabilizer. The synthesis demonstrated in this work entails the reduction of HAuCl4 using EDOT in the presence of PSS-. The formation of AuNPs with concomitant EDOT oxidation is followed by UV-vis spectroscopy at various time intervals.
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