近日，中国科学院化学研究所白书明团队报道了通过三重态电荷复合和磁场效应协同增强单重态瓶颈之外的光还原催化。该项研究成果发表在2025年11月11日出版的《德国应用化学》杂志上。

有机光敏剂的氧化还原活性激发态已推动了光氧化还原催化的发展，但其效率常受自发反向电子转移（BET）的限制，尤其在单重态驱动的路径中。因此，提升三重态利用率对改善催化性能至关重要，但实现这一目标颇具挑战，尤其在不改变催化剂结构的情况下。

研究组以吩噻嗪型光敏剂为模型体系，提出了一种协同策略，使反应效率提升近300%。结果显示，在非极性胶束核心中，三重态电荷重组（TCR）显著增强，促进三重态生成并高效促进三重态与底物的相互作用。此外，沿三重态路径引入外部磁场可抑制自由基离子对中间体的自旋转换（从三重态到单重态），从而降低BET。所开发的激发动态模型为磁场效应提供了定量分析和机制验证。该工作建立了一种强有力的协同策略来调控光氧化还原机制，为提升催化性能提供了新框架。

附：英文原文

Title: Synergistic Enhancement of Photoredox Catalysis Beyond the Singlet Bottleneck Through Triplet Charge Recombination and Magnetic Field Effects

Author: Mingli Sun, Chenli Chen, Lingfang Chen, Jiayi Liang, Jie Cheng, Jialu Li, Shuming Bai, Jialong Jie, Hongmei Su, Song Gao, Linan Zhou

Issue&Volume: 2025-11-11

Abstract: Organic photosensitizers with redox-active excited states have revitalized photoredox catalysis, but their efficiency is often hindered by spontaneous back electron transfer (BET), particularly in singlet-driven pathways. Enhancing triplet utilization is therefore critical for improving catalytic performance but remains challenging, especially without structural modifications to the catalyst. Here, using phenothiazine-type photosensitizers as a model system, we demonstrate a synergistic strategy that enhances reaction efficiency by almost 300%. Triplet charge recombination (TCR) is shown to be significantly promoted within the nonpolar micellar core, enhancing triplet generation and facilitating efficient triplet-substrate interactions. Furthermore, an external magnetic field is introduced along the triplet pathway to depress BET by inhibiting spin conversion of radical-ion-pair intermediates from triplet to singlet. The developed kinetic modeling provides quantitative insights and mechanistic validation of the magnetic field effect. This work establishes a powerful synergistic strategy to control photoredox mechanisms, offering a new framework for advancing catalytic performance.

DOI: 10.1002/anie.202518648

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202518648