Mechanistic Illustration of the facet modulated Ru(bpy)32+ cathodic/anodic ECL system. O2 molecules undergo ORR at the cathode, while H2O molecules undergo OER at the anode on different catalyst facets. Ni/NG-1 exhibits high OER but low ORR activity, generating radicals that react with Ru(bpy)32+ to enhance cathodic ECL. In contrast, Ni/NG-2 shows high ORR but low OER activity, thus promoting anodic ECL through a similar radical-assisted pathway.
Abstract:
Reactive oxygen species (ROS) have gained increasing attention in electrochemiluminescence (ECL) as endogenous co-reactants, yet their application in the most widely used tris(bipyridine)-ruthenium(II) system remains limited due to the scarcity of suitable co-reactant accelerators (CRAs) with selective oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalytic activity. Here, this work reports a series of facet-tunable homogeneous NiNPs catalysts, which can stimulate ECL at distinguishable cathodic/anodic potentials in tris(bipyridine)-ruthenium(II) system. Experimental studies and theoretical calculation results reveal that the Ni(1 1 0) surface, with its lower charge density, impedes the fourth step of 4e− ORR, thus favoring 2e− pathway and consequently promoting substantial ROS generation and ECL at the cathode. Conversely, the Ni(1 1 1) and (2 0 0) surface prompt robust and stable anodic ECL via hydroxyl radical by controlling the OER. These excellent CRAs link cathodic/anodic ECL with ORR/OER, offering a novel strategy for precisely designing predictable non-precious metal CRAs. Furthermore, sensitive immunosensors were developed using these CRAs, demonstrating successful application in potential-resolved ECL analysis for practical purposes.
Author list:
Zixin Deng†, Zhizhi Xiang†, Shu Zhu†, Yuchan Zhang†*, Yu Du, Shijun Wang, Ziqi Kang, Zixu Wang, Xuehao Tong, Yangkun Liu, Lingfang Jiang, Anna Malashicheva, Hao Sun, Feng Dong*, Guixue Wang*, Chenzhong Li*, Guangchao Zang*
How to cite:
Z. Deng, Z. Xiang, S. Zhu, Y. Zhang, Y. Du, S. Wang, Z. Kang, Z. Wang, X. Tong, Y. Liu, L. Jiang, A. Malashicheva, H. Sun, F. Dong, G. Wang, C. Li, G. Zang, Exploration 2025, 5, 20250036.
https://doi.org/10.1002/EXP.20250036