S-scheme CdS QDs/La-Bi2WO6 photocatalysts are successfully designed and synthesized by coupling element doping and constructing. The photocatalytic mechanism of the S-scheme heterojunction was analyzed by the test of photocatalytic performance, crystal characterization and theoretical calculation, which provides an approach to design advanced photocatalysts by coupling element doping and constructing heterostructures.
Finding effective strategies to design efficient photocatalysts and decompose refractory organic compounds in wastewater is a challenging problem. Herein, by coupling element doping and constructing heterostructures, S-scheme CdS QDs/La-Bi2WO6 (CS/LBWO) photocatalysts are designed and synthesized by a simple hydrothermal method. As a result, the RhB degradation efficiency of the optimized 5% CS/LBWO reached 99% within 70 min of illumination with excellent stability and recyclability. CS/LBWO shows improvement in the adsorption range of visible light and promotes electron–hole pair generation/migration/separation, attributing the superior degradation performance. The degradation RhB mechanism is proposed by a free radical capture experiment, electron paramagnetic resonance, and high-performance liquid chromatography-mass spectrometry results, indicating that h+ and •O2– play a significant role during four degradation processes: de-ethylation, chromophore cleavage, ring opening, and mineralization. Based on in situ irradiated X-ray photoelectron spectroscopy, Mulliken electronegativity theory, and the work function results, the S-scheme heterojunction of CS/LBWO promotes the transfer of photogenerated electron–hole pairs and promotes the generation of reactive radicals. This work not only reports that 5% CS/LBWO is a promising photocatalyst for degradation experiments but also provides an approach to design advanced photocatalysts by coupling element doping and constructing heterostructures.
Jing Ning†, Bohang Zhang†, Letu Siqin, Gaihui Liu, Qiao Wu, Suqin Xue, Tingting Shao, Fuchun Zhang*, Weibin Zhang*, Xinghui Liu*
How to cite:
J. Ning, B. Zhang, L. Siqin, G. Liu, Q. Wu, S. Xue, T. Shao, F. Zhang, W. Zhang, X. Liu, Exploration 2023, 20230050.