Study the effect of ammonia addition on the mechanism and properties of electrochemical deposition of silver and nickel alloy

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Study the effect of ammonia addition on the mechanism and properties of electrochemical deposition of silver and nickel alloy

Annotation

Ag-Ni alloy films were electrodepositedfrom ammonia solution on copper substrates, at different material ratios and current densities. The study of electrical conductivity and pH confirmed the formation of complexes with silver and nickel.The best ratio [Ag:Ni] [1:10]. X-ray diffraction (XRD) with CuKa1 radiation was used to investigate the crystal structure.

Keywords: Electrodeposition <silver and nickel alloy < ammonia < complex.

Аль хури. М Магистрант на втором курсе Колледжа Наук - Химический факультет - Физическаяспециализация - в

Университете Аль-Баас - Хомс - Сирия

Профессор Диб Бакирраздел (физическойхимии) Научныйколледж - Университет

Аль-Баас - Хомс - СирияПрофессор Джихад Аль-Вехбираздел (физическойхимии), специализация по термодинамике, Колледж

наук - Университет Аль-Баас - Хомс - Сирия

Изучение эффекта добавка аммонии к механизму и свойствам электрохимического особенности серебра и никеля сплава

Аннотация: Пленки сплава Ag- Niбыли электроосаждены из раствора аммиака на медные подложки при различных соотношениях материалов и плотностей тока. Исследование электропроводности и рН подтвердило образование комплексов с серебром и никелем. Наилучшее соотношение [Ag:Ni] [1:10]. Рентгеновская дифракция (XRD) с CuKal-излучением использовалась для исследования кристаллической структуры.

Ключевые слова: электроосаждение сплав серебра и никеля `аммиака < комплекс. x-ray diffraction ammonia electrical conductivity

Introduction

Electro-chemical deposition of alloys: Its the electrochemical deposition of two or more metals simultaneously.

Importance of Electroplating: Shows a mix of two or three metals or more physical or chemical specifications (corrosion resistance, decorative enhancers, high hardness, low friction, high heat resistance and beautiful appearance): Cu- Ni ,Co- Ag, Fe-Pt^[1-3].

Ag-Ni alloys or bimetallic structures are of technological interest due to their remarkable catalytic, electrical, and magnetic properties ^[4].

Standard latency is markedly different, as is the case for silver (Ag) and nickel (Ni) where:

E°(Ag⁺/Ag)=+0.779V , E°(Ni⁺²/Ni)=-0.250 V The most effective method for converging standard potentials is the formation of fixed complexes, and the correlations are selected so that with the metal ion with the lowest negative potentials they form more stable complexes than those formed with the metal ion with the most negative latency. This leads to the convergence of the deposition potentials of these metals, commonly used cyanide complexes and ammonia ^[5].

Experiment

Nickel - silver alloys were electrodeposited on copper using direct current (DC) . The copper samples used were 3cm in length, and 3cm in width with 2 mm thickness. Ag-Ni deposition from non-complexing solutions was investigated using a sulfate- based electrolyte, with various concentrations of AgNO3 (0.01M) and NiSO4.6H2O (0.01-0.1M); a typical solution contained (0.01M) AgNO3, (0.1M) NiSO4.6H2O, and the pH was kept at 10.2. Ammonia was chosen due to its ability to complex Ag(I),Ni(II) .X-ray diffraction (XRD) with Cu Ka1 radiation (1=1.54060 A° ) in the 0/20 geometry was used to investigate the crystal structure.

Results and discussion

S Study of the correlation of ammonia with Ag+ silver ions by physical and chemical methods: 1: Method of Measuring pH Solution:

Figure (1): Determination of the correlation ratio in the ammonia silver complex

by measuring the solution of pH 2: Electrical conductivity measurement method:

Ammonia volume(ml)

Figure (2): Determination of the correlation ratio in the ammonia silver complex by electrical conductivity

By studying the correlation between the silver and ammonia ions in the ammonia silver complex of pH and electrical conductivity, we find that the correlation we obtained experimentally in both methods is [1: 2] ^[6]. According to the equation:

Ag⁺ + 2NH3 ^[Ag(NH3)2]⁺ (1)

S Study of the correlation ratio of ammonia with Ni+² ions by physical and chemical

Figure (3): Determination of the correlation ratio in the ammonia nickel complex by measuring the solution of pH 2: Electrical conductivity measurement method:

Figure (4): Determination of the percentage of binding in the ammonia nickel complex by electrical conductivity

By studying the correlation between the nickel and ammonia ions in the ammonia nickel complex in both pH and electrical conductivity, we find that the correlation we obtained experimentally in both methods is [1: 6]^[7,8].

Ni(H2O)6⁺² + 6NH3 ^[Ni (NH3>]⁺² + 6H2O (2)

S Study the nickel-silver ratio in the presence of ammonia: The results are

According to the electro-crystallization theory. The faster nucleation rate reduces the particle sizes of the deposited film ^[9,10], because the fine particle sizes increase the specific area or curvature that promotes the miscibility of the constituent elements ^{[11, 12]}. This phenomenon is known as the Gibbs-Thomson effect.

S XRD (X-ray diffraction) analysis of the Ag-Ni film formed by the presence of a

Figure (5): XRD spectrum of Ni-Ag film formed from AgNO3 solution with 0.01M concentration, NiSO4 solution with 0.1M concentration with NH4OH ammonia pH(10.2).

The XRD study compared to JCPDS showed that there are strong clear peaks due to both Ni and Ag which correspond to 20 diffraction angles estimated in degrees and equal to the following values ^[13,14]: (38.08 ° -44.3 ° -50.32 ° -74.04 ° - 89.8 °) Which corresponds to the highest intensity of the peaks, ie, the most intense and this is proof that they contain the heavier atoms in the film because the heavier atoms are responsible for stronger intensities, taking into account the number of electrons (electronic density in the crystal.

Conclusions

Physico-chemical study (measurement of pH and electrical conductivity) showed the correlation rate in the ammonia silver complex [1: 1] and in the ammonia nickel complex [1:6].

1) We reached the best ratio between silver and nickel [1:10]), in the current density

2.1 mA/cm².

2) The XRD spectrum confirmed of crystalline morphology of the two metals (Ag - Ni).

References

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