One-step synthesis of PtNi anchored on TiO2 nanotube arrays for methanol oxidation

Highly active, stable, economic friendly electrocatalysts play a crucial role for the commercialization of direct methanol fuel cells (DMFCs). One kind of flower-like PtNi bimetallic particle anchored on TiO2 nanotube arrays (PtNi/TNTs/Ti) had been synthesized by one-step electrochemical synthesis as anode catalysts for methanol oxidation reaction (MOR) in this study. The PtNi/TNTs/Ti electrode demonstrated high electrocatalytic activity and durability significantly for MOR. In addition, PtNi100/TNTs/Ti possessed a mass activity of 409.8 mA/mgpt, which was four times greater than that of Pt100/TNTs/Ti electrodes. According to further structure analysis, the improvement in catalytic activity was attributed to lattice compression when Ni atoms entered the Pt lattice accompanied by a 1.02 eV positive shift in Pt 4 f7/2 binding energy, and density functional theory (DFT) calculations indicated that the remarkably enhanced catalytic performance on PtNi through lattice compression arising from the enhanced OH adsorption. It appears promising that this simple method could be adopted to prepare an integrated electrode used as energy and environmental applications. •Preparation of PtNi anchored on TiO2 nanotube arrays by one-step electrochemical deposition.•PtNi bimetallic catalysts caused the lattice compressive strain due to Ni atoms.•The enhanced OH adsorption could be the origin of the improved catalytic activity confirmed by theoretical calculations.