Search

Made available in DSpace on 2021-06-26T04:30:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fapergs/PqG 2017 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The increase in global energy demand, with consequent environmental effects caused by the extensive use of fossil fuels, resulted in the intensification of studies concerning the development of new sustainable processes of energy storage. Aiming to solve issues like complex fabrication processes, high cost and side effects on the environment, the use of activated carbons derived from residual biomass as electrodes for energy storage devices has attracted much attention. In this study, activated carbons derived from citrus bergamia peels activated with phosphoric acid (AC - H3PO4) and manganese nitrate (AC - Mn3O4) were produced, and its chemical, structural, morphological and electrochemical properties were evaluated as electrodes for supercapacitor. The electrochemical properties were studied by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge, revealing the excellent performance of both AC - H3PO4 and AC - Mn3O4 , materials. The maximum value of specific capacitance was achieved by AC - Mn3O4, reaching 289 F.g(-1) at a current density of 0.1 Asg(-1). Outstanding results regarding energy density in ionic liquid electrolyte were also obtained, with values of 50.8 Wh kg(-1) at a power density of 240 W kg(-1). Univ Fed Pelotas, Grad Program Mat Sci & Engn, Technol Dev Ctr, BR-96010000 Pelotas, RS, Brazil Fed Univ Rio Grande FURG, PPMec, Campus Carreiros,Italia Ave,Km 8, BR-96203E90 Rio Grande, RS, Brazil Univ Fed Pelotas, Lab Lipid & Bioorgan, Av Eliseu Macieu Bldg 31, BR-96010900 Capao do Leao, RS, Brazil Sao Paulo State Univ, Interdisciplinary Lab Ceram, IQ, Av Prof 16,Francisco Degni,55, BR-14800060 Araraquara, SP, Brazil Sao Paulo State Univ, Interdisciplinary Lab Ceram, IQ, Av Prof 16,Francisco Degni,55, BR-14800060 Araraquara, SP, Brazil CAPES: 001 Fapergs/PqG 2017: 17/25510001157-0 FAPESP: 2015/5015/50526-4

A method based on microwave-induced combustion (MIC) was applied for the decomposition of different types of edible seaweed (Nori, Hijiki and Wakame) for subsequent determination of bromine and iodine by inductively coupled plasma mass spectrometry (ICP-MS). Decomposition of 500 mg of each sample was achieved in less than 30 min. A single and diluted solution (150 mmol L-1 (NH4)2CO3) was used for the absorption of both analytes and a reflux step of 5 min was applied to improve analyte recoveries. Accuracy was evaluated using certified reference materials and agreement was between 103 and 108% for both elements.