Quantum Dot Assembly for Light‐Driven Multielectron Redox Reactions, such as Hydrogen Evolution and CO₂ Reduction

Abstract

Light‐driven multielectron redox reactions (e.g., hydrogen (H2) evolution, CO2 reduction) have recently appeared at the front of solar‐to‐fuel conversion. In this Minireview, we focus on the recent advances in establishing semiconductor quantum dot (QD) assemblies to enhance the efficiencies of these light‐driven multielectron reduction reactions. Four models of QD assembly are established to promote the sluggish kinetics of multielectron transfer from QDs to cocatalysts, thus leading to an enhanced activity of solar H2 evolution or CO2 reduction. We also forecast the potential applications of QD assemblies in other multielectron redox reactions, such as nitrogen (N2) fixation and oxygen (O2) evolution from H2O.

Transition Metal Chalcogenides Quantum Dots: Emerging Building Blocks toward Solar-to-Hydrogen Conversion

“…One attractive photocatalytic system should contain TMCs QDs as the PS in place of traditional organic dyes and noble-metal-free complex as the Cat for solar-to-fuel conversion. To make water-soluble QDs, an ultrathin organic ligand layer with an anchoring headgroup tethered to QDs and a hydrophilic tail directed away from the inorganic core, is capped on the QDs surface (Figure b). , The charge transfer from QDs (electron donor) to Cat (electron acceptor) is diffusion-controlled, by which mutual electron delivery is random or indirect (Figure d). However, Li et al found that QDs’ surface defects could be produced as a result of partial loss of surface-capping ligands upon transferring to aqueous solutions.…”

Transition metal quantum dots for the electrocatalytic hydrogen evolution reaction: recent progresses and challenges

“…55,56 Amongst all of these materials, the transition metal quantum dots which have enhanced properties like increased surface area, higher surface to volume ratio, fluorescent properties, conductivity and so on together contributing to an exemplary activity of these materials in electrochemical hydrogen evolution reaction. [57][58][59] Fig. 3(a-b) The "volcano" plot by Trasatti 33 from experimental and the "volcano" plot derived from DFT by Norskov et al 34 Reproduced from ref.…”

“…55,56 Amongst all of these materials, the transition metal quantum dots have enhanced properties such as increased surface area, a higher surface-to-volume ratio, fluorescence properties, and conductivity, together contributing to an exemplary activity of these materials in the electrochemical hydrogen evolution reaction. 57–59…”

“…55,56 Amongst all of these materials, the transition metal quantum dots have enhanced properties such as increased surface area, a higher surface-tovolume ratio, fluorescence properties, and conductivity, together contributing to an exemplary activity of these materials in the electrochemical hydrogen evolution reaction. [57][58][59] 3.1. Transition metal quantum dots: synthesis and their application in HER Quantum dots (QDs), in general, nano-sized semiconductor crystals, have found fascinating applications in numerous scientific fields.…”