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Photocatalytic performance of Z-scheme SrCO3-SrTiO3/ Ag3PO4 heterojunction for tetracycline hydrochloride degradation Yaoning Chen1,2,* , Zhen Peng1,2, Yuanping Li3,*, Yihuan Liu1,2, Yanrong Chen1,2, Yanxin Wu1,2, Ran Xu1,2, Sha Wang1,2, and Ziping Zeng1,2 1

College of Environmental Science and Engineering, Hunan University, Changsha 410082, China Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China 3 College of Municipal and Mapping Engineering, Hunan City University, Yiyang 413000, Hunan, China 2

Received: 27 July 2020

ABSTRACT

Accepted: 2 November 2020

Visible-light-driven photocatalysis, as an emerging environmental restoration technology, has become a focus of attention recently. In this work, a novel SrCO3-SrTiO3/Ag3PO4 heterojunction was successfully synthesized, and its structure, composition, and optical performance were systematically characterized. In addition, SrTiO3/Ag3PO4 was also synthesized, and its type II heterojunction had certain defects. The active species trapping experiments of SrCO3–SrTiO3/Ag3PO4 showed that OH and O2- participated during the reaction. The photodegradation efficiency of SrCO3–SrTiO3/Ag3PO4 heterojunction was 1.4 times and 2.0 times that of Ag3PO4 and SrCO3–SrTiO3, respectively. A novel Z-scheme mechanism could be used to explain the photoreaction process of SrCO3–SrTiO3/Ag3PO4. The excellent photocatalytic property was due to the enhancement of visible-light absorption, the effective separation of photogenerated charges, and the generation of abundant active species.

Published online: 16 November 2020

Ó

Springer Science+Business

Media, LLC, part of Springer Nature 2020

Introduction The growing energy dilemma [1] and environmental contamination [2–4] have aroused widespread attention. Semiconductor photocatalysts have been widely

used because they can efficiently use solar energy to produce clean energy and eliminate environmental pollution [5, 6]. Perovskite strontium titanate (SrTiO3) is one of the well-investigated semiconductor-based photocatalysts because of its low cost, flexible

Handling Editor: Joshua Tong. Yaoning Chen, Zhen Peng and Yuanping Li have contributed equally.

Address correspondence to E-mail: [email protected]; [email protected]

https://doi.org/10.1007/s10853-020-05529-y

4357

J Mater Sci (2021) 56:4356–4365

structure, and high resistance against photocorrosion [7]. However, because of the wide bandgap [8], SrTiO3 has little activity under visible-light, which leads to low solar energy conversion efficiency [9]. There are many studies on the modification of SrTiO3 by noble metals. However, noble metals deposited on the surface may transfer into the water and cause secondary contamination [10]. Therefore, a safer and more stable dopant needs to be studied. Strontium carbonate (SrCO3) is an alkaline earth metal compound with rich reserves [11], which is widely used in the fields of glass, pigments, ceramics, and so on [12]. Studies have shown that Sr(OH)2– SrCO3 had out