Enhancing catalytic activity of CuCoFe-layered double oxide towards peroxymonosulfate activation by coupling with biochar derived from durian peel for antibiotic degradation: The role of C=O in biochar and underlying mechanism of built-in electric field

• Published in: Chemosphere (Oxford) Vol. 361; p. 142452
• Main Authors: Dung, Nguyen Trung, Khiem, Ta Cong, Thao, Nguyen Phuong, Phu, Nguyen Anh, Son, Nguyen Truong, Dat, Tran Quang, Phuong, Nguyen Thu, Trang, Tran Thi, Nhi, Bui Dinh, Thuy, Nguyen Thi, Lin, Kun-Yi Adrew, Huy, Nguyen Nhat
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2024
• Subjects: Biochar; Built-in electric field; CO functional group; CuCoFe-LDO; PMS activation; PMS activation; Built-in electric field; Biochar; CuCoFe-LDO; CO functional group
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2024.142452

CuCoFe-LDO/BCD was successfully synthesized from CuCoFe-LDH and biochar derived from durian shell (BCD). Ciprofloxacin (CFX) degraded more than 95% mainly by O2•− and 1O2 in CuCoFe-LDO/BCD(2/1)/PMS system within 10 min with a rate constant of 0.255 min−1, which was 14.35 and 2.66 times higher than those in BCD/PMS and CuCoFe-LDO/PMS systems, respectively. The catalytic system exhibited good performance over a wide pH range (3–9) and high degradation efficiency of other antibiotics. Built-in electric field (BIEF) driven by large difference in the work function/Fermi level ratio between CuCoFe-LDO and BCD accelerated continuous electron transfer from CuCoFe-LDO to BCD to result in two different microenvironments with opposite charges at the interface, which enhanced PMS adsorption and activation via different directions. As a non-radical, 1O2 was mainly generated via PMS activation by C=O in BCD. The presence of C=O in BCD resulted in an increase in atomic charge of C in C=O and redistributed the charge density of other C atoms. As a result, strong adsorption of PMS at C atom in C=O and other C with a high positive charge was favorable for 1O2 generation, whereas an enhanced adsorption of PMS at negatively charged C accounted for the generation of •OH and SO4•−. After adsorption, electrons in C of BCD became deficient and were fulfilled with those transferred from CuCoFe-LDO driven by BIEF, which ensured the high catalytic activity of CuCoFe-LDO/BCD. O2•−, on the other hand, was generated via several pathways that involved in the transformation of •OH and SO4•− originated from PMS activation by the transition of metal species in CuCoFe-LDO and negatively charged C in BCD. This study proposed a new idea of fabricating a low-cost metal-LDH and biomass-derived catalyst with a strong synergistic effect induced by BIEF for enhancing PMS activation and antibiotic degradation. [Display omitted] •Durian peel-derived biochar enhances CFX degradation in CuCoFe-LDO/BCD/PMS by 1.48 times.•The role of C=O in BCD for PMS activation and 1O2 generation is confirmed by DFT calculations.•A new pathway for 1O2 generation via PMS activation by C=O is proposed.•Built-in electric field between CuCoFe-LDO and BCD accelerates electron transfer and enhances PMS activation.•CFX degradation is contributed mainly by both radical (O2•−) and non-radical (1O2).