Video Experimental Relacionado

Updated: Jan 13, 2026

Expression and Purification of Nuclease-Free Oxygen Scavenger Protocatechuate 3,4-Dioxygenase

Expression and Purification of Nuclease-Free Oxygen Scavenger Protocatechuate 3,4-Dioxygenase

Published on: November 8, 2019

Dirección de la selectividad de la electroquímica pulsada hacia el oxígeno singlete a través de la gestión dinámica

Mengjiao Xie¹, Wentian Zheng^1,2, Yifan Ren²

¹College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.

Angewandte Chemie (International ed. in English)

|January 12, 2026

Abstract:

The electrocatalytic generation of singlet oxygen (¹O₂) from molecular oxygen activation offers a green and selective route for water decontamination. However, its practical application is fundamentally constrained by the sluggish desorption of key ^*OOH intermediates, leading to a pervasive "selectivity-efficiency" trade-off. Herein, we design a pulse excitation electrocatalytic system based on a copper electrode featuring tailored nanotip architecture (Cu-T) that synergistically integrates spatial electric field enhancement with dynamic potential control. Under optimized pulsed operation, the system achieves exceptional ¹O₂ selectivity (>90%) and oxygen conversion efficiency (>73%), significantly outperforming conventional potentiostatic methods. In situ spectroscopic analyses and multiphysics simulations reveal that the pulsed protocol coupling with tip effect promotes O₂ adsorption, stabilizes key ^*OOH intermediates, and facilitates their recombination into ¹O₂, thereby bypassing the rate-limiting ^*OOH desorption step. The system also demonstrates broad applicability across diverse organic pollutants and complex water matrices, alongside robust stability in continuous-flow operation. This work establishes a general spatiotemporal strategy to steer electrocatalytic pathways toward highly selective and energy-efficient O₂ activation.

Palabras clave:

Proceso electrocatalítico Electroquímica pulsada Oxígeno singlete Campo eléctrico mejorado por punta Descontaminación del agua

Más Videos Relacionados

Detection of Nitric Oxide and Superoxide Radical Anion by Electron Paramagnetic Resonance Spectroscopy from Cells using Spin Traps

Detection of Nitric Oxide and Superoxide Radical Anion by Electron Paramagnetic Resonance Spectroscopy from Cells using Spin Traps

Published on: August 18, 2012

Anaerobic Protein Purification and Kinetic Analysis via Oxygen Electrode for Studying DesB Dioxygenase Activity and Inhibition

Anaerobic Protein Purification and Kinetic Analysis via Oxygen Electrode for Studying DesB Dioxygenase Activity and Inhibition

Published on: October 3, 2018

Videos de Conceptos Relacionados

Photochemical Electrocyclic Reactions: Stereochemistry

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation

Thermal and Photochemical Electrocyclic Reactions: Overview

Thermal and Photochemical Electrocyclic Reactions: Overview

Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.

Sharpless Epoxidation

Sharpless Epoxidation

The conversion of allylic alcohols into epoxides using the chiral catalyst was discovered by K. Barry Sharpless and is known as Sharpless epoxidation. The use of a chiral catalyst enables the formation of one enantiomer of the product in excess. This chiral catalyst is mainly a chiral complex of titanium tetraisopropoxide and tartrate ester (specific stereoisomer). The stereoisomer used in the chiral catalyst dictates the formation of the enantiomer of the product. In other words, the use of...

E2 Reaction: Kinetics and Mechanism

E2 Reaction: Kinetics and Mechanism

SN2 substitutions and E2 eliminations of alkyl halides proceed via a concerted pathway. While the nucleophile attacks the alpha carbon in SN2 reactions, it functions as a strong base and abstracts a beta hydrogen in the E2 mechanism. The rate-limiting transition state in E2 elimination reactions is characterized by partially broken carbon–hydrogen and carbon–halogen bonds and a partially formed pi bond between the alpha and beta carbons. The beta hydrogen and halide are eliminated...

Thermal Electrocyclic Reactions: Stereochemistry

Thermal Electrocyclic Reactions: Stereochemistry

The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide

Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.