Electrochemical signatures of common pitfalls in voltammetric experiments: a practical guide

Voltammetry is one of the most widely used electroanalytical techniques owing to its simplicity, low cost, rapid analysis, and ability to provide mechanistic, kinetic, thermodynamic, and analytical information on various redox systems. During the past decades, it has found various applications in biochemistry, pharmaceutical sciences, environmental monitoring, enzymatic electrochemistry, corrosion research, battery development, nanotechnology, green energy conversion, biosensor design, and in analysis of various biomedical materials, among other applications. Despite the apparent simplicity of voltammetric measurements, reliable interpretation of voltammograms often requires substantial theoretical knowledge and careful consideration of numerous experimental factors that may distort electrochemical responses. Incorrect interpretation of such artifacts may lead to erroneous conclusions regarding reaction mechanisms, electron-transfer kinetics, adsorption processes, catalytic activity, or chemical reactivity. Characteristic voltammetric signatures associated with working and reference electrode problems, working electrode memory effects, ohmic drop, dissolved oxygen interferences, convection, adsorption, crystallization, temperature and pH variations, capacitance effects, instrumental noise, peak overlap, chemical reactions coupled to electron-transfer step, bubble formation, and poor repeatability are systematically illustrated and discussed. For each experimental artifact, the major cause of its origin, characteristic voltammetric appearance, methods for recognition, and practical eliminating strategies are presented. By combining representative voltammograms with mechanistic explanations and practical recommendations, this work aims to improve the quality and interpretation of voltammetric measurements. It represents a valuable educational resource for students and all researchers who use voltammetry.