Near-Infrared (NIR) Silver Sulfide (Ag 2 S) Semiconductor Photocatalyst Film for Degradation of Methylene Blue Solution

• Published in: Materials Vol. 16; no. 1; p. 437
• Main Authors: Mubarokah, Zahrah Ramadlan, Mahmed, Norsuria, Norizan, Mohd Natashah, Mohamad, Ili Salwani, Abdullah, Mohd Mustafa Al Bakri, Błoch, Katarzyna, Nabiałek, Marcin, Baltatu, Madalina Simona, Sandu, Andrei Victor, Vizureanu, Petrica
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 03.01.2023; MDPI
• Subjects: Cadmium selenide; Caustic soda; Cellulose; cellulose film; Chemicals; Commercialization; Crystal structure; Crystalline cellulose; Crystallites; Degradation; Dyes; Efficiency; Environmental impact; Fourier transforms; Functional groups; Infrared spectroscopy; Light; Metal oxides; Methods; Methylene blue; Near infrared radiation; near-infrared irradiation; Oxidation; Photocatalysis; Photocatalysts; Pollutants; Polyvinyl alcohol; Rarefaction; Silver; Silver nitrate; silver sulfide; Sulfide compounds; Sunlight; Synthesis; Textiles; Water treatment; Zinc oxides; methylene blue; cellulose film; silver sulfide; near-infrared irradiation; photocatalysis
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16010437

A silver sulfide (Ag S) semiconductor photocatalyst film has been successfully synthesized using a solution casting method. To produce the photocatalyst films, two types of Ag S powder were used: a commercialized and synthesized powder. For the commercialized powder (CF/comAg S), the Ag S underwent a rarefaction process to reduce its crystallite size from 52 nm to 10 nm, followed by incorporation into microcrystalline cellulose using a solution casting method under the presence of an alkaline/urea solution. A similar process was applied to the synthesized Ag S powder (CF/syntAg S), resulting from the co-precipitation process of silver nitrate (AgNO ) and thiourea. The prepared photocatalyst films and their photocatalytic efficiency were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-visible spectroscopy (UV-Vis). The results showed that the incorporation of the Ag S powder into the cellulose films could reduce the peak intensity of the oxygen-containing functional group, which indicated the formation of a composite film. The study of the crystal structure confirmed that all of the as-prepared samples featured a monoclinic acanthite Ag S structure with space group P /C. It was found that the degradation rate of the methylene blue dye reached 100% within 2 h under sunlight exposure when using CF/comAg S and 98.6% for the CF/syntAg S photocatalyst film, and only 48.1% for the bare Ag S powder. For the non-exposure sunlight samples, the degradation rate of only 33-35% indicated the importance of the semiconductor near-infrared (NIR) Ag S photocatalyst used.