Charge Transport Surmounting Hierarchical Ligand Confinement toward Multifarious Photoredox Catalysis

Abstract

Metal nanoparticles (NPs) have been deemed an imperative sector of nanomaterial for triggering the Schottky-junction-driven electron flow in photoredox catalysis, but they suffer from sluggish charge-transfer kinetics, rendering efficient charge flow difficult. Here, we report the construction of unidirectional charge-transfer channel in a metal/semiconductor heterostructure via a ligand-triggered self-assembly method, by which hierarchically branched ligands (DMAP)capped Pd NPs were controllably attached on the WO 3 nanorods (NRs) scaffold, resulting in the well-defined Pd@ DMAP/WO 3 NRs heterostructures. The pinpointed deposition of Pd@DMAP on the WO 3 NRs endows the Pd@DMAP/ WO 3 NRs heterostructure with conspicuously improved photoactivities for organic pollutant mineralization, as well as the capacities for photocatalytic selective oxidation of aromatic alcohols to aldehydes and photoreduction of chromium ions under the irradiation of simulated sunlight and visible light, far surpassing the applicability of blank WO 3 NRs. This is due to the imperative contribution of Pd@DMAP as efficient electron reservoir in accelerating the unidirectional flow of electrons from Pd@DMAP to WO 3 NRs, overcoming the confinement of spatially hierarchically branched ligand and interface configuration. Moreover, interfacial charge transport efficiency is finely tuned by the interface configuration engineering. The active species in the multifarious photoreactions were unveiled, and a linker-triggered photoredox catalysis mechanism was put forward. It is hoped that our current work would afford new strategies for strategically constructing metal/semiconductor heterostructures for versatile photocatalytic applications.

Probing the Advantageous Photosensitization Effect of Metal Nanoclusters over Plasmonic Metal Nanocrystals in Photoelectrochemical Water Splitting

“…Atomically small metal nanoclusters (NCs) consisting of a precise number of metal atoms capped by thiolate linkers have been deemed as promising photosensitizers that are able to extend the light response region of semiconductors. − Compared with metal nanocrystals (NYs), metal NCs are featured by unique physicochemical properties and structural merits. − However, metal NCs normally suffer from unfavorable photostability owing to high surface energy and gradual depletion of surface ligands under continuous light irradiation, which inevitably triggers in situ transformation of metal NCs to metal NYs. , Nevertheless, everything has two sides, and the instability of metal NCs provides a convenient, simple, and efficacious route to fabricate metal NY-based nanomaterials.…”

Maneuvering Intrinsic Instability of Metal Nanoclusters for Boosted Solar-Powered Hydrogen Production

“…or transition metal dichalcogenides (e.g., WS 2 , MoS 2 , NiS, etc. ). − Besides, cocatalyst adornment requires relatively fussy operation . We wonder whether there exists novel charge mediators that play an analogous role as reduction cocatalysts but with easy operativity.…”

Tuning the photosensitization efficiency of atomically precise metal nanoclusters by super-efficient and exquisite interface modulation

“…Conventional metal nanocrystals (NYs) constitute an imperative sector of nanomaterials for multitudinous catalysis. [1][2][3][4][5][6][7][8][9] When the size of metal NYs is reduced to be atomically small (<2 nm) with a precise number of metal atoms and surface ligands, they are referred to as "metal nanoclusters (NCs)" having physicochemical properties distinct from those of metal NY counterparts, which are featured by a molecule-like discrete energy band structure. [10][11][12][13][14][15] The favorable highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap renders the metal NCs emerging light-harvesting photosensitizers for photoredox catalysis.…”