A novel CeO₂/MIL101(Fe) heterojunction for enhanced photocatalytic degradation of tetracycline under visible‐light irradiation

Abstract

BACKGROUND MIL101(Fe) has attracted growing attention as a potential new photocatalyst. However, the drawbacks of easy recombination of photogenerated electron–hole pairs result in unsatisfactory activity. RESULTS In this work, to enhance the photocatalytic activity of MIL101(Fe), CeO2 nanorods were attached on the surface of octahedral MIL101(Fe) to obtain a novel 1D/3D heterojunction CeO2/MIL101(Fe). The as‐synthesized samples were characterized by a series of methods. The photocatalytic activity of CeO2/MIL101(Fe) was investigated by photodegradation of tetracycline under visible‐light irradiation. Compared with pristine CeO2 and MIL101(Fe), the as‐prepared CeO2/MIL101(Fe) composite with CeO2 content of 10 wt% exhibited a superior photocatalytic activity, with a tetracycline (TC) degradation efficiency of 83.5% and a TOC removal rate of 55.7% within 120 min. CONCLUSION The enhanced photocatalytic performance is attributed to the efficient separation of photogenerated charge carriers resulting from the formation of type‐II heterojunction between CeO2 and MIL101(Fe). This work provides a new approach for the fabrication of MOF‐based photocatalysts with high activity. © 2022 Society of Chemical Industry (SCI).

Spindle-like MIL101(Fe) decorated with Bi2O3 nanoparticles for enhanced degradation of chlortetracycline under visible-light irradiation

“…The schematic synthesis procedure of Bi 2 O 3 /MIL101(Fe) is illustrated in Scheme 1 . In a manner analogous to a previous report [ 35 ], 1.35 g of FeCl 3 ·6H 2 O and 0.412 g of 1,4-benzenedicarboxulic acid (H 2 BDC) were added to 30 mL of dimethylformamide (DMF) under sonication to form a transparent brown solution. Subsequently, as-synthesized Bi 2 O 3 nanoparticles were dispersed into the above solution by sonication for 40 min.…”

“…The photocatalytic activity of the prepared samples was evaluated by the degradation of chlortetracycline (CTC) under visible-light irradiation. The test method is similar to what has been described in [ 35 ]. In a typical reaction, 30 mg of photocatalysts were added to 100 mL of a CTC solution with an initial concentration of 20 mg/L and stirred in the dark for 30 min to reach adsorption–desorption equilibrium.…”

“…It has high hydrothermal stability, low cost, good hydrophilicity, non-toxicity, and environmental friendliness [ 20 , 34 ]. Most importantly, MIL101(Fe) contains abundant iron-oxo (Fe-O) clusters, which makes it a photocatalyst with visible-light response [ 19 , 21 , 35 ]. However, pure phase MIL101(Fe), like most semiconductor photocatalysts, has inherent defects, such as low conductivity and high recombination efficiency of photogenerated electron–hole pairs [ 26 , 36 ].…”

Review on CeO2-Based Photocatalysts for Photocatalytic Reduction of CO2: Progresses and Perspectives

“…The effective separation of electrons and holes in Type II heterojunction photocatalysts is made possible by the migration of holes from the VB of photocatalyst A to photocatalyst B under light conditions. These advantages also lead to this type of catalyst being most commonly used in catalyst design. − Electrons and holes cannot be separated and transferred from photocatalyst A to catalyst B in Type III heterojunction photocatalysts because photocatalyst A’s valence band (VB) and conduction band (CB) are higher than photocatalyst B’s valence band and conduction band (Figure c).…”