Interfacial Modulation with Aluminum Oxide for Efficient Plasmon‐Induced Water Oxidation

Abstract

Plasmon‐induced photocatalysts hold great promise for solar energy conversion owing to their strong light‐harvesting ability and tunable optical properties. However, the complex process of interfacial extraction of hot carriers and the roles of metal/semiconductor interfaces in plasmonic photocatalysts are still not clearly understood. Herein, the manipulation of the interface between a plasmon metal (Au) and a semiconductor (rutile TiO2) by introducing an interfacial metal oxide (Al2O3) is reported. The resulting Au/Al2O3/TiO2 exhibits remarkable enhancement in photocatalytic water oxidation activity compared with Au/TiO2, giving an apparent quantum efficiency exceeding 1.3% at 520 nm for photocatalytic water oxidation. Such an interfacial modulation approach significantly prolongs the lifetime of hot carriers in the Au/TiO2 system, which conclusively improves the utilization of hot carriers for plasmon‐induced water oxidation reaction upon irradiation. This work emphasizes the essential role of the interfacial structure in plasmonic devices and provides an alternative method for designing efficient plasmonic photocatalysts for solar energy conversion.

Achieving selective photocatalytic CO2 reduction to CO on bismuth tantalum oxyhalogen nanoplates

“…S15 †). 24 In addition, the ne spectrum of Ag showed the coexistence of peaks at 373.8 and 367.8 eV, which is due to spinorbit splitting according to the literature, indicating the presence of the metallic state of Ag 0 , which agrees well with the HRTEM analysis. 25,26 The Ag nanoparticles on the surface show some aggregation aer the cycling reaction, and the structural characterizations of Ag-Bi 4 TaO 8 Br-F aer the photocatalytic reactions indicate that it maintained similar phase and chemical states on the surface to the fresh material (Fig.…”

Recent advances and perspectives for solar-driven water splitting using particulate photocatalysts

“…168 It was reported that the modulation of Al 2 O 3 at the interface between Au and TiO 2 can greatly prolong the lifetime of hot carriers and promote the spatial separation of hot carriers, as depicted by ultrafast time-resolved spectra and steady-state surface photovoltage (SPV) spectra. 169 Defects at the interface may act as recombination centers for electrons with holes at the interface, thus influencing the charge utilization in SPR-induced photocatalysts. 170 Strategies including the construction of heterojunctions, 171 employing spatial charge separation between facets, 172 ferroelectric effects, 156 and modulation of metal nanostructures including surface ligands 173,174 have also been applied to obtain plasmonic carriers with longer lifetimes and promote charge separation in LSPR-induced photocatalysts.…”

Recent Advances in Noncontact External-Field-Assisted Photocatalysis: From Fundamentals to Applications

“…Recently, Zeng et al introduced an atomic layer of inert Al 2 O 3 between the plasmonic metal Au and semiconductor TiO 2 . 78 This new interface structure improved the utilization of hot carriers for plasmon-induced water oxidation under irradiation and achieved a quantum efficiency of 1.3% for photocatalytic water oxidation at 520 nm. In order to further explore the role of Al 2 O 3 in the interfacial charge separation, the researchers also used ultrafast time-resolved spectroscopy and surface photovoltage spectra to characterize the charge separation and migration process.…”

“…Although excellent photocatalytic activity can be obtained by this method, the preparation of the materials is more complex, which is not conducive to its popularization and application. Recently, Zeng et al introduced an atomic layer of inert Al 2 O 3 between the plasmonic metal Au and semiconductor TiO 2 . This new interface structure improved the utilization of hot carriers for plasmon-induced water oxidation under irradiation and achieved a quantum efficiency of 1.3% for photocatalytic water oxidation at 520 nm.…”

“…(b) Ultrafast time-resolved spectra and surface photovoltage spectra of Au/TiO 2 and Au/Al 2 O 3 /TiO 2 . Reprinted with permission from ref . Copyright 2020 Wiley-VCH.…”