Fig. 2: Graphical illustrations of co-catalysis in dual-active-center catalysts.
From: Site-designed dual-active-center catalysts for co-catalysis in advanced oxidation processes
a, b ECs act as electron donors to drive co-catalysis between active site A1 and active site A2. c Active site A1 adsorbs ECs while active site A2 generates ROS for co-catalytic ECs degradation. d, e PMS serves as an electron donor, facilitating co-catalysis between active site A1 and active site A2. f In the EF process, active sites A1 and A2 co-catalysis in a 3-electron transfer pathway (O2 to •OH radical). g In photo-Fenton systems, active site A1 generates hole (h+), which cooperates with active site A2 to degrade ECs. h Active site A1 modulates the adsorption and binding energy of oxidants/intermediates at active site A2 in Fenton/Fenton-like systems. The pink spheres represent oxygen atoms, the white spheres represent hydrogen atoms, the yellow spheres represent sulfur atoms, the dark gray elliptical spheres represent pollutants (ECs), the light gray elliptical spheres represent active sites A1 and A2, and the sunlight represents the light for photocatalysis.
