Activated biochar: Preparation, characterization and electroanalytical application in an alternative strategy of nickel determination

作者：Kalinke Cristiane; Oliveira Paulo Roberto; Oliveira Geovane Arruda; Mangrich Antonio Salvio; Marcolino Junior Luiz H; Bergamini Marcio F^*

来源：Analytica Chimica Acta, 2017, 983: 103-111.

DOI：10.1016/j.aca.2017.06.025

• Activated biochar
• Chemical activation
• Nickel
• Carbon paste electrode
• Adsorptive stripping analysis

This work reports for the first time the use of chemically activated biochar as electrode modifier for nickel determination. The biochar activation was performed by refluxing with HNO3, which promoted a higher nickel preconcentration compared to unmodified and modified biochar precursor electrodes. Morphological and structural characterization revealed the increase of surface acid groups, surface area and porosity of biochar after activation. Nickel determination was investigated adopting an alternative voltammetric methodology based on monitoring the Ni(II)/Ni(III) redox couple. In the proposed method, it was not necessary to use a complexing agent and the biochar itself was responsible for the analyte preconcentration. A linear response for Ni(II) concentration range from 1.0 to 30 mu mol L-1 and a limit of detection of 0.25 mu mol L-1 were obtained. The method was successfully applied for Ni(II) determination in spiked samples of bioethanol fuel and discharge water, with recoveries values between 103 and 109%.

• 出版日期2017-8-29