Micro flowers composed of nanosheets Ag salts composite as n-p type semiconductor: an efficient photocatalyst under visible irradiation

• Published in: Journal of materials science. Materials in electronics Vol. 33; no. 30; pp. 23325 - 23340
• Main Authors: Karimi, M., Rafiee, E.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-10-2022; Springer Nature B.V
• Subjects: Catalysts; Catalytic activity; Characterization and Evaluation of Materials; Chemistry and Materials Science; Dyes; Fourier transforms; Heterojunctions; Hydroxides; Materials Science; Nanocomposites; Nanosheets; Optical and Electronic Materials; Optimization; P-type semiconductors; Photocatalysis; Photocatalysts; Photodegradation; Photoluminescence; Reaction time; Silver; Spectroscopy; Spectrum analysis
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-022-09081-0

We designed a new photocatalyst on the basis of a layered double hydroxide (MgAl-LDH), silver sulfide (Ag
2
S), and AgPW
12
O
40
(AgPW) for dye removal. Several characterization methods were used to determine the structure of the catalyst, such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), diffuse reflectance spectrophotometer (DRS), Brunauer–Emmett–Teller (BET), and photoluminescence (PL) spectroscopy. Seven catalysts with different components composition were produced. Not much change in the Ag
2
S weight percentage was more effective than AgPW. The formation of MgAl-LDH/Ag
2
S/AgPW heterojunction by the mass ratio of 4:1.2:1 along with its acceptable reusability enhanced the photocatalytic activity in photodegradation under visible light as compared to the bare MgAl-LDH, Ag
2
S, and AgPW. According to the optimization process, dye concentration of 5 mg/L, MgAl-LDH/Ag
2
S/AgPW photocatalyst with mass ratio of 4:1.2:1 (Cat IV), catalyst loading of 2 g/L, initial pH of 6, and reaction time of 90 min were selected as optimum process conditions. By these conditions, the optimum degradation of Rh.B under visible light was 99.6%. Mechanism investigation showed that
1
O
2
play the main role in photocatalytic process. Cat IV as the best composite showed prolonged life-time based on the Bode plot. Also based on the Nyquist and Tauc plots, this composite act as a superconductor. Flat band energies and donor densities of nanocomposites were evaluated from Mott–Schottky plots.