Optimal metal domain size for photocatalysis with hybrid semiconductor-metal nanorods

Abstract

Semiconductor-metal hybrid nanostructures offer a highly controllable platform for light-induced charge separation, with direct relevance for their implementation in photocatalysis. Advances in the synthesis allow for control over the size, shape and morphology, providing tunability of the optical and electronic properties. A critical determining factor of the photocatalytic cycle is the metal domain characteristics and in particular its size, a subject that lacks deep understanding. Here, using a well-defined model system of cadmium sulfide-gold nanorods, we address the effect of the gold tip size on the photocatalytic function, including the charge transfer dynamics and hydrogen production efficiency. A combination of transient absorption, hydrogen evolution kinetics and theoretical modelling reveal a non-monotonic behaviour with size of the gold tip, leading to an optimal metal domain size for the most efficient photocatalysis. We show that this results from the size-dependent interplay of the metal domain charging, the relative band-alignments, and the resulting kinetics.

Strong exciton-localized plasmon coupling in a-Ge24Se76/AuNP heterostructure

“…The suppression of TA as a function of plasmon wavelength indicates that the charge separation from a-Ge 24 Se 76 to AuNP is directly affected by the size of the AuNP. Our experimental results clearly show that the delocalization of the plasma electrons is most effective when the AuNP SPR wavelength lies near the CB of the chalcogenide layer, as noted by Khon et al 12 and Ben-Shahar et al 29 Such delocalization is not prominent in HS2 and HS3 heterostructures since SPR is far away from the bandgap of a-Ge 24 Se 76 . We have fitted the decay of the TA of the three heterostructures at 807 nm by using Eq.…”

Spectroscopic elucidation of energy transfer in hybrid inorganic–biological organisms for solar-to-chemical production

“…A multiexponential decay unsurprisingly indicates several processes at play in the complex M. thermoacetica-CdS hybrids. Rapid picosecond decays were previously measured with colloidal CdS that featured molecular acceptors with fast e − transfer behavior (24)(25)(26). As hot e − relaxation in Cd-chalcogenide quantum dots occurs in the subpicosecond regime, this process does not likely contribute to the TA kinetics in the measured time scale (27).…”

A Gallium Oxide-Graphene Oxide Hybrid Composite for Enhanced Photocatalytic Reaction

“…These products work via the photo-induced redox reactions of adsorbed materials and/or photo-induced hydrophilic conversion of materials [3,4,5]. The acceleration of the photoreaction occurs on a material’s surface, so the introduction of nano-materials and nano-technologies can significantly enhance catalytic efficiency [6,7,8,9]. Meanwhile, two-dimensional (2D) materials, such as graphene and graphene oxide, have been intensively studied in various areas due to their extraordinary high surface-area to volume ratio [10].…”