Abstract
A recyclable photoelectrode with high degradation capability for organic pollutants is crucial for environmental protection and, in this work, a novel CeO2 quantum dot (QDs)/Ag2Se Z-scheme photoelectrode boasting increased visible light absorption and fast separation and transfer of photo-induced carriers is prepared and demonstrated. A higher voltage increases the photocurrent and 95.8% of tetracycline (TC) is degraded by 10% CeO2 QDs/Ag2Se in 75 minutes. The degradation rate is superior to that achieved by photocatalysis (92.3% of TC in 90 min) or electrocatalysis (27.7% of TC in 90 min). Oxygen vacancies on the CeO2 QDs advance the separation and transfer of photogenerated carriers at the interfacial region. Free radical capture tests demonstrate that •O2−, •OH, and h+ are the principal active substances and, by also considering the bandgaps of CeO2 QDs and Ag2Se, the photocatalytic mechanism of CeO2 QDs/Ag2Se abides by the Z-scheme rather than the traditional heterojunction scheme. A small amount of metallic Ag formed in the photocatalysis process can form a high-speed charge transfer nano channel, which can greatly inhibit the photogenerated carrier recombination, improve the photocatalytic performance, and help form a steady Z-scheme photocatalysis system. This study would lay a foundation for the design of a Z-scheme solar photocatalytic system.
Highlights
Pollution by drug antibiotics constitutes one of the major environmental problems and tetracycline (TC), which is a common drug with high antimicrobial activity against pathogenic bacteria, ranks second globally in terms of production and use [1,2]
Extraction or degradation of TC is a critical issue for water control, environmental protection, and methods such as adsorption, biological treatment, photocatalysis, and more have been proposed [5,6,7,8]
Different amounts of CeO2 quantum dots (QDs) were incorporated into the CeO2 QDs/Ag2Se samples by changing the molar ratio of Ce/Ag
Summary
Pollution by drug antibiotics constitutes one of the major environmental problems and tetracycline (TC), which is a common drug with high antimicrobial activity against pathogenic bacteria, ranks second globally in terms of production and use [1,2]. Photocatalysis degradation based on semiconducting materials can harness solar energy for mineralization of organic pollutants and offers advantages such as no secondary pollution, low energy consumption, and practicability. In this respect, semiconducting photocatalysts such as Ag2MoO4 [10], Ag3PO4 [11], BiOI [12], Bi3O4Cl [13], Bi2MoO6 [14], CdS [15], g-C3N4 [16], and Ag2Se [17] have been proposed for removing organic contaminants [18]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
