Integration of nanosized ZIF-8 particles onto mesoporous TiO ₂ nanobeads for enhanced photocatalytic activity

Hexavalent chromium, or Cr(VI), is a highly toxic contaminant in industrial wastewater that needs to be treated before being released. A Zeolitic Imidazolate Framework ZIF-8 was assembled on the surface of mesoporous TiO2 beads to achieve a TiO2/ZIF-8 heterostructure for photocatalytic reduction of Cr(VI). The TiO2/ZIF-8 nanobeads exhibited remarkable photocatalytic activity of Cr(VI) reduction relative to that of pristine TiO2 nanobeads attributed to the strong Cr(VI) adsorbing properties of ZIF-8 and improved charge transfer efficiency of TiO2/ZIF-8. This work illustrates a strategy for enhanced photocatalysis by modifying the metal oxide catalyst with high surface area Zeolitic Imidazolate Framework to improve adsorption and charge transfer efficiency.