Interparticle Charge‐Transport‐Enhanced Electrochemiluminescence of Quantum‐Dot Aerogels

Abstract

Electrochemiluminescence (ECL) represents a widely explored technique to generate light, in which the emission intensity relies critically on the charge‐transfer reactions between electrogenerated radicals. Two types of charge‐transfer mechanisms have been postulated for ECL generation, but the manipulation and effective probing of these routes remain a fundamental challenge. Here, we demonstrate the design of quantum dot (QD) aerogels as novel ECL luminophores via a versatile water‐induced gelation strategy. The strong electronic coupling between adjacent QDs enables efficient charge transport within the aerogel network, leading to the generation of highly efficient ECL based on the selectively improved interparticle charge‐transfer route. This mechanism is further verified by designing CdSe‐CdTe mixed QD aerogels, where the two mechanistic routes are clearly decoupled for ECL generation. We anticipate our work will advance the fundamental understanding of ECL and prove useful for designing next‐generation QD‐based devices.

Electrochemiluminescence Mechanistic Insights of CuInS2/ZnS Nanocrystals with Hydrazine Compounds as Co-reactants

“…DPV is a powerful technology to explore the valence band (VB) hole injection process of oxidized CIS/ZnS NCs or the CB electron injection process of reduced CIS/ZnS NCs under differed electrolyte conditions . According to Figure , CIS/ZnS NCs primarily exhibit two oxidative processes at around ∼0.4–0.5 and ∼0.8–1.0 V when the electrolyte is acidic.…”

“…DPV is a powerful technology to explore the valence band (VB) hole injection process of oxidized CIS/ZnS NCs or the CB electron injection process of reduced CIS/ZnS NCs under differed electrolyte conditions. 34 According to Figure 3, CIS/ZnS NCs primarily exhibit two oxidative processes at around ∼0.4−0.5 and ∼0.8−1.0 V when the electrolyte is acidic. It was reported that CIS/ZnS NCs/N 2 H 4 • H 2 O system could also produce two ECL processes around 0.46 and 0.87 V under physiological conditions, which was consistent with the DPV results in this case.…”

Energy Level Engineering in Gold Nanoclusters for Exceptionally Bright NIR Electrochemiluminescence at a Low Trigger Potential

“…Thus, electron transfer reactions between emitters and the coreactants are critical to regulate the excitation efficiency and ECL trigger potential in coreactant-pathway ECL systems. 6−8 To date, various strategies have been developed to improve the above reactions, such as interparticle charge tansport, 8 electrocatalysis, 6,9 and intrareticular charge transfer-mediated competitive oxidation. 10 Nevertheless, most discussion was only at the phenomenological level, while a deeper intrinsic mechanism for ECL generation has yet to be elucidated.…”

“…Among them, electrochemiluminescence (ECL), a widely used light radiation energy output converted from electrochemical excitation, has evoked increasing interest for decades and becomes a powerful tool with precise temporal and spatial controllability, near-zero backgrounds, and a wide dynamic range. − ECL relies on electron transfer reactions between the electrochemically generated highly reactive radical intermediates on an electrode surface. Thus, electron transfer reactions between emitters and the coreactants are critical to regulate the excitation efficiency and ECL trigger potential in coreactant-pathway ECL systems. − To date, various strategies have been developed to improve the above reactions, such as interparticle charge tansport, electrocatalysis, , and intrareticular charge transfer-mediated competitive oxidation . Nevertheless, most discussion was only at the phenomenological level, while a deeper intrinsic mechanism for ECL generation has yet to be elucidated.…”

Bimetallic Pd–Co Aerogel Three-Dimensional Architecture: Developing Self-Assembled Materials for Advanced Ethanol Oxidation

“…In this context, noble metal aerogels (NMAs) have attracted an extensive contribution of scientific projects because of their unbelieved morphology. These extraordinary NAs not only represent the 3D macrostructures with a very low density but also offer porous networks with abundant tunnels. − Additionally, they reflect two unique characteristics for application in electrocatalysis-related processes: − (1) The reactants can contact easily with the surface and inner active sites of NMAs because of their macroscopic character. (2) The durability relevant to a compound plays a pivotal role in commercializing catalysts.…”