Platinum nanoparticles confined within TiO2 nanotube matrix for enhanced catalytic reduction of azure b dye

Abstract

• PtNPs confined TiO 2 nanotubes were successfully obtained. • HR-TEM analysis confirmed that the PtNPs (particle size ∼ 2–3 nm) were inside of the TiO 2 NTs. • The PtNPs-TiO 2 NTs were highly efficient for the catalytic reduction of AZB dye. • The PtNPs-TiO 2 NTs catalyst was active over 8 recycles. In this work, we report the synthesis of TiO 2 nanotubes encapsulated platinum nanoparticles (PtNPs-TiO 2 NTs) as a highly efficient catalyst for the catalytic reduction of azure B (AZB) dye in the sodium borohydride (NaBH 4 ) medium. The encapsulation of PtNPs (particle size ∼ 2–3 nm) inside the TiO 2 NTs was confirmed by HR-TEM analysis. The as-prepared PtNPs-TiO 2 NTs exhibit higher conversion efficiency than 99 % with a pseudo-first order rate constant of 2.6 × 10 -3 s −1 . Owing to the confinement effect of PtNPs inside the TiO 2 NTs, the synthesized catalyst shows the superior operative stability even after 8 consecutive recycles without any loss in its activity. This work opens up new avenue for the designing of confined catalyst for various industrial catalytic reactions.