Mechanisms of biochar enhanced Cu 2 O photocatalysts in the visible-light photodegradation of sulfamethoxazole.

Autor: Zheng MW; Department of Environmental Engineering, National Cheng Kung University, Tainan, 70101, Taiwan., Yang SJ; Department of Materials Science, National University of Tainan, Tainan, 70005, Taiwan., Pu YC; Department of Materials Science, National University of Tainan, Tainan, 70005, Taiwan., Liu SH; Department of Environmental Engineering, National Cheng Kung University, Tainan, 70101, Taiwan. Electronic address: shliu@mail.ncku.edu.tw.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2022 Nov; Vol. 307 (Pt 3), pp. 135984. Date of Electronic Publication: 2022 Aug 11.
DOI: 10.1016/j.chemosphere.2022.135984
Abstrakt: Cu 2 O nanoparticles are decorated with biochars derived from spent coffee grounds (denoted as Cu 2 O/SCG) and applied as visible-light-active photocatalysts in the sulfamethoxazole (SMX) degradation. The physicochemical properties of Cu 2 O/SCG are identified by various spectral analysis, electrochemical and photochemical techniques. As a result, the Cu 2 O/SCG exhibits the higher removal efficiency of SMX than the pristine Cu 2 O under visible light irradiation. We can observe that Cu 2 O could be incorporated onto the SCG biochars with rich oxygen vacancies/adsorbed hydroxyl groups. In addition, the Cu 2 O/SCG has the lower charge transfer resistance, faster interfacial electron transfer kinetics, decreased recombination of charge carriers and superior absorbance of visible light. The construction of band diagrams for Cu 2 O/SCG and pristine Cu 2 O via UV-vis spectra and Mott-Schottky plots suggest that the band energy shifts and higher carrier density of Cu 2 O/SCG may be responsible for the photocatalytic activity enhancements. From the radical scavenger experiments and electron paramagnetic resonance spectra, the aforementioned energy shifts could decrease the energy requirement of transferring photoinduced electrons to the potential for the formation of active superoxide radicals (·O 2 - ) via one and two-electron reduction routes in the photocatalytic reaction. A proposed degradation pathway shows that ·O 2 - and h + are two main active species which can efficiently degrade SMX into reaction intermediates by oxidation, hydroxylation, and ring opening. This research demonstrates the alternative replacement of conventional carbon materials for the preparation of biochar-assisted Cu 2 O photocatalysts which are applied in the environmental decontamination by using solar energy.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Shou-Heng Liu reports financial support was provided by Ministry of Science and Technology of Taiwan.
(Copyright © 2022 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: