Elucidation of the role of metals in the adsorption and photodegradation of herbicides by metal-organic frameworks

Nan Chieh Chiu; Jacob M Lessard; Emmanuel Nyela Musa; Logan S Lancaster; Clara Wheeler; Taylor D Krueger; Cheng Chen; Trenton C Gallagher; Makenzie T Nord; Hongliang Huang; Paul Ha-Yeon Cheong; Chong Fang; Kyriakos C Stylianou

doi:10.1038/s41467-024-45546-y

Elucidation of the role of metals in the adsorption and photodegradation of herbicides by metal-organic frameworks

Nat Commun. 2024 Feb 17;15(1):1459. doi: 10.1038/s41467-024-45546-y.

Affiliations

¹ Materials Discovery Laboratory (MaD Lab), Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR, 97331, USA.
² Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR, 97331, USA.
³ State Key Laboratory of Separation Membranes and Membrane Processes, School of Chemical Engineering and Technology, Tiangong University, 300387, Tianjin, China. huanghongliang@tiangong.edu.cn.
⁴ Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR, 97331, USA. cheongh@oregonstate.edu.
⁵ Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR, 97331, USA. chong.fang@oregonstate.edu.
⁶ Materials Discovery Laboratory (MaD Lab), Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR, 97331, USA. kyriakos.stylianou@oregonstate.edu.

^# Contributed equally.

Abstract

Here, four MOFs, namely Sc-TBAPy, Al-TBAPy, Y-TBAPy, and Fe-TBAPy (TBAPy: 1,3,6,8-tetrakis(p-benzoic acid)pyrene), were characterized and evaluated for their ability to remediate glyphosate (GP) from water. Among these materials, Sc-TBAPy demonstrates superior performance in both the adsorption and degradation of GP. Upon light irradiation for 5 min, Sc-TBAPy completely degrades 100% of GP in a 1.5 mM aqueous solution. Femtosecond transient absorption spectroscopy reveals that Sc-TBAPy exhibits enhanced charge transfer character compared to the other MOFs, as well as suppressed formation of emissive excimers that could impede photocatalysis. This finding was further supported by hydrogen evolution half-reaction (HER) experiments, which demonstrated Sc-TBAPy's superior catalytic activity for water splitting. In addition to its faster adsorption and more efficient photodegradation of GP, Sc-TBAPy also followed a selective pathway towards the oxidation of GP, avoiding the formation of toxic aminomethylphosphonic acid observed with the other M³⁺-TBAPy MOFs. To investigate the selectivity observed with Sc-TBAPy, electron spin resonance, depleted oxygen conditions, and solvent exchange with D₂O were employed to elucidate the role of different reactive oxygen species on GP photodegradation. The findings indicate that singlet oxygen (¹O₂) plays a critical role in the selective photodegradation pathway achieved by Sc-TBAPy.