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 TiO2 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-C3N4 as an anchor to successfully load highly dispersed ultrasmall CeO2 clusters on g-C3N4/TiO2. Moreover, the mechanism of anchoring CeO2 clusters and charge transfer of the ternary photocatalyst were explored in-depth. The results demonstrated that at 250 degrees C, the photooxidation efficiency of Hg-0 by CeO2-g-C3N4/TiO2 was several times higher than that of CeO2/TiO2, TiO2, and g-C3N4. The cavity of the tri-striazine ring anchored small CeO2 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 TiO2.

Automated summary

This study presents a facile strategy of using g-C3N4 as an anchor to load highly dispersed ultrasmall CeO2 clusters on g-C3N4/TiO2. The photocatalyst CeO2-g-C3N4/TiO2 demonstrates a much higher photooxidation efficiency for Hg-0 compared to other catalysts. The small CeO2 clusters are anchored via strong Ce-N coordination bonds, and a combined type II and Z-scheme transport paths accelerate the separation of photogenerated electron holes.