Robust Cr(VI) reduction over hydroxyl modified UiO-66 photocatalyst constructed from mixed ligands: Performances and mechanism insight with or without tartaric acid

Yu Hang Li, Xiao Hong Yi, Yu Xuan Li, Chong Chen Wang, Peng Wang, Chen Zhao, Weiwei Zheng

Research output: Contribution to journalArticlepeer-review

Abstract

Hydroxyl modified UiO-66 ((OH)2-UiO-66-X%, X represents the mass content ratio of introduced 2,5-dihydroxyterephthalic acid) was prepared via a solvothermal reaction between zirconium tetrachloride, benzene-1,4-dicarboxylic acid (H2BDC), as well as 2,5-dihydroxyterephthalic acid (H2BDC-(OH)2). It was found that hydroxyl groups can act as the intramolecular hole scavenger to boost the photo-induced charge carrier separation to enhance Cr(VI) reduction. The photocatalytic Cr(VI) reduction activities of (OH)2-UiO-66-X% were investigated upon the irradiation of low-power ultraviolet LED light. The findings demonstrated that (OH)2-UiO-66-20% with good cyclicity and stability exhibited superior photocatalytic performances to both UiO-66 and (OH)2-UiO-66. The introduction of hydroxyl groups can also extend the light absorption region to longer wavelength in visible range, which provides possibility for displaying photocatalytic activities under sunlight. The effect of small molecule organic acid (SOAs), pH value, and co-existing inorganic ions on photocatalytic performances of (OH)2-UiO-66-20% were investigated. Tartaric acid (TA) as typical SOAs was introduced to the reaction system to further boost the photocatalytic Cr(VI) reduction via acting as hole scavenger, constructing charge-transfer-complex for quick electron transportation, and producing COO·- radicals. This work opened a new opportunity for modified MOFs for boosted elimination activities for environmental pollutants.

Original languageEnglish (US)
Article number111596
JournalEnvironmental Research
Volume201
DOIs
StatePublished - Oct 2021

Keywords

  • Hexavalent chromium
  • Hydroxyl groups
  • Photocatalytic reduction
  • Tartaric acid
  • UiO-66

ASJC Scopus subject areas

  • Biochemistry
  • Environmental Science(all)

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