Highly isolated Pt NPs embedded in porous TiO2 derived from MIL-125 with enhanced photocatalytic hydrogen production activity

Pt/TiO2, with traditional surface-loaded cocatalyst Pt, not only suffers from Pt aggregation, but also the problem of cocatalyst losing during photocatalytic reactions. Here, porous TiO2 with embedded Pt (Pt@TiO2) was successfully prepared via in situ hydrothermal reaction followed by calcination using Pt@MIL-125 as precursor. The characterizations showed that Pt nanoparticles (NPs) were highly isolated inside of TiO2. The porous structure of TiO2 can provide abundant pathways for the mass transfer. Photocatalytic hydrogen production reactions showed that Pt@TiO2 reached to an activity of 4.389 mmol/h/g with the apparent quantum efficiency of 39% at 380 nm, which was 6.4 times that for Pt/TiO2. Besides, Pt@TiO2 could efficiently prevent Pt NPs from losing and exhibited a good stability compared with Pt/TiO2. Dynamic characterizations indicated that the embedded Pt@TiO2 not only provides more active sites of Pt, but also facilitate the charge utilization, which contribute to the excellent photocatalytic activity. (C) 2021 Elsevier Inc. All rights reserved.