Bimetallic metal–organic framework-derived carbon nanocubes as efficient electrocatalysts for oxygen evolution reaction

Degradation of sulfamerazine by a novel CuxO@C composite derived from Cu-MOFs under air aeration

Most metal-organic frameworks (MOFs) are synthesized from carboxylate and metal precursors by hydrothermal process, which will consume a large amount of solvent and carboxylate. To address this issue, a new strategy for Cu-based MOFs was developed, in which the Cu-based MOFs was obtained by using abundant natural polymer (tannic acid) as one of the precursors and using high-energy ball milling to achieve a self-assembly of tannic acid and copper sulfate. Based on this strategy, a novel Cu-based MOFs derivative (Cu_xO@C composite) was synthesized by high-temperature sintering of Cu-based MOFs and used for sulfamerazine (SMR) removal via O₂ activation. The BET specific surface area and average pore size of Cu_xO@C composite were 110.34 m² g^-1 and 21.06 nm, respectively, which made Cu_xO@C composite had the maximum adsorption capacity (Q_max) for SMR of 104.65 mg g^-1 and favored the subsequent degradation of SMR. The results from XRD and XPS indicated that Cu_xO@C composite contained a lot of Cu⁰ and Cu₂O with the sizes of 76.6 nm and 9.8 nm, respectively, which led to its high performance of O₂ activation. The removal efficiency of SMR and 90.2% TOC achieved 100% and 90.2%, respectively in the Cu_xO@C/air system at initial pH of 4.0, air flow rate of 100 mL min^-1, Cu_xO@C dosage of 1 g L^-1 and reaction time of 30 min. Reactive species, including H₂O₂, OH and O₂^- radicals were detected in the Cu_xO@C/air system, and OH and O₂^- were mainly responsible for the degradation of SMR.