Constructing Fenton-like Reaction over g-C3N4/NH2-MIL-88B(Fe) Photocatalyst to Degrade Organic Contamination in Aqueous Solution

Constructing Fenton-like Reaction over g-C₃N₄/NH₂-MIL-88B(Fe) Photocatalyst to Degrade Organic Contamination in Aqueous solution

Xiyi Li, Yunhong Pi, Zhong Li, Jing Xiao*

Efficient generation of active radicals plays a key role in advanced oxidation process (AOPs) for the degradation of organic contamination from aqueous solution. To facilitate the Fenton-like process, the NH₂-Iron terephalate metal-organic framework is incorporated with carbon nitride in order to effectively covert H₂O₂ to highly reactive hydroxyl radical (•OH). The formation of •OH can be promoted via two paths, one is the Fe³⁺ in the framework acts as the trigger to convert H₂O₂ generated by the reaction between O₂ and g-C₃N₄, the other one is the heterojunction leads to the efficient transfer of photo-induced electrons to participate in the Fenton-like reaction with the addition of H₂O₂. The synergistic index in the lp-2/visible-light/H₂O₂system reached as high as 305%. The mechanism was illustrated through Electron spin resonance (ESR) spectra, as shown in Figure 1 and 2. Moreover, under visible light irradiation, the Fenton-like photocatalyst exhibit excellent degradation efficiency of MB, salicylic acid and phenol, as shown in Figure 3. This strategy of coupling metal-organic framework with carbon nitrides for Fenton-like process provides a useful and promising solution for the remediation of aqueous organic pollution under visible light irradiation.

Keywords: Fenton-like Reaction; photocatalytic degradation; visible light

 

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b.	c.
Figure 1 ESR spectra of DMPO-•OH adducts formed with irradiation time of visible light in the suspension of (a) g-C3N4/NH2-MIL-88B(Fe), (b) g-C3N4/NH2-MIL-88B(Fe)+H2O2 and (c) NH2-MIL-88B(Fe)+H2O2

 

Figure 2 The mechanism of photocatalytic Fenton-like reaction over g-C3N4/NH2-MIL-88B(Fe)

 

Figure 3 Photocatalyic degradation efficiency of MB, Salicylic Acid and Phenol. (Reaction condition: 50 mg photocatalyst, 50 ml solution at 30 mg/L, 100 µL of H2O2, >420nm)