Cobalt oxide/copper bismuth oxide/samarium vanadate (Co3O4/CuBi2O4/SmVO4) dual Z-scheme heterostructured photocatalyst with high charge-transfer efficiency: Enhanced carbamazepine degradation under visible light irradiation

• Published in: Journal of colloid and interface science Vol. 603; pp. 666 - 684
• Main Authors: Mafa, Potlako J., Malefane, Mope E., Idris, Azeez O., Mamba, Bhekie B., Liu, Dan, Gui, Jianzhou, Kuvarega, Alex T.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-12-2021
• Subjects: Carbamazepine; Charge-transfer-efficiency; Co3O4/CuBi2O4/SmVO4 nanocomposite; Dual Z-scheme heterojunction; Photocatalysis; Solar light; Co3O4/CuBi2O4/SmVO4 nanocomposite; Dual Z-scheme heterojunction; Solar light; Charge-transfer-efficiency; Photocatalysis; Carbamazepine
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2021.06.146

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Herein, a dual Z-scheme heterojunction photocatalyst consisting of Co3O4, CuBi2O4, and SmVO4 for carbamazepine (CBZ) degradation was synthesised and characterised by XRD, FTIR, UV–Vis DRS, XPS, FE-SEM, and TEM. The reduction in electron-hole recombination was evaluated by PL, LSV, and EIS analysis. The heterojunction, Co3O4/CuBi2O4/SmVO4 (CCBSV) showed enhanced photocatalytic activity of 76.1% ± 3.81 CBZ degradation under visible light irradiation, ascribed to the improved interfacial contact, visible light capturing ability, and enhanced electron-hole separation and transportation through the formation of Z-scheme heterojunction. The formation of dual Z-scheme was confirmed by active radical experiments and XPS analysis that helped to prose the mechanism of degradation. The catalyst showed sustained stability after 4 cycles of reuse. Ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was employed to identify the degradation by-products of CBZ, and a possible mechanistic degradation pathway was proposed. This study provided an insight into the development of efficient dual Z-scheme heterojunction photocatalyst for remediation of CBZ which can be extended to other organic pollutants.