Open AccessImpact of Methanol Photomediated Surface Defects on Photocatalytic H 2 Production Over Pt/TiO 2
Author(s) -
Jiang Zhi,
Qi Rongjie,
Huang Zhengwen,
Shangguan Wenfeng,
Wong Roong Jien,
Lee Adam
Publication year - 2020
Publication title -
energy and environmental materials
Language(s) - English
Resource type - Journals
ISSN - 2575-0356
DOI - 10.1002/eem2.12068
Subject(s) - photocatalysis , catalysis , methanol , materials science , hydrogen production , platinum , chemical engineering , nanoparticle , substrate (aquarium) , metal , dispersion (optics) , nanotechnology , photochemistry , chemistry , metallurgy , organic chemistry , optics , engineering , oceanography , physics , geology
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 H 2 PtCl 6 . The optimal methanol concentration of 20 vol% produces the highest density of metallic Pt nanoparticles. Photocatalytic activity for water splitting and associated hydrogen (H 2 ) production under UV irradiation mirrors the methanol concentration employed during the P25 photoirradiation pretreatment, and resulting Pt loading, resulting in a common mass‐normalized H 2 productivity of 3800 ± 130 mmol g Pt −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.