Green one-pot preparation of α-Fe₂O₃@carboxyl-functionalized yeast composite with high adsorption and catalysis properties for removal of methylene blue

Herein, the α-Fe₂O₃@carboxyl-functionalized yeast composite (α-F@CFYC) was synthesized by direct oxidation of yeast with K₂FeO₄ and used as a novel adsorbent/heterogeneous Fenton catalyst for removal of methylene blue (MB). The obtained α-F@CFYC was fully characterized by scanning electron microscopy, EDX, X-ray diffraction analysis, Fourier-transform infrared, thermogravimetry, and X-ray photoelectron spectroscopy, respectively, and the corresponding results showed that α-Fe₂O₃ nanoparticles were successfully obtained and deposited on yeast surface, as well as more functional groups were introduced/exposed on yeast surface. Furthermore, various influence parameters (eg, contact time, initial pH, and MB concentration) on the adsorption/catalysis ability of α-F@CFYC for MB have been investigated in detail under ambient conditions. As a result, owing to the synergetic effect of the loaded α-Fe₂O₃ and the introduced/exposed functional groups on yeast surface, the as-obtained α-F@CFYC exhibited high adsorption capacities and good catalysis degradation properties for MB.