Study the effects of methane disulfonic acid sodium salt on Cr (VI) reduction using rotating disk electrode

Abstract

Abstract Chromium (VI) electroplating plays a vital role in the surface engineering industry for metallic materials due to its high hardness and excellent chemical stability. However, the reduction of Cr (VI) is a series of complex reactions that exhibits low current efficiency. As such, this low current efficiency in the process poses a significant challenge in the adoption of CR (VI) electroplating in the surface engineering industry. Methane disulfonic acid sodium salt (MDAS) is an essential catalyst for Cr (VI) electroplating. In this work, the effects of MDAS on the current efficiency of Cr (VI) electroplating process is studied. It is discovered that the current efficiency increases to about 17% when 4–6 g l−1 MDAS is added in the bath, which is an improvement over the current efficiency of 12% for its counterpart without MDAS. Furthermore, rotating disk electrode method is employed to investigate its interaction mechanism with regards to the reactions which have occurred during this process. It indicates that MDAS demonstrates a remarkable catalytic ability towards the electrochemical reaction which occurs at the lower-potential peak. This lower potential peak corresponds to the electrochemical reaction of Cr (VI) to Cr (0) or Cr (III) to Cr (0).