首页|(163064)S-scheme SrTiO_3/porous ZnO derived by pyrolysis of ZIF-8 composite with efficient photocatalytic activity for pollutant degradation

(163064)S-scheme SrTiO_3/porous ZnO derived by pyrolysis of ZIF-8 composite with efficient photocatalytic activity for pollutant degradation

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Semiconductor catalyst with high photocatalytic activity can be exploited via heterojunction. In this study, a new S-scheme SrTiO_3/porous ZnO composite was rationally devised, successfully prepared by utilizing a two-step pyrolysis of SrTiO_3/ZIF-8, and analyzed by various characterization technologies including XRD, SEM, TEM, BET, XPS, PL, UV-vis DRS, and photoelectrochemical and DFT theoretical calculations. A porous structure, tight contact, and a heterojunction formed between SrTiO_3 and porous ZnO (ZnOT) can be observed by SEM and TEM images. BET testing indicates that the SrTiO_3/porous ZnO composite (S3ZT) shows the highest specific surface area (30.37 m~2/g). The band gap values (E_g) of SrTiO_3 and ZnOT are around 3.17 and 2.95 eV, which agree with those obtained from DFT calculations. Compared to other samples, the SrTiO_3/porous ZnO composite (S3ZT) shows higher light absorption and lower transfer resistance as demonstrated by UV-vis DRS and EIS results. S3ZT presents a superior photocatalytic efficiency of 48.8% in degrading 5 mg/L methyl orange (MO) irradiated by 1 h UV-vis light, which are 7- and 1.5-fold higher than pristine SrTiO_3 and ZnOT, respectively. Moreover, based on Mott-Schottky theory, active species trapping experiments, XPS determination, and DFT calculations (energy band gap and work function), it was shown to be reasonable to utilize the S-scheme charge migration process for an explanation regarding the better photocatalytic activity of SrTiO_3/porous ZnO composite. Overall, this work will provide an effective protocol for devising and preparing semiconductor photocatalysts with S-scheme heterojunction by utilizing the superior characteristics of MOFs.

SrTiO_3Porous ZnOZIF-8 pyrolysisS-scheme mechanismMethyl orange photodegradation

Cheng Cheng、Jian Wang、Zhihao Zhao

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College of Materials Science and Engineering, Nanjing Tech University, No. 30 Puzhu Road (S), Nanjing 211816, PR China

2022

Journal of Alloys and Compounds

Journal of Alloys and Compounds

EISCI
ISSN:0925-8388
年,卷(期):2022.896
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