Crystallographic interface control of the plasmonic photocatalyst consisting of gold nanoparticles and titanium(iv) oxide. Issue 42 (25th October 2022)

• Record Type: Journal Article
• Authors: Naya, Shin-ichi; Akita, Atsunobu; Morita, Yoko; Fujishima, Musashi; Tada, Hiroaki
• Is Part Of: Chemical science. Volume 13:Issue 42(2022)
• Page Start: 12340
• Page End: 12347
• Publication Date: 2022-10-25
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d2sc03549a
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : In the represented plasmonic photocatalyst consisting of Au nanoparticles (NPs) and TiO2, the combination of crystal facet engineering of TiO2 and atom-level-interface control between Au NP and TiO2 gives rise to a drastic activity enhancement. Abstract : A big question in the field of plasmonic photocatalysis is why a typical photocatalyst consisting of gold nanoparticles and rutile titanium(iv ) oxide (Au/R-TiO2 ) usually exhibits activity much higher than that of Au/anatase TiO2 (Au/A-TiO2 ) under visible-light irradiation. Shedding light on the origin should present important guidelines for the material design of plasmonic photocatalysts. Au nanoparticles (NPs) were loaded on ordinary irregular-shaped TiO2 particles by the conventional deposition precipitation method. Transmission electron microscopy analyses for the Au/TiO2 particles ascertain that faceting of Au NPs is induced on R-TiO2 by using a domain-matching epitaxial junction with the orientation of (111)Au //(110)R-TiO2, whereas non-faceted hemispherical Au NPs are exclusively formed on A-TiO2 . The faceting probability of Au NPs ( P f ) on R-TiO2 increases with decreasing Au particle size ( d Au ) to reach 14% at d Au = 3.6 nm. A clear positive correlation between the photocatalytic activity and P f in several test reactions indicates that the heteroepitaxial junction-induced faceting of Au NPs is the principal factor for governing the plasmonic photocatalytic activity of Au/TiO2 . In light of this finding, R-TiO2 nanorods with a high percentage (95%) of {110} facets were hydrothermally synthesized and used for the support of Au NPs. Consequently, the P f value increases to as much as 94% to enhance the photocatalytic activity with respect to that of Au/R-TiO2 with P f = 14% by factors of 2.2–4.4 depending on the type of reaction.