Theoretical and experimental studies of tin electrodeposition

Abstract

Tin electrodeposition from acid solutions consumes less electrical energy and produces bright Sn plating. However, the coating obtained has poor quality. Consequently, organic additives are added to improve the effeteness of deposit. In the current article, the effect of decyl glucoside, as a green additive, on tin electrodeposition in the acid sulphate medium was studied by the combination of theoretical and experimental approaches. The polarization curves indicate that the tested additive is not electroactive. Likewise, this compound modifies the current density and the activation energy of tin reduction as well as the hydrogen evolution and the apparent diffusion coefficient. The additive does not affect the electron transfer during the electrodeposition process. The fraction of the electrode surface covered by the adsorbed additive molecules, at the peak potential, is 0.545. The reduction of Sn2+ ions is diffusion-controlled reaction. SEM and XRD analyses show that the additive improves the quality and change the preferred orientation of the tin deposited. The most relevant quantum chemical parameters of the additive were also calculated. The Parr functions and molecular electrostatic potential plot show that the heterocyclic ring is the most active part of the molecule. In addition, molecular dynamics simulation reveals the optimized adsorption configuration of the tested molecule on the iron surface and emphasizes the spontaneity and the physical nature of the additive adsorption. Theoretical studies are in good agreement with the experimental results.