The role of glycine in the iron-phosphorous alloy electrodeposition

Abstract

The influence of glycine on the iron phosphorous alloy electrodeposition was investigated by electrochemical quartz microbalance (EQMB), in-situ external reflection FTIR spectroscopy, and electrochemical impedance spectroscopy (EIS) measurements. An increase of glycine concentration leads to a decrease of the iron-phosphorous alloy electrodeposition rate and an increase of hydrogen evolution. Strong adsorption of glycine species, such as H 2 (gly) þ , H(gly) ± or/and Fe(gly) þ , have been observed during the hydrogen evolution and the Fe-P deposition reaction. Due to the concurrent hydrogen evolution the pH attains higher values at the interface than in the electrolyte bulk (pH2.5). The formation of adsorbed Fe(gly) þ and of the chelate complex Fe(gly) 2 in solution avoids the precipitation of Fe(OH) 2 in the pH range between 2.5 and ca. 7 at the interface. The phosphorous content of the iron phosphorous alloy deposit increases with the glycine concentration. This is due to a lower deposition rate of iron caused by the adsorption of Fe(gly) þ , while the hypophosphite reduction rate to phosphorous increases.

Electrodeposition of Soft Magnetic Fe-W-P Alloy Coatings from an Acidic Electrolyte

“…A negative potential scan in the Fe-W and the Fe-W-P baths at pH 3 resulted in a negative current wave at ca. −0.4 V (Figure 1a), which can be interpreted as hydrogen evolution supported by the measured charge density |∆q| [9]. The absence of any frequency change (∆f), i.e., any mass increase, indicates the generation of a gas uncoupled from the surface.…”

“…It has been shown that the addition of phosphorous can improve the magnetic properties of electrodeposited coatings [7,8]. A detailed study based on electrochemical in-situ techniques led to a mechanistic understanding of the Fe-P alloy electrodeposition [9]. An increase of the P content exerts a beneficial effect on the corrosion resistance [10,11].…”

“…Considering the numerous advantages of Fe-P coatings with high P content [9][10][11], the aim of this work is to explore a new electrolytic bath using sustainable or low quantity hazardous materials, which leads to an increase in the P content in Fe-W-P alloys. Previous studies reported the formation of alloys, where the P content dominates over W. Therefore, we describe the use of a new source of elements and the influence of the chemical environment on the final alloy composition.…”

Modelling and Optimization of Electrodeposited Amorphous Fe-P Alloys Using CCC Design and RSM

“…In addition, the deposit is amorphous when the P content is greater than 8 wt.%. To date, numerous researchers have employed single-factor and orthogonal experiments to study the impacts of different amorphous Fe-P electrodeposition process parameters on the behaviours and properties of deposits [10,11,22,23]. However, there is a lack of quantitative studies on the correlations among parameters, P contents and deposit properties.…”

The Influence of Sodium Tungstate Concentration on the Electrode Reactions at Iron–Tungsten Alloy Electrodeposition

“…The peculiarities mentioned above lead to a need for a detailed investigation of targeted alloy deposition even in the case of simple as possible bath composition., e.g., by using controlled hydrodynamic conditions [31,32] or/and complementary electrochemical techniques (quartz crystal microbalance coupled with electrochemical techniques) [33,34].…”