Electrochemical sensing platform using cerium tungstate for highly sensitive sensing of chromium in water

Abstract

Chromium, in some forms and large amounts, can be hazardous to human health and the environment. In particular, hexavalent chromium Cr(VI) and its derivatives are the most poisonous forms of Cr, whose toxicity depends on its oxidation state. Herein, cerium tungstate (CeW) is demonstrated as an efficient sensing material for Cr(VI) detection in aqueous medium. Two different surfactants are used to hydrothermally synthesize flake-like and sphere-like morphology. The flake-like morphology shows excellent Cr(VI) detection ability owing to its larger surface area, oxygen vacancy defects, and electrochemically active surface area. The sensitivity and limit of detection (LoD) value of the CeW nanoflakes are found to be 0.71 μA/ppb and 6.1 ppb, respectively. The LoD is lower than the WHO recommended standard value, which suggests that the synthesized material can be used for determining Cr(VI) concentration in domestic and potable water. The presence of different ions, such as Fe3+, Zn2+, Cu2+, Hg2+and Pb2+in the medium is found not interfere the Cr(VI) detection ability of CeW nanoflakes and thereby enhancing its practical applicability in Cr(VI) detection.