Free-electrodeposited anodic stripping voltammetry sensing of Cu(II) based on Ti3C2Tx MXene/carbon black.

A proof-of-principle concept for free-electrodeposited anodic stripping voltammetry (ASV) sensing of Cu2+ is proposed by using Ti3C2Tx MXene/carbon black (Ti3C2Tx@CB) nanohybrids as electrode materials. Owing to the high adsorption and reduction capability of Ti3C2Tx towards Cu2+, Ti3C2Tx MXene enables Cu2+ to be immobilized and self-reduced directly to form Cu0 on the Ti3C2Tx@CB electrode surface. As a result an oxidation peak current appears from the re-oxidation of Cu0 via differential pulse voltammetry. Carbon black (CB) was introduced to prevent Ti3C2Tx Mxene aggregation and improve the related electron transfer as well as enhance their surface area. After optimizing various conditions, a considerable low limit of detection (4.6 nM) and a wide linear range (0.01–15.0 μM) for Cu2+ were achieved at the working potential from − 0.3 V to 0.0 V (vs SCE). Relative standard deviation (RSD) of eight individual Ti3C2Tx@CB electrodes is 3.72%, and the recoveries from tap water sample and lake water sample were in the ranges of 97.0–108% and 104–107%, respectively.