Nanoporous Pt/TiO₂ nanocomposites with greatly enhanced photocatalytic performance

Abstract

In this work, nanoporous titanium dioxide (TiO 2 ) and Pt/TiO 2 composites were obtained by dealloying melt‐spun Al–Si–Ti and Al–Si–Ti–Pt alloys, respectively. The structures had large specific surface areas, small pore diameters, and large pore volumes. Measurements revealed that nanoporous TiO 2 had a favorable photocatalytic performance in the degradation of methyl orange (MO). For Pt/TiO 2 nanocomposites, approximately 98% of the MO solution degraded in 50 min. It is shown that the significant enhancement of the photocatalytic performance of Pt/TiO 2 is a result of the large specific surface area and the synergistic effect between TiO 2 and metallic Pt, which reduced the bandgap of TiO 2 and expanded the absorption range. Moreover, the Schottky barrier formation at the interfaces of Pt/TiO 2 composites reduced the rate of electron–hole (e–h + ) pair recombination, which contributed to the improvement of the photocatalytic performance.