Constructing bimetallization and hydroxylation in metal-organic framework for efficient Cr(VI) photoreduction

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) are effective for Cr(VI) removal due to porosity and tunability.
• Simple MOF hybridization hinders photogenerated carrier separation, limiting photocatalytic efficiency.

Purpose of the Study:

• To synthesize a novel Al-doped and hydroxyl-functionalized Zr-based MOF (Al/Zr-UiO-66-(OH)2) for enhanced Cr(VI) photocatalytic reduction.
• To investigate the impact of Al doping and hydroxylation on MOF bandgap and charge carrier separation.

Main Methods:

• Synthesis of Al/Zr-UiO-66-(OH)2 via bimetallization and hydroxylation.
• Characterization using various techniques to confirm structure and properties.
• Photocatalytic reduction experiments under visible light, including trapping studies, EPR, and XPS analysis.

Main Results:

• Al/Zr-UiO-66-(OH)2 exhibited a reduced bandgap and enhanced photogenerated charge separation.
• Achieved 99.3% Cr(VI) removal within 2 hours under visible light.
• Photocatalytic rate was 74 times higher than pristine UiO-66, attributed to electrons and ·O2- radicals.

Conclusions:

• Al/Zr-UiO-66-(OH)2 is a highly efficient photocatalyst for Cr(VI) reduction.
• Dual strategies of bimetallization and hydroxylation offer a viable approach for designing advanced MOF photocatalysts.
• This research provides a promising strategy for developing MOF-based materials for environmental remediation applications.