Some factors affecting on the composition of CeO2 and CuO in Ni-CeO2-CuO composite plating coating

Hóa học & Môi trường<br /> <br /> SOME FACTORS AFFECTING ON THE COMPOSITION OF CeO2<br /> AND CuO IN Ni-CeO2-CuO COMPOSITE PLATING COATING<br /> Mai Van Phuoc*, Nguyen Duc Hung<br /> Abstract: In this paper, some factors affecting the total content of CeO2 and<br /> CuO particles in Ni-CeO2-CuO composite plating coating by using electroplating<br /> method from nickel sulfate solution are shown. The total content of above regarded<br /> particles in the composite plating solution was changed from 2 to 16 g/L. Some<br /> other parameters such as cathode current density and stirring speed were changed<br /> from 0.5 to 4 A/dm2 and from 200 to 1000 rpm, respectively. Results obtained from<br /> composition analysis and SEM images of the composite coating showed that the<br /> content and distribution of particles on its surface reached the maximum value of<br /> 38.46 % under plating bath condition at current density of 2 A/dm2, 8 g/L content of<br /> CeO2 and CuO in the plating solution, stirring speed of 600 rpm and plating time<br /> for 15 minutes.<br /> Keywords: Nickel composite electroplating; CuO particles; CeO particles; CuO/CeO2 catalyst layer.<br /> <br /> 1. INTRODUCTION<br /> The composite plating layer was created by co-precipitating from the fine solid<br /> particles and plating metal. The fine solid particles such as CeO2 and CuO were dispersed<br /> in the composite plating solution by stirring or bubbling. The composite plating layers<br /> have many advantages such as high hardness, good wear, antifriction and high corrosion<br /> resistance, so they were used in many industries. The properties of composite plating<br /> layers depended largely on the characteristics and content ratio of the fine solid particles<br /> which were formed on the surface of those coating[1-3].<br /> The authors in [4] reported that the catalytic activity of Ni-CeO2-CuO composite<br /> plating layer depended largely on the composition of CeO2 and CuO particles from its<br /> surface. Thus, the focus of this study is the consideration of some plating parameters that<br /> may be affect the composition of the nanoparticles on the surface of composite plating<br /> layer such as concentration of CeO2 and CuO nanoparticles in the electrolyte solution,<br /> plating current density, the rate of stirring and plating time.<br /> 2. EXPERIMENTAL AND METHODS<br /> 2.1. Materials<br /> The nanoparticles such as CeO2 and CuO (99.9%) are provided by Richest Group Ltd.<br /> (Shanghai, China) and Nano Global (Shanghai, China), respectively.<br /> NiSO4, H3BO3, NaOH, H2SO4, NaCl and CH3(CH2)10CH2OSO3Na (Sodium lauryl<br /> sulfate) are the pure Chinese chemicals.<br /> 2.2. Methods<br /> 2.2.1. Ni-CeO2-CuO composite plating method<br /> A nickel plate with dimensions of 20x10x100 mm was applied as the anode. Cathode is<br /> copper (or steel) plate with the dimension of 100x100x0.2 mm. Both of them were cleansed<br /> of oil and grease, washed in water and activated in 10% H2SO4 solution. After cleaning<br /> surface, the sample was plated in the electrolyte solution following data in Table 1.<br /> Samples after plating was washed with water and dried to analyze the content of CeO2<br /> and CuO nanoparticles on the surface of the plating layer.<br /> 2.2.2. Determination of the content of CeO2 and CuO on the plating layer<br /> <br /> <br /> 130 M. V. Phuoc, N. D. Hung, “Some factors affecting on … composite plating coating.”<br /> Nghiên cứu khoa học công nghệ<br /> The composition of CeO2 and CuO on the plating layer was determined by EDX<br /> technique using an Energy-dispersive X-ray spectrometer JSM 6610 LA - Jeol, Japan at<br /> the Institute of Chemistry and Materials.<br /> Table 1. Composition for plating bath and working conditions.<br /> Composition for plating bath Working conditions<br /> Chemicals Concentration Parameters Quantity<br /> in bath (g/L)<br /> NiSO4 300 Current density 0.5 ÷ 4 A/dm2<br /> H3BO3 30 Plating time 5÷30 minutes<br /> Sodium lauryl sulphate 0.1 Stirring speed 200 ÷1000 rpm<br /> CH3(CH2)10CH2OSO3Na<br /> CeO2 particle 2÷8 Temperature of 50 oC<br /> solution<br /> CuO particle 2÷8 pH 5.8÷6.0<br /> 3. RESULTS AND DISCUSSION<br /> 3.1. Effect of cencentration of CeO2 and CuO particles in electrolyte solution on the<br /> composition of CeO2 and CuO particles on the composite plating coating<br /> The content of CeO2 and CuO particles in the electrolyte solution is an important<br /> factor affecting the composition and quality of Ni-CeO2-CuO composite plating layer.<br /> Nanoparticles of CeO2 and CuO are dispersed into solution as a suspension form by<br /> agitation or aeration. The effect of concentration of both CeO2 and CuO particles (2 ÷ 16<br /> g/L, in weight ratio CeO2: CuO = 1:1) in electrolyte solution was considered under the<br /> following condition: current density of 2 A/dm2, plating time for 20 minutes, stirring speed<br /> of 600 rpm, solution temperature of 50 oC. Results of the compositions of CeO2 and CuO<br /> particles in the plating coating are shown in Fig. 1.<br /> 45<br /> Composition of CeO2 and CuO (%)<br /> <br /> <br /> <br /> <br /> 40 35.64 38.46<br /> 35<br /> 30 26.18<br /> 24.41<br /> 25<br /> 20<br /> 15 12.14 12.35 11.32<br /> 10 6.64<br /> 5<br /> 0<br /> 2 4 6 8 10 12 14 16<br /> Concentration of CeO2 and CuO in solution (g/L)<br /> <br /> Figure 1. Compositions of CeO2 and CuO particles in plating versus concentrations of<br /> CeO2 and CuO particles in solution.<br /> When the concentrations of CeO2 and CuO particles in the solution increased from 2 to 8<br /> g/L, the particle content in the plating coating layers increased also, it reached the maximum<br /> value of 38.46 %. It means, the higher the amount of particles in the solution, the greater the<br /> amount of them added to the coating because of more particles transferred to the surface of<br /> cathode. However, if the concentrations of CeO2 and CuO particles were continuously<br /> increased up to 16 g/L, the content of particles in those layers decreased to 6.64 %. This<br /> <br /> <br /> Tạp chí Nghiên cứu KH&CN quân sự, Số Đặc san CBES2, 04 - 2018 131<br />  Hóa học & Môi trường<br /> phenomenon can be explained that the much higher the amount of particles in solution, the<br /> more particles can be self-accumulated leading to not only decreasing the number of them<br /> transported to the cathode but also their transport process may be prevented.<br /> 3.2. Effect of electroplating current density<br /> The content of CeO2 and CuO particles co-precipitated deeply depends on the current<br /> density. The effect of current density and electroplating time to the structure of Ni-CeO2-<br /> CuO plating layer was investigated in the range of 0.5 ÷ 4 A/dm2. Other conditions<br /> composed of plating time for 20 minutes, temperature of 50 oC, stirring speed of 600 rpm<br /> and the concentration of 4 g/L for each kind of CeO2 and CuO particles. The results are<br /> shown in Fig. 2.<br /> 45<br /> Composition of CeO2 and CuO (%)<br /> <br /> <br /> <br /> <br /> 40 38.46 36.12<br /> 34.38<br /> 35<br /> 30<br /> 25 22.36<br /> 20 14.56 13.25<br /> 15 10.08<br /> 8.54<br /> 10<br /> 5<br /> 0<br /> 0.5 1 1.5 2 2.5 3 3.5 4<br /> Current density (A/dm2)<br /> <br /> Figure 2. The effect of current density to the content of CeO2 and CuO particles<br /> in the Ni-CeO2-CuO plating layer.<br /> As can be seen from Fig. 2, the content of CeO2 and CuO particles in the Ni-CeO2-<br /> CuO plating layers increases when current density increases from 0.5 ÷ 2.5 A/dm2, but, it<br /> decreases when the current density moves up to 4 A/dm2. This result can be explained as<br /> follows, at low current density (0.5 ÷ 2.5 A/dm2), the formation of H2 from the reduction<br /> of proton at cathode is insignificant, hence, the particles can easily deposit on the surface<br /> of cathode, therefore, the content of CeO2 and CuO particles in plating layers is high.<br /> However, at high current density (> 2.5 A/dm2), the H2 formation is significant leading to<br /> preventing the formation bonding between metal particles and surface of electrode.<br /> Otherwide, increasing the current density up to ≥ 3 A/dm2 leads to increasing the rate of<br /> Ni2+ reduction but the loaded rate is constant, therefore, the content of particles in plating<br /> layer decreases. The maximum content of CeO2 and CuO particles in plating layer is<br /> reached at current density of 2 A/dm2.<br /> <br /> <br /> <br /> <br /> 1 A/dm2 2 A/dm2 4 A/dm2<br /> Figure 3. SEM images of the surface of samples<br /> plated at different current densities.<br /> <br /> <br /> 132 M. V. Phuoc, N. D. Hung, “Some factors affecting on … composite plating coating.”<br /> Nghiên cứu khoa học công nghệ<br /> The distribution of CeO2 and CuO particles in the coating surface was verified by SEM<br /> images shown in Fig. 3.<br /> From the SEM images in Fig. 3, we can see that the CeO2 and CuO particles are<br /> uniformly distributed in the surface of plating layers at different current densities.<br /> However, the content of metal loaded on the surface of the electrode was also different,<br /> among them the most metal loading was found at the density of 2 A/dm2 and the poorest<br /> one at the current density of 4 A/cm2.<br /> 3.3. Effect of the stirring speed on the content of CeO2 and CuO particles in Ni-CeO2-<br /> CuO composite plating layer<br /> In order to avoid the deposition of CeO2 and CuO particles in the electrolyte solution,<br /> an aeration and/or stirring are required during the electroplating process. Stirring plays a<br /> decisive role in the distribution of the CeO2 and CuO particles in the solution as well as the<br /> transfer of these particles to the surface of cathode to co-deposite in the electroplating.<br /> The effects of the stirring speed were investigated with various rotational speeds from<br /> 200 to 1000 rpm. Electroplating samples were performed in an electrolyte solution<br /> containing 4 g/L for each kind of CeO2 and CuO at the current density of 2 A/dm2, plating<br /> time for 20 minutes, the temperature of 50 oC. The compositions of CeO2 and CuO<br /> particles in the composite plating layers are shown in Fig. 4.<br /> <br /> <br /> 45<br /> Composition of CeO2 and CuO(%)<br /> <br /> <br /> <br /> <br /> 40<br /> 35<br /> 30<br /> 25<br /> 20<br /> 15<br /> 10<br /> 5<br /> 0<br /> 200 400 600 800 1000<br /> Stirring Speed (rpm)<br /> <br /> Figure 4. Effect of stirring speed on the content of CeO2 and CuO particles<br /> in the plating layers.<br /> From Fig. 4, it can be seen that the agitation of the solution greatly affected the content<br /> of particles in the coating. At the stirring speed of 200 ÷ 400 rpm, the content of CeO2 and<br /> CuO particles in the coating is low. It reachs the maximum of 38.46 % at the stirring speed<br /> of 600 rpm. By increasing the stirring speed from 800 ÷ 1000 rpm, the total content of<br /> CeO2 and CuO particles in the electroplating decreased sharply. This can be explained that<br /> when the stirring speed increases until 800 rpm, the amount of CeO2 and CuO particles<br /> transferred to the cathode more and more. However, when the stirring speed exceeds 800<br /> rpm, the particles transferred to the electrode surface were swept as they are not buried in<br /> the electroplating. Therefore, the content of particles in the coating decreases.<br /> 3.4. The effect of plating time<br /> The conditions for investigating plating time from 5÷30 minutes were as follows:<br /> current density of 2 A/dm2, temperature of 50 oC, stirring speed of 600 rpm and the<br /> concentrations of 4 g/L for each kind of CeO2 and CuO particles.<br /> <br /> <br /> <br /> Tạp chí Nghiên cứu KH&CN quân sự, Số Đặc san CBES2, 04 - 2018 133<br />  Hóa học & Môi trường<br /> <br /> 41<br /> <br /> Composition of CeO2 and CuO ( %)<br /> 36<br /> 31<br /> 26<br /> 21<br /> 16<br /> 11<br /> 6<br /> 1<br /> 0 5 10 15 20 25 30 35<br /> <br /> Time (munite)<br /> Figure 5. Effect of plating time on the composition of CeO2 and CuO particles<br /> in Ni-CeO2-CuO.<br /> The results in Fig. 5 show that the content of CeO2 and CuO particles on the surface of<br /> the plating layers depended insignificantly on plating time. This proves that the plating<br /> process in the solution is stable, so there is no surface passivity during the plating process.<br /> <br /> <br /> <br /> <br /> 5 minutes 20 minutes 35 minutes<br /> Figure 6. SEM images of the surface of samples plated at different plating times.<br /> The SEM images in Fig. 6 indicate that the particles of CeO2 and CuO are relatively<br /> uniformly distributed on the surface of the coating at different plating times. The<br /> distribution of the CeO2 and CuO particles on the surface of the coating does not change<br /> much with changing the plating time from 5 ÷ 35 minutes, so that only 15 minutes should<br /> be enough for plating time.<br /> 4. CONCLUSION<br /> The content of CeO2 and CuO particles in the Ni-CeO2-CuO composite electroplating<br /> coating formed in the nickel-plated solution depended on many factors, among them the<br /> plating time played an insignificant role, therefore, only 15 minutes should be enough for<br /> plating time. It was found the maximum content of CeO2 and CuO particles (38.46%) in<br /> the coating not only at the plating current density of 2 A/dm2 but also by stirring speed of<br /> 600 rpm and the concentrations of CeO2 and CuO particles at 8 g/L in the plating bath<br /> solution.<br /> REFERENCES<br /> [1]. Foster J., Cameron B., "Effect of current density and agitation on the formation of<br /> electrodeposited composite coating", Transactions of the Institute of Metal Finishing,<br /> Vol. 54(4) (1976), pp.178-183[2].<br /> <br /> <br /> <br /> 134 M. V. Phuoc, N. D. Hung, “Some factors affecting on … composite plating coating.”<br /> Nghiên cứu khoa học công nghệ<br /> [2]. Kasturibai S., Paruthimal Kalaignan G., "Characterizations of electrodeposited Ni-<br /> CeO2 nanocomposite coating", Materials Chemistry and Physics, Vol. 147 (2014),<br /> pp. 1042-1048.<br /> [3]. Anna Goral, Marek Nowak, Katarzyna Berent, Bogusz Kania, "Influence of current<br /> density on microstructure and properties of electrodeposited nickel-alumina<br /> composite coating", Journal of Alloys and Compounds, Vol. 615 (2014), pp. 406-410.<br /> [4]. Mai Van Phuoc, Nguyen Duc Hung, "The study on catalytic activity of composite<br /> plating Ni-CeO2-CuO for oxidation", Viet Nam Journal of Catalytic and Adsorption,<br /> Vol. 6(2) (2017), pp. 142-147.<br /> TÓM TẮT<br /> MỘT SỐ YẾU TỐ TRONG QUÁ TRÌNH MẠ ĐIỆN HÓA ẢNH HƯỞNG TỚI<br /> HÀM LƯỢNG HẠT RẮN CeO2 VÀ CuO TRONG LỚP MẠ Ni-CeO2-CuO<br /> Bài báo trình bày một số yếu tố ảnh hưởng đến hàm lượng các hạt CeO2 và CuO<br /> trong lớp mạ tổ hợp Ni-CeO2-CuO được tạo bằng phương pháp mạ điện phân từ<br /> dung dịch mạ niken sunphat. Tổng hàm lượng hạt của CeO2 và CuO trong dung<br /> dịch mạ được thay đổi từ 2 g/L đến 16 g/L, mật độ dòng catot được khảo sát từ 0.5<br /> ÷ 4 A/dm2, tốc độ khuấy trộn dung dịch thay đổi từ 200 vòng/phút đến 1000<br /> vòng/phút, thời gian mạ từ 5 đến 30 phút. Kết quả phân tích EDX thành phần và<br /> chụp ảnh SEM bề mặt lớp mạ cho thấy hàm lượng và sự phân bố hạt trên bề mặt<br /> lớp mạ đạt giá trị lớn nhất bằng 38.46 % tại mật độ dòng điện 2 A/dm2, hàm lượng<br /> CeO2 và CuO trong dung dịch mạ 8 g/L, tốc độ khuấy dung dịch là 600 vòng/phút,<br /> thời gian mạ 15 phút.<br /> Từ khóa: Lớp mạ niken composite; Hạt CeO2; Hạt CuO; Xúc tác CuO/CeO2.<br /> <br /> Nhận bài ngày 16 tháng 02 năm 2018<br /> Hoàn thiện ngày 18 tháng 03 năm 2018<br /> Chấp nhận đăng ngày 02 tháng 04 năm 2018<br /> <br /> Địa chỉ: Institute of Chemistry and Materials.<br /> *<br /> Corresponding author : maivanphuoc_bk@yahoo.com.<br /> <br /> <br /> <br /> <br /> Tạp chí Nghiên cứu KH&CN quân sự, Số Đặc san CBES2, 04 - 2018 135<br />