• Allende, Scarlett
• Zafar, Muhammad Adeel

Abstract

<jats:title>Abstract</jats:title><jats:p>Developing applications for the by-products obtained from waste processing is vital for resource recovery. The synthesis of ZnCl<jats:sub>2</jats:sub>-activated biochar with high electrocatalytic activity was carried out by the microwave-assisted pyrolysis of pineapple peel and subsequent chemical activation process. Activated biochar is employed in the electrochemical sensing of nitrite by drop casting in a glassy carbon electrode (GCE). The activated biochar exhibited a stacked carbon sheet, 254 m<jats:sup>2</jats:sup> g<jats:sup>−1</jats:sup> Brunauer, Emmett and Teller (BET) surface area, 0.076 cm<jats:sup>3</jats:sup> g<jats:sup>−1</jats:sup> pore volume, 189.53 m<jats:sup>2</jats:sup> g<jats:sup>−1</jats:sup> micropore area and oxygen-containing functional groups. The electrochemical impedance spectroscopy of the modified GCE showed a reduced charge transfer resistance of  61%. This is crucial to determine the electrochemical properties of biochar. The sensor showed a significant current response and an excellent limit of detection of 0.97 µmol L<jats:sup>−1</jats:sup>. The modified-activated biochar electrochemical sensor demonstrated high selectivity, reproducibility (RSD=2.4%), and stability (RSD=2.6%).</jats:p><jats:p><jats:bold>Graphical abstract</jats:bold></jats:p>

Topics

• pyrolysis
• impedance spectroscopy
• pore
• surface
• Carbon
• Oxygen
• casting
• activation