Application of Fe3O4@BNPs@ZnS-CdS as an Efficient Photocatalyst in the Visible Region for the Removal of Organic Dyes

Abstract

Today, large amounts of wastewater containing dyes and toxic substances enter the environment through industries such as textile, printing, dyeing, spinning, and leather making; therefore, water pollution is one of the most serious environmental problems that affects the quality and health of water. For this reason, removing dyes and toxic substances from water is one of the researchers concerns. In this regard, in this study, magnetic boehmite nanocomposite modified with zinc sulfide-cadmium sulfide (Fe3O4@BNPs@ZnS-CdS (ZnS/CdS: 0.25:0.75)) was used as an efficient photocatalyst to remove direct red 16 and rhodamine B dyes in the visible region. This photocatalyst is able to remove anionic and cationic dyes. The properties of the synthesized photocatalyst were investigated using XRD, FTIR, BET, FESEM, VSM, TGA, DRS, zeta potential and EDX. The results showed that the direct red 16 dye was destroyed in a neutral pH with an efficiency of 95%, within 12 min. Regarding rhodamine B, the best result, 97% removal, was obtained at pH=3. Also, the amount of TOC decreased dramatically after dye degradation. Dye degradation for both DR16 and RhB follows first-order kinetics. The advantages of this photocatalyst include ease of separation from the environment, biocompatibility and excellent activity in visible light, recyclability, and ease of synthesis. The light source used in this research is high-pressure mercury lamp, which is cheap and durable and has excellent performance.

Keywords

• photocatalyst
• magnetic boehmite
• dye removal
• zns-cds
• high pressure mercury lamp