Spiky TiO₂/Au nanorod plasmonic photocatalysts with enhanced visible-light photocatalytic activity

Abstract

A facile approach for the preparation of spiky TiO/Au nanorod (NR) plasmonic photocatalysts has been demonstrated, which is through in situ nucleation and growth of spiky TiO onto AuNRs. Different aspect ratios of AuNRs in 2.5, 2.7, 4.1 and 4.5 have been applied to prepare spiky TiO/AuNR nanohybrids to achieve tunable and broad localized surface plasmon resonance (LSPR) bands. All spiky TiO/AuNR nanohybrids exhibit enhanced light harvesting by extending visible light absorption range by both transverse and longitudinal LSPR bands and decreasing light reflectance by their unique spiky structures. Compared to the bare AuNRs, commercial TiO (P25) and spiky TiO/Au nanosphere photocatalysts, the spiky TiO/AuNR photocatalysts exhibit significantly enhanced visible light photocatalytic activity in Rhodamine B (RhB) degradation due to their simultaneous enhancement in the light harvesting, charge utilization efficiency, and substrate accessibility. In particular, the spiky TiO/AuNR-685 photocatalysts show the best photocatalytic activity with ∼98.9% of the RhB degraded within 90 min under the irradiation of 420-780 nm, which could be ascribed to the most extended visible light absorption range and sufficient photon energy of TiO/AuNR-685 photocatalysts within this irradiation region. The bio-inspired nanostructure, as well as the facile and scalable fabrication approach, will open a new avenue for the rational design and preparation of high-performance photocatalysts for pollutant removal and water splitting.

Light‐Driven Sustainable Hydrogen Production Utilizing TiO2 Nanostructures: A Review

“…We emphasize the state‐of‐the‐art routes for the construction of 0D–3D TiO 2 with various nanostructures for H 2 generation. Nevertheless, two dominant defects (inferior absorption performance in visible light and recombination of photogenerated e − –h + pairs) still impede the development of TiO 2 . To deal with aforementioned obstacles, numerous strategies have been attempted, containing enlarging the accessible surface active areas, doping engineering, crystallinity optimizing, heterocoupling with narrow bandgap semiconductors are discussed .…”

Gold nanorods-conjugated TiO2 nanoclusters for the synergistic combination of phototherapeutic treatments of cancer cells

“…On the other hand, the NIR irradiation causes LSPR excitation of Au NRs are known to form hot electrons which are injected into the conduction band (CB) of the conjugated TiO 2 NPs with photogenerated holes left in Au NRs [48, 49]. Such an interfacial electron transfer from Au to TiO 2 in the nanocomplex would be further facilitated by overcoming Schottky barrier through the NIR-induced heat generation from the Au NRs as reported in other Au–TiO 2 nanohybrids which are applied to visible light photocatalysts for the destruction of pollutants [50–53]. Consequently, more · O 2 − can be produced by the reaction of oxygen molecules with the injected electrons in the CB of TiO 2 NPs through the LSPR excitation.…”

Challenges and Prospects in Solar Water Splitting and CO2 Reduction with Inorganic and Hybrid Nanostructures

“…In general, there are three different ways to use plasmonic NPs for the benefit of photocatalytic reactions: ,,, (1) direct, hot electron-induced photocatalysis on plasmonic NP surface (Figure a), (2) hot-electron transfer from plasmonic NP to nearby semiconductor or metal (Figure b), − (3) SPR-induced electromagnetic field enhancement (Figure c) . These three approaches have been under extensive investigation in recent years for plasmon-enhanced enhanced photocatalytic as well as photoelectrochemical water splitting, CO 2 reduction and other chemical reactions.…”