An Electrochemical Sensor Based on a Porous Biochar/Cuprous Oxide

Mercuric ion (Hg[sup.2+]) in aqueous media is extremely toxic to the environment and organisms. Therefore, the ultra-trace electrochemical determination of Hg[sup.2+] in the environment is of critical importance. In this work, a new electrochemical Hg[sup.2+] sensing platform based on porous activated carbon (BC/Cu[sub.2]O) modified with cuprous oxide was developed using a simple impregnation pyrolysis method. Differential pulse anodic stripping voltammetry (DPASV) was used to investigate the sensing capability of the BC/Cu[sub.2]O electrode towards Hg[sup.2+]. Due to the excellent conductivity and large specific surface area of BC, and the excellent catalytic activity of Cu[sub.2]O nanoparticles, the prepared BC/Cu[sub.2]O electrode exhibited excellent electrochemical activity. The high sensitivity of the proposed system resulted in a low detection limit of 0.3 ng·L[sup.−1] and a wide linear response in the ranges from 1.0 ng·L[sup.−1] to 1.0 mg·L[sup.−1]. In addition, this sensor was found to have good accuracy, acceptable precision, and reproducibility. All of these results show that the BC/Cu[sub.2]O composite is a promising material for Hg[sup.2+] electrochemical detection.