Three CoS/CoO microspheres and their mixed matrix membranes for the highly efficient photocatalytic degradation of methyl blue

• Published in: RSC advances 2024-08, Vol.14 (35), p.25811-25819
• Main Authors: Huo, Yuping, Yu, Tanlai, Xue, Yueyuan, Zhang, Guoshuai, Song, Shengxin, Shao, Yonghua, Han, Xiaojing
• Format: Article
• Language: English
• Subjects: Catalytic activity; Deionization; Glass substrates; Membranes; Metal halide lamps; Microspheres; Near infrared radiation; Oxidation; Performance degradation; Photocatalysis; Photodegradation; Polyethylene glycol; Polyvinylidene fluorides; Portability; Raw materials; Recyclability; Size distribution
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d4ra03261f

Photocatalytic degradation technology, as one of the most important advanced oxidation technologies for environmental remediation, has attracted great attention in recent years, but designing photocatalysts with excellent photocatalytic activity and good reusability remains a challenge. Herein, three CoS/CoO microspheres (CoS/CoO-M-1 ( 1 ), CoS/CoO-M-2 ( 2 ), and CoS/CoO-M-3 ( 3 )) were prepared via a hydrothermal method using cobalt chloride hexahydrate, thiourea, deionized water and polyethylene glycol (PEG) with different polymerization degrees as raw materials, which have a uniform size distribution in the range of 5-24 μm and specific surface areas of 6.1924 m 2 g −1 ( 1 ), 6.2870 m 2 g −1 ( 2 ) and 6.6663 m 2 g −1 ( 3 ). It is worth noting that all the three CoS/CoO microspheres showed a wide optical absorption range from the ultraviolet to the near-infrared (NIR) region and a high photocatalytic activity for degrading methyl blue under visible light (500 W metal halide lamp) irradiation. In order to improve the portability and recyclability of 3 , a mixed matrix membrane ( MMM ) of 3 ( 3-MMM ) was manufactured by coating a mixture dispersion of 3 and polyvinylidene fluoride (PVDF) on a glass substrate, which not only displayed excellent photocatalytic degradation performance, but also showed good portability and reusability (cycles > 12 times). Furthermore, adsorption and photocatalytic kinetics and possible mechanisms were studied. Three CoS/CoO microspheres were solvothermally prepared by simply modulating the polymerization degree of PEG, and the mixed matrix membrane of 3 displayed excellent photocatalytic degradation performance and reusability (cycles > 12 times).