2025/05/27 by Asier Agrelo‐Lestón, Lluís Soler, Jordi Llorca · 1 voice
Energy · Materials Science · #Advanced Photocatalysis Techniques #TiO2 Photocatalysis and Solar Cells #Electronic and Structural Properties of Oxides
paper · pdf · doi:10.1002/cctc.202500538
openalex publication_date 2025/05/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Abstract A series of Pt‐decorated TiO 2 photocatalysts was synthesized via mechanochemical methods, varying Pt precursors (K 2 PtCl 6 , H 2 PtCl 6 , PtO 2 , Pt(NH 3 ) 4 (NO 3 ) 2 , Pt(acac) 2 , and PtCl 2 ), Pt loadings, and milling conditions (time, energy, and ball‐to‐powder ratio). Hydrogen photoproduction was evaluated under dynamic conditions using gas‐phase ethanol–water mixtures and UV light. The optimal catalyst, prepared with K 2 PtCl 6 at 0.33 wt.% Pt, exhibited the highest hydrogen production rate (7.4 mmol H 2 h −1 g cat −1 ). Synthesis optimization via a Taguchi design of experiments identified low milling time, energy, and ball‐to‐powder ratio as key factors. Compared to a conventional Pt/TiO 2 catalyst prepared by incipient wetness impregnation, the best ball‐milled sample showed 1.3 times higher hydrogen production and 1.2 times faster stabilization. Advanced characterization (HAADF‐STEM) revealed isolated Pt atoms in the ball‐milled catalyst, in contrast to small clusters in the reference. Post‐reaction analysis showed nanoparticle growth in both samples, but only the conventional sample developed fully formed nanoparticles (2.0 ± 0.8 nm). XPS detected a significant increase in surface K in the conventional catalyst due to a resurfacing effect. The superior performance of the ball‐milled sample is attributed to the stabilization of Pt single atoms and suppression of surface K restructuring, enhancing charge separation via modulation of the Schottky barrier.