M. Celalettin Baykul

Deposition potential dependence of composition, microstructure, and surface morphology of electrodeposited Ni–Cu alloy films

Composition, microstructure, and surface morphology of Ni–Cu alloy films electrodeposited at different deposition potentials have been investigated. The microstructural analysis carried out by using X-ray diffraction (XRD) confirmed that all Ni–Cu films are polycrystalline in nature and possess face-centered cubic structure. XRD analysis also revealed that the (111) peak of the Ni–Cu alloy films splits into two as Cu-rich and Ni-rich peaks and the peak intensities change depending on the deposition potential and hence the film composition. Compositional analysis of Ni–Cu films carried out by energy dispersive X-ray spectroscopy showed that Ni content within the films increases as the deposition potential becomes more negative. The morphological analysis performed by using a scanning electron microscopy and an atomic force microscopy revealed that the surface morphology changes significantly with applied deposition potential. Furthermore, a direct correlation is observed between the surface roughness and lattice strain.

Effect of Applied Current Density on Morphological and Structural Properties of Electrodeposited Fe–Cu Films

A detailed study has been carried out to investigate the effect of applied current density on the composition, crystallographic structure, grain size, and surface morphology of Fe–Cu films. X-ray diffraction (XRD) results show that the films consist of a mixture of face-centered cubic (fcc) Cu and body centered cubic (bcc) α-Fe phases. The average crystalline size of both Fe and Cu particles decreases as the applied current density becomes more negative. Compositional analysis of Fe–Cu films indicates that the Fe content within the films increases with decreasing current density towards more negative values. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) have been used to investigate the surface morphology of Fe–Cu films. It is observed that the surface morphology of the films changes from dendritic structure to a cauliflower structure as the applied current density becomes more negative. The surface roughness and grain size of the Fe–Cu films decrease with decreasing applied current density towards more negative values.

Preparation and Characterization of Activated Carbon from Chestnut Shell and its Adsorption Characteristics for Lead

Activated carbons were prepared from chestnut shell by phosphoric acid activation and the prepared activated carbons were used to remove lead(II) from aqueous solutions. The effects of impregnation ratio (IR) and activation temperature on activated carbon production were investigated. The produced activated carbons were characterized by N2 adsorption, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. The highest surface area (1611 m2/g) and total pore volume (0.7819 cm3/g) were obtained at a carbonization temperature of 500°C with an impregnation ratio of 3/1. The resulting activated carbon was used for removal of lead(II) from aqueous solution. The effects of temperature, contact time, and adsorbent dosage were investigated. The adsorption isotherm studies were carried out and the obtained data were analyzed by the Langmuir, Freundlich, and Temkin equations. The rate of adsorption was found to conform to the pseudo-second-order kinetic model. The Langmuir isotherm equation showed better fit for all temperatures and the maximum adsorption capacities of lead(II) was obtained as 138.88 mg/g at 45°C.

Microstructural and morphological characterizations of nanocrystalline Ni–Cu–Fe thin films electrodeposited from electrolytes with different Fe ion concentrations

In the current study, ternary Ni–Cu–Fe thin films have been grown from the electrolytes with different Fe ion concentrations onto indium tin oxide coated glass substrates by galvanostatic electrodeposition at ambient temperature. The microstructural, compositional, and morphological properties have been characterized with respect to Fe ion concentration using X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). EDX results indicated that the Fe content within the films increased and Ni and Cu contents decreased as the Fe ion concentration in the electrolyte was increased. From the XRD analysis, it was observed that the films have two separate, Cu-rich and Ni-rich phases. It was also observed that the phase separation becomes weaker with increasing Fe ion concentration. All of the films have face-centered cubic structure and [111] preferred crystallographic orientation. The texture degree of the Ni-rich (111) phase increased with the Fe ion concentration. SEM and AFM measurements revealed that the surface morphology is considerably affected by the Fe ion concentration. The size of the grains formed on the film surface and the surface roughness decreased as the Fe ion concentration within the electrolyte increased.

Properties of electrodeposited Fe–Cu films grown on ITO coated glass substrates at different electrolyte temperatures

In this study, effect of electrolyte temperature on structural and morphological properties of Fe–Cu films electrodeposited on ITO coated glass substrates has been investigated. Structural analysis carried out by using X-ray diffraction indicated that the films consist of a mixture of face-centered cubic (FCC) Cu and body centered cubic (BCC) α-Fe phases. It was found that the crystalline size of both Fe and Cu increases with increasing electrolyte temperature. Compositional analysis performed using energy dispersive X-ray spectroscopy showed that the Cu content within the films enhances with increasing electrolyte temperature. The surface morphology of Fe–Cu films was studied using a scanning electron microscopy (SEM). SEM results indicated that the surface morphology of Fe–Cu films significantly depends on the electrolyte temperature. The investigation of the residual stress in the films indicated that the residual stress for the FCC Cu is tensile in all films regardless of electrolyte temperature, whereas, for the BCC Fe, it depends on the electrolyte temperature. Correlation between the surface morphology and the residual stress is discussed in terms of the obtained results.

Evolution of surface roughness parameters and microstructure in two-phase nanocrystalline Co–Cu films electrodeposited onto ITO coated glass substrates at different deposition potentials

In the present research, we have studied the effect of deposition potential on the film composition, structural, and morphological properties of the electrodeposited Co–Cu thin films grown onto indium tin oxide coated glass substrates. For this purpose, the properties of the films were analyzed by means of X-ray diffraction, energy dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM) characterization techniques. Structural characterizations showed that all of the Co–Cu films consist of hexagonal close-packed (hcp) Co and face-centered cubic (fcc) Cu phases. The hcp Co (002)/fcc Cu (111) peak intensity ratio was found to increase as the deposition potential decreased towards more negative values. An increase in the Co content in the Co–Cu films was observed as the applied deposition potential was made more negative according to EDX analysis. The decrease of the applied deposition potential towards more negative values also induced a decrease in the average crystallite sizes of both Co and Cu particles. AFM study indicated that a granular structure of the electrodeposited Co–Cu films regardless of deposition potential. As the applied deposition potential was made more negative, the surface roughness and particle size decreased considerably. Besides, two additional roughness parameters, surface kurtosis and the surface skewness were also obtained and discussed by means of the obtained results under the study.

Comparison of Microstructural and Morphological Properties of Electrodeposited Fe-Cu Thin Films with Low and High Fe : Cu Ratio

Fe-Cu films with low and high Fe : Cu ratio have been produced from the electrolytes with different Fe ion concentrations at a constant deposition potential of −1400 mV versus saturated calomel electrode (SCE) by electrodeposition technique onto indium tin oxide (ITO) coated conducting glass substrates. It was observed that the variation of Fe ion concentration in the electrolyte had a very strong influence on the compositional, surface morphological, and microstructural properties of the Fe-Cu films. An increase in the Fe ion concentration within the plating bath increased the Fe content, consequently Fe : Cu ratio within the films. The crystallographic structure analysis showed that the Fe-Cu films had a mixture of face-centered cubic (fcc) Cu and body centered cubic (bcc) α-Fe phases. The average crystallite size decreased with the Fe ion concentration. The film electrodeposited from the electrolyte with low Fe ion concentration exhibited a morphology consisting of dendritic structures. However, the film morphology changed from dendritic structure to cauliflower-like structure at high Fe ion concentration. The surface roughness and grain size were found to decrease significantly with increasing Fe ion concentration in the electrolyte. The significant differences observed in the microstructural and morphological properties caused by the change of Fe ion concentration in the electrolyte were ascribed to the change of Fe : Cu ratio within the films.