Hydrothermal synthesis of Fe3O4@rGO@CdS/Bi2S3 nanocomposite as an efficient, recyclable magnetic photocatalyst for photo-Fenton dye degradation and chromium VI reduction under sunlight

The use of nanocomposites for photocatalytic activities is frequently limited because the suspended catalyst particles are lost during the photocatalytic reaction, and hence, it is difficult to separate them from the reaction mixture. The combination of a magnetic core with nanocomposites could solve these challenges. Hence, in the present work, we synthesized a magnetically separatable Fe3O4@rGO@CdS/Bi2S3 photocatalyst using a simple, efficient, one-step hydrothermal method. A CdS/Bi2S3 binary nanocomposite anchored to the surface of Fe3O4 magnetic nanoparticles wrapped in reduced graphene oxide (rGO), where rGO served as an efficient protective layer for the CdS/Bi2S3 and Fe3O4 nanoparticles. The results showed that Fe3O4@rGO@CdS/Bi2S3 photocatalyst had greater stability and efficient potential for the methylene blue (MB) degradation by photo -Fenton reaction and photoreduction of hexavalent chromium Cr(VI) under natural sunlight. The prepared photocatalyst efficiently degrades 99 % of methylene blue in 70 min at neutral pH, and quick photoreduction of Cr(VI) of 98 % takes place within 40 min. After five cycles, the repeatability of the photocatalytic activity exhibited just a slight reduction in catalytic efficiency.