Plasmon-Mediated Oxidase-like Activity on Ag@ZnS Heterostructured Hollow Nanowires for Rapid Visual Detection of Nitrite

Abstract

Rational design of fast and sensitive determination of nitrite (NO2 –) from a complicated actual sample overtakes a crucial role in constructing a high-efficiency sensing platform. Herein, a visual NO2 – sensing platform with outstanding selectivity, sensitivity, and stability based on a surface plasmon resonance (SPR)-enhanced oxidase-like activity has been proposed. Benefiting from the intrinsic photocatalytic activity and limited light penetration of ZnS, the oxidase-like activity based on ZnS decorated on Ag nanowires (Ag@ZnS) is determined. It is demonstrated that the electrons are generated efficiently on the surface of ZnS and then transferred into the hot electrons of Ag with the help of localized SPR excitation, thus greatly oxidating the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to produce dark blue oxidized TMB (oxTMB). When nitrite is added into the reaction system, the oxTMB will selectively react with NO2 – to generate diazotized oxTMB, leading to a visual color change from dark blue to light green and subsequently to dark yellow. Owing to the specific recognition between nitrite and oxTMB, the recovery of catalytic activity induced an enhanced colorimetric test with a wider linear range for NO2 – determination, an ultralow detection limit of 0.1 μM, excellent selectivity, and practicability for application in real samples. This plasmon-enhanced oxidase-like activity not only provides a smart approach to realize a colorimetric assay with high sensitivity and simplicity but also modulates oxidase-like activities.

Dual-cation doping precisely reducing the energy barrier of the rate-determining step for promoting oxygen-evolving activity

“…According to the OER mechanism, it is well known that OER involves the generation of intermediates of M-OH*, M-O*, and MOOH*, where the rate-determining step (RDS) in the OER process plays a crucial role in determining the catalytic efficiency of nanocatalysts. [28][29][30] Thereupon, it is fundamentally and practically meaningful to understand and tailor the energy barrier of RDS. Recent studies suggest that electronic structure engineering is highly effective for modifying the electronic properties of OER catalysts to afford moderated binding strength between active sites and intermediates, 31,32 thereby leading to a significantly decreased energy barrier of the OER process.…”

Strategies for Promoting Catalytic Performance of Ru‐Based Electrocatalysts towards Oxygen/Hydrogen Evolution Reaction

“…Although intensive endeavors have been dedicated to the development of more efficient electrocatalysts to overcome the energy barrier and accelerate reaction kinetics of OER and HER, the practical applications of these electrocatalysts are still unavailable due to the limited catalytic activity and poor stability. [21][22][23] Generally, precious metal platinum (Pt) is widely considered as the "Holy Grail" for HER, displays outstanding electrocatalytic activity and durability. [24,25] However, the high price has been a major obstacle hindering the industrial implementation.…”

“…Aiming to reduce the potential and electrical energy for water splitting, enormous efforts have been dedicated to the rational design and fabrication of advanced electrocatalysts for HER and OER. Although intensive endeavors have been dedicated to the development of more efficient electrocatalysts to overcome the energy barrier and accelerate reaction kinetics of OER and HER, the practical applications of these electrocatalysts are still unavailable due to the limited catalytic activity and poor stability [21–23] …”

Interfacial built-in electric-field for boosting energy conversion electrocatalysis

“…For example, constructing a metal-support interface is widely considered as a promising approach to achieve high catalytic performance, in which the metal can adsorb hydrogen and the support can promote the water dissociation and function as the real active sites to adsorb the hydroxide intermediates. 24,25 However, the overlap of the electron cloud across the interface will drive the charge carriers to experience severe localization, resulting in limited electron transfer and poor catalytic performance. In recent years, creating an interfacial BIEF in a heterojunction will effectively relieve the electron cloud localization and induce the interfacial space charge and band bending to separate electrons and protons, thereby effectively altering the charge distribution and affecting the intermediate adsorption.…”