A facile preparation of highly dispersed ultrasmall CeO2 clusters on g-C3N4 decorated TiO2 for efficient photooxidation of Hg0

Elemental mercury (Hg 0 ) is the most difficult mercury species to remove from the flue gas. Photocatalysts of transition metal oxide modified TiO 2 can effectively remove Hg 0 . However, the metal oxide easily aggregates into large nanoparticles, reducing the atom utilization efficiency and photocatalytic activity. We presented a facile strategy of employing g-C 3 N 4 as an anchor to successfully load highly dispersed ultrasmall CeO 2 clusters on g-C 3 N 4 /TiO 2 . Moreover, the mechanism of anchoring CeO 2 clusters and charge transfer of the ternary photocatalyst were explored in-depth. The results demonstrated that at 250 °C, the photooxidation efficiency of Hg 0 by CeO 2 -g-C 3 N 4 /TiO 2 was several times higher than that of CeO 2 /TiO 2 , TiO 2 , and g-C 3 N 4 . The cavity of the tri-s-triazine ring anchored small CeO 2 clusters via strong Ce-N coordination bonds. A combined type II and Z-scheme transport paths accelerated the separation of photogenerated electron holes. This research offers valuable surface engineering strategy for highly dispersed ultrasmall cluster decorated TiO 2 .