Effect of a Natural Brightener, Daphne gnidium L. on the Quality of Nickel Electroplating from Watts Bath

Abstract

Daphne gnidium L. (DGL), a plant known to be rich source of polyphenols, a naturally occurring class of antioxidants, was tested for its ability to play the role of primary and secondary brighteners for electrodeposition of nickel, as a replacement for synthetic brighteners such as glycerol and formaldehyde. A simple and convenient approach was adapted consisting in adding an accurate amount of powdered leaves of Daphne gnidium L. (DGLP) or Daphne gnidium L. leaves extract (DGLE), to the Watts bath, to play the role of brightening agents. Cyclic voltammetry studies revealed that DGLP could inhibit the reaction of nickel reduction and improve the quality of the deposits as efficiently as glycerol and formaldehyde. SEM analyses showed that the micro-cracks decreased and sometimes disappeared from nickel deposits prepared in the presence of DGLP as a brightener. The results of this study show that DGL can be used satisfactorily, with minimum operations as a brightening agent for nickel electrodeposition. The key idea of direct immersion of DGLP in the Watts bath, aimed to the replacement of synthetic brighteners and the reduction of the overall cost of nickel electrodeposition.