Evolution of CoNi Alloy Electronic Structure Buffered by Carbon Nanolayer to Tune Selective Generation of Reactive Oxygen Species.

Generation of non-radical reactive oxygen species (ROS) via peroxymonosulfate (PMS) activation is desired to drive selective Fenton-like reactions and strongly affected by the electronic structure of catalyst. While the static structure-activity relationship of catalysts is well explored, how the evolution of electronic structure dynamically affects the ROS generation remains poorly understood. This study fabricated carbon nanolayer-supported CoNi alloys (CoNi@CNT) with preset atomic Ni/Co ratio (x/y = 1:3, 2:2, 3:1) to probe the dynamic evolution of electronic structure and its subsequent role for the generation of non-radical ROS. During catalytic PMS activation, the paired electrons of O 2p in PMS fill the corresponding hybrid orbitals of Co to form coordinative Co-O endowed with paired/unpaired electrons. The carbon nanolayer support, as in situ formed with controllable lattice distance, exhibits the unique electron buffering effect to replenish electron to CoNi or accept electron from CoNi, thereby driving selective generation of surface PMS* or free O respectively. Further, the specific reaction preferences of PMS and O toward different organic contaminants were elucidated, and a combined process integrating both alloys was proposed to efficiently treat actual hospital wastewater. Overall, this study offers a molecule-level design of bimetallic alloys with tunable electronic structure for sustainable water purification.