One-step synthesis of three-dimensional mesoporous Co3O4@Al2O3 nanocomposites with deep eutectic solvent: An efficient and stable peroxymonosulfate activator for organic pollutant degradations

• Published in: Nano research Vol. 16; no. 8; pp. 11430 - 11443
• Main Authors: Wang, Yuchen, Rong, Kai, Wei, Jiale, Chang, Shanlei, Yu, Dengbin, Fang, Youxing, Dong, Shaojun
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.08.2023; Springer Nature B.V
• Subjects: Acetaminophen; Aluminum oxide; Analgesics; Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Catalysis; Catalysts; Chemistry and Materials Science; Cobalt; Cobalt oxides; Condensed Matter Physics; Contaminants; Degradation; Dispersion; Lamellar structure; Leaching; Low level; Materials Science; Nanocomposites; Nanoparticles; Nanotechnology; Organic contaminants; Oxidation; Oxytetracycline; Performance degradation; Pollutants; Porosity; Research Article; Rhodamine; Solvents; Thermal stability; Water pollution; deep eutectic solvent; organic pollutant degradation; peroxymonosulfate; hierarchical nanostructure; nanocomposite; @Al; Co; O
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-023-5819-3

The effective, stable, and secure catalysts are essential for sulfate radical (SO 4 ·− )-based advanced oxidation processes (SR-AOPs) to the degradation of organic contaminants in water. Heterogeneous supported cobalt-based catalysts are commonly used to activate peroxymonosulfate (PMS) to achieve the degradation. In this work, we synthesized Co 3 O 4 @Al 2 O 3 three-dimensional (3D) mesoporous nanocomposite (denoted as Co 3 O 4 @Al 2 O 3 3DPNC) in just one step by calcining cheap and green deep eutectic solvent (DES) solution containing Co salt. Co 3 O 4 @Al 2 O 3 3DPNC with the high specific surface area (93.246 m 2 /g), uniform pore distribution (3.829 nm) and rich porosity (0.255 cm 3 /g) were attained in a beautiful hierarchical structure which exhibited the open 3D propeller-like microstructure, two-dimensional lamellar substructure with rich folds, as well as the decoration of highly dispersed Co 3 O 4 nanoparticles on mesoporous amorphous Al 2 O 3 . The excellent chemical and thermal stability of Al 2 O 3 ensures the high stability of the catalyst, and the formation of the complex hierarchical structure makes the active Co 3 O 4 be homogenously dispersed for effective catalysis. The catalyst demonstrated outstanding performance for catalytic degradations of organic pollutants (acetaminophen, oxytetracycline, 5-sulfosalicylic acid, orange G and Rhodamine B) by generated SO 4 ·− , ·OH and 1 O 2 . With a very low cobalt content (equal to 28.2 mg/L of Co), the catalyst exhibited very high stability and excellent reusability in the recycling usages, while the leaching of the cobalt element (< 0.145 mg/L) was also at a low level. Our catalyst achieved effective degradations of acetaminophen in cycles without losing its stable hierarchical nanostructure.