Morphology, chemical state of nanometric-sized Pt–Cu and Pt–Ag particles, and their photocatalytic activity for mineralization of methanol

Nanometric-sized bimetallic Pt–Cu and Pt–Ag nanoparticles protected with PVP were synthesized using a modified protocol of the alkaline polyol method. The nanoparticles were characterized using a series of experimental methods (TEM, XPS, and XRD) to elucidate their morphology, structure, and chemical state. The Pt–Cu powder consisted of nanoparticles with well-defined spherical morphology and a mean diameter of 2.8 nm. In the case of the Pt–Ag system, the small nanoparticles of around 2 nm showed an interesting tendency to assemble in 1D structure, generally with a filament-like morphology. The Pt–Cu and Pt–Ag nanoparticles supported on TiO₂ showed good and stable activity for methanol mineralization. The formation of hydrogen along with CO₂ as reaction products suggests that the supported bimetallic nanoparticles are promising materials for energy-oriented applications, as well as for photochemical abatement of organic pollutants.