Impact of Methanol Photomediated Surface Defects on Photocatalytic H₂ Production Over Pt/TiO₂

Abstract

Co‐catalysts play a critical role in enhancing the efficiency of inorganic semiconductor photocatalysts; however, synthetic approaches to tailoring co‐catalyst properties are rarely the focus of research efforts. A photomediated route to control the dispersion and oxidation state of a platinum (Pt) co‐catalyst through defect generation in the P25 titania photocatalyst substrate is reported. Titania photoirradiation in the presence of methanol induces long‐lived surface defects which subsequently promote the photodeposition of highly dispersed (2.2 ± 0.8 nm) and heavily reduced Pt nanoparticles on exposure to H2PtCl6. The optimal methanol concentration of 20 vol% produces the highest density of metallic Pt nanoparticles. Photocatalytic activity for water splitting and associated hydrogen (H2) production under UV irradiation mirrors the methanol concentration employed during the P25 photoirradiation pretreatment, and resulting Pt loading, resulting in a common mass‐normalized H2 productivity of 3800 ± 130 mmol gPt−1 h−1. Photomediated surface defects (arising in the presence of a methanol hole scavenger) provide electron traps that regulate subsequent photodeposition of a Pt co‐catalyst over P25, offering a facile route to tune photocatalytic efficiency.

Effect of the Microstructure of the Semiconductor Support on the Photocatalytic Performance of the Pt-PtOx/TiO2 Catalyst System

“…This rendered direct comparison of the catalytic properties of the bare TiO 2 materials impossible in this study. Otherwise, our hydrogen production results are of the same order as those in other works [ 13 , 57 , 58 , 59 ]. As can be seen from Figure 2 , the P25-based samples gave a higher H 2 production rate than the sol–gel-based samples, irrespectively if the Pt co-catalyst was formed by hydrogen reduction or calcination.…”

MOFs‐Derived Fusiform In2O3 Mesoporous Nanorods Anchored with Ultrafine CdZnS Nanoparticles for Boosting Visible‐Light Photocatalytic Hydrogen Evolution

“…[ 6–8 ] Among multitudinous H 2 production strategies, solar‐driven hydrogen generation from water via semiconductor photocatalyst has been deliberated as a potential technology for sustainable hydrogen production. [ 9–15 ] It is known that the core and key of solar‐driven H 2 generation technology are the photocatalysts used in the photocatalytic reactions. Since the first report of solar‐driven H 2 generation over TiO 2 under UV‐light irradiation, a variety of semiconductor photocatalysts have been developed as photocatalysts for photocatalytic H 2 evolution from water.…”

Transformation of Highly Stable Pt Single Sites on Defect Engineered Ceria into Robust Pt Clusters for Vehicle Emission Control

“…In this regard, engineering surface defects on widely used metal oxide supports is both academically interesting and industrially useful. For example, defect-engineered TiO 2 has been reported as an efficient photocatalytic material for various reactions, with the fine-tuned TiO 2 exhibiting enhanced visible light response. , The surface defects on TiO 2 could help disperse and stabilize PGMs and tune the electronic states, thus adjusting their catalytic performance. − This approach has also been widely applied to ZnO, Co 3 O 4 , and Nb 2 O 5 for CO/HCs oxidation reactions. − The surface defects on these metal oxides were found to enhance the interaction between PGMs and supports, to facilitate the adsorption, activation, and transfer of active oxygen, and thus to promote the catalytic oxidation performance.…”