High-surface-area carbon-based capacitors exhibit significant advantages relative to conventional graphite-based systems, such as high power density, low weight, and mechanical flexibility. In this work, novel porous carbon-based electrodes were obtained from commercial cotton fibers (CFs) impregnated with graphene oxide (GO) at different dipping times. A subsequent thermal treatment under inert atmosphere conditions enables the synthesis of electrodes based on reduced GO (RGO) supported on carbon fibers. Those synthetized with 15 min and 30 min of dipping time displayed high specific capacitance given their optimal micro-/ mesoporosity ratio. Particularly, the RGO/CCF15A supercapacitor reports a remarkable specific capacitance of 74.1 F g−1 at 0.2 A g−1 and a high cycling stability with a 97.7% capacitive retention, making this electrode a promising candidate for supercapacitor desi...

Se presenta detalladamente el desarrollo de un prototipo de medidor autónomo de bajo costo, para la determinación de plomo (II) y otros metales pesados disueltos en agua, así como de pH, conductividad y temperatura. El prototipo incluye un potenciostato, operado de manera autónoma por un micro-controlador, así como un sistema de comunicación mediante tecnología GSM, en la modalidad de mensajes de texto. Se muestran y discuten los resultados experimentales, obtenidos en condiciones de campo, en un puquio del río Lurín. Los resultados indican concentraciones de Pb(II), Cd(II), Cu(II) y Hg(II), por debajo de 5 µg/L, así como pH de 7,3 y conductividad específica de 14 µS/cm. La presente publicación está basada en el informe final del proyecto PROCYT 308 2011 financiado por CONCYTEC.

This work reports the fabrication of a novel electrochemical sensor for the detection of the complex ion [Cu(CN)3](aq)2−, one of the main components of the effluents from cyanide alkaline copper plating baths. This sensor was prepared by using a surface modified glassy carbon (GC) electrode with 1,8-dihydroxyantroquinone (1,8-DHAQ). It was characterized by electrochemical impedance, Raman spectroscopy and UV–Visible spectroscopy. The electrochemical detection of [Cu(CN)3](aq)2−was performed by differential pulse voltammetry. The 1,8-DHAQ/GC electrochemical sensor exhibits good reproducibility and a linear range of 5.50 × 10−7–3.81 × 10−6 mol L−1, with a detection limit (LOD) of 1.20 × 10−6 mol L−1, quantification limit (LOQ) of 3.97 × 10−6 mol L−1, and robustness to interfering Cl−, NO3−, SO42− y CO32− ions. Finally, a DFT approach suggests an almost par...