The thickness and roughness of the Ni films increase with the increase in electrolytic currents. XRD patterns showed that Ni films were formed in the crystal phase of Ni corresponding to face-centered cubic structure. Pure Ni films obtained by annealing the films in hydrogen medium were used to prepare NiPt alloys due to galvanic reaction of Pt2+ with Ni2+ in H2PtCl6 solution. The influence of the H2PtCl6 solution concentration on the composition of NiPt alloys were investigated by EDX. The results of analyses showed that NiPt alloy formed by using high solution concentration of H2PtCl6 has high composition of Pt. | Communications in Physics, Vol. 27, No. 3 (2017), pp. 245-254 DOI: PREPARATION OF NiPt ALLOYS BY GALVANIC REPLACEMENT REACTION ON Ni FIMLS FOR DIRECT ETHANOL FUEL CELL PHAM VAN VINH † Faculty of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi, Vietnam † E-mail: vinhpv@ Received 09 August 2017 Accepted for publication 31 August 2017 Published 19 September 2017 Abstract. NiPt alloys were prepared successfully by galvanic replacement reaction on the surface of Ni films. The electrolytic deposition of Ni films was investigated to get the high qualities of Ni films for the galvanic reaction. The influence of the electrolytic currents on the morphology and thickness of Ni films were observed by SEM. The thickness and roughness of the Ni films increase with the increase in electrolytic currents. XRD patterns showed that Ni films were formed in the crystal phase of Ni corresponding to face-centered cubic structure. Pure Ni films obtained by annealing the films in hydrogen medium were used to prepare NiPt alloys due to galvanic reaction of Pt2+ with Ni2+ in H2 PtCl6 solution. The influence of the H2 PtCl6 solution concentration on the composition of NiPt alloys were investigated by EDX. The results of analyses showed that NiPt alloy formed by using high solution concentration of H2 PtCl6 has high composition of Pt. The electrocatalytic activities of both Ni films and NiPt alloys toward ethanol oxidation in KOH medium were carried out by the cyclic voltammetry measurement. Alloyed samples exhibited high electrocatalytic activities due to carbonaceous removal and weakening Pt-COads bond. Keywords: galvanic replacement, NiPt alloy nanoparticles, electrolysis deposition, ethanol oxidation, direct fuel cell. Classification numbers: ; ; ; ; . c 2017 Vietnam Academy of Science and Technology 246 PREPARATION OF NiPt ALLOYS BY GALVANIC REPLACEMENT REACTION ON Ni .
