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 h. 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.

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 Ni^2+/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.