A dual S-scheme g-C3N4/Fe3O4/Bi2WO6/Bi2S3 heterojunction for improved photocatalytic decomposition of methylene blue: Proposed mechanism, and stability studies. (January 2023)

• Record Type: Journal Article
• Authors: Okab, Ayah A.; Alwared, Abeer I.
• Is Part Of: Materials science in semiconductor processing. Volume 153(2023)
• Publication Date: 2023-01
• Subjects: S-scheme heterojunction -- Magnetic nanocomposite -- Methylene blue -- Photocatalytic decomposition -- Stability studies -- Solar light simulation; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2022.107196
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: In the present work, the dual S-scheme heterojunction (g-C3 N4 /Fe3 O4 /Bi2 WO6 /Bi2 S3 ) was constructed with high superparamagnetic properties using an in-situ growth approach. The states of elements, chemical composition, optical properties, and nanostructure morphology were detailed using different characterization techniques (XRD, FTIR, BET, VSM, TEM, SEM, PL, DRS, EDS, and elemental mapping). The photodegradation performance of g-C3 N4 /Fe3 O4 /Bi2 WO6 /Bi2 S3 heterojunction was investigated against MB dye under visible-light irradiation (140 W, LED). The g-C3 N4 /Fe3 O4 /Bi2 WO6 /Bi2 S3 heterojunction exhibited complete MB degradation in 90 min, as well as 68% of total organic carbon (TOC) was eliminated. The synergistic interaction between the three effective photocatalysts in the g-C3 N4 /Fe3 O4 /Bi2 WO6 /Bi2 S3 heterojunction can efficiently inhibit the recombination rate and provide a good path for electron and hole migration. The kinetic studies revealed that the degradation constant of g-C3 N4 /Fe3 O4 /Bi2 WO6 /Bi2 S3 was 6.76, 3.4, and 3.2 times greater than that of pristine Bi2 S3, Bi2 WO6, and g-C3 N4, respectively. The radical experiments showed that OH is the main reactive species. The g-C3 N4 /Fe3 O4 /Bi2 WO6 /Bi2 S3 exhibited simple marantic separation and efficient stability in six degradation cycles. The dual S-scheme mechanism was well explained depending on the trapping experiments and photoelectrochemical measurements. This work provides an efficient and simple method for preparing bismuth-rich photocatalysts in a solid solution. This work may have broad application potential in wastewater treatment and environmental pollution control.