Papers by Ernesto Pereira
Solar Energy Materials and Solar Cells, Jan 1, 2004
Thiophene-3-acetic acid has been polymerized in chloroform by a chemical method using FeCl3 as ox... more Thiophene-3-acetic acid has been polymerized in chloroform by a chemical method using FeCl3 as oxidant. The films were prepared casting the solubilized polymer on ITO electrodes and studied using cyclic voltammetry, chronoamperometry and spectroelectrochemistry. During the potential sweep, an electrochromic process is observed in which the film color changes from red to black. High electrochromic efficiency was observed for more than 600 cycles, although it decreases to 73% of the initial value. Until 264 cycles, the electrochromic efficiency at 750 nm is stable and the value is 242 cm2 C−1.
Electrochimica Acta, Jan 1, 2007
The electrodeposition of cobalt from sulphate solutions containing boric acid was investigated us... more The electrodeposition of cobalt from sulphate solutions containing boric acid was investigated using EQCM technique coupled with potentiostatic measurements. The boric acid was added to electrolyte as a buffer to avoid the local pH rise caused by parallel hydrogen evolution reaction (HER). The results showed that the buffer contribution of boric acid is effective in the cobalt electrodeposition at 25 °C; however, cobalt hydroxide is formed simultaneously with cobalt deposition at 48 °C. The M/z values calculated using the Sauerbrey equation and the Faraday Law showed that in the initial stages of deposition at 48 °C, only cobalt deposits were detected, but after 2 s, an important amount of Co(OH)2 started to be formed.
Uploads
Papers by Ernesto Pereira