A hierarchical composite based on the modified reduced graphene oxide with platinum-nickel decorated polyaniline nano-spheres (rGO/PANI@PtNi) was facilely prepared via microwave-assisted self-reduction for an application in nonenzymatic hydrogen peroxide (H2O2) detection. Compared to the pristine rGO, the composite exhibited a much tougher surface due to the stacking of conductive PANI nano-spheres on rGO sheets, leading to good dispersion of PtNi nanoparticles and a large active area. Furthermore, the multi-valance Ni2+/3+ in the PtNi particles effectively promoted the catalytic property of Pt sites and facilitated a superior electrochemical performance of PtNi alloy than that of neat Pt. Owing to the synergistic effect of the improved electrical conductivity and the promoted electrocatalytical property, the modified glassy carbon electrode (GCE) with rGO/PANI@PtNi nanocomposite displayed an outstanding electrochemical sensitivity towards H2O2 with a fast response time (<2 s), a wide linear range (0.1–126.4 mM), a low detection limit (0.5 µM), as well as a long-life stability for one week without obvious degradation. This novel strategy opens a novel and promising approach to design high performance sensors for H2O2 detection.
We fabricated one fibrous-membrane type of flexible and lightweight supported catalyst via loading platinum–nickel nanoparticles (PtNi NPs) directly on the polydopamine-coated polymethylmethacrylate electrospun-fibers (PMMA@PDA). The polymer support with the PDA layer provided numerous active sites, leading to well-monodispersed and sized PtNi NPs on the nanofibers. Through the rational design of PtNi NPs, the resultant catalyst system exhibited 90% conversion for decomposing HCHO (10 ppm) at room temperature with only a low dosage (0.02 g), retaining the high activity for 100 hours. This superior catalytic performance stems from the formate oxidation, which was the key intermediate during HCHO decomposition, and was promoted by the existence of a sufficient Pt–OH–Ni interface in the PtNi NPs with an appropriate Pt/Ni ratio of 1:5. Such tailored Pt-based nanoparticles ideally work together with the polymer nanofibers as a support for catalytic reaction. Compared with classical catalysts, our system can handle a comparable efficiency with much lower air resistance and remarkably lower dosage. Furthermore, the membrane-like morphology provides easy handling and minimizes the leaching of catalyst nanoparticles.
An efficient and economical electrocatalyst as kinetic support is key to electrochemical reactions. For this reason, chemists have been working to investigate the basic changing of chemical principles when the system is confined in limited space with nanometer-scale dimensions or sub-microliter volumes. Inspired by biological research, the design and construction of a closed reaction environment, namely the reactor, has attracted more and more interest in chemistry, biology, and materials science. In particular, nanoreactors became a high-profile rising star and different types of nanoreactors have been fabricated. Compared with the traditional particle nanoreactor, the onedimensional (1D) carbon-based nanoreactor prepared by the electrospinning process has better electrolyte diffusion, charge transfer capabilities, and outstanding catalytic activity and selectivity than the traditional particle catalyst which has great application potential in various electrochemical catalytic reactions.
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