The fabrication of bio-renewable and recyclable cellulose based carbon microspheres incorporated by CoFe₂O₄ and the photocatalytic properties

The bio-renewable cellulose based carbon microspheres through a one-step hydrothermal process (CMS) and a two-step hydrothermal plus pyrolysis process (pCMS) were prepared in the present study, respectively. The prepared carbon microspheres were then hybridized with magnetic CoFe₂O₄ to prepare recyclable photocatalyst composites. The impact of pyrolysis step on the photocatalysis performance of the composites were then investigated through degrading rhodamine B dye. The results indicated that the incorporation of both CMS and pCMS could significantly enhance the photocatalytic efficiency of the pristine CoFe₂O₄. Since the pyrolysis carbonization process led to a higher graphitization degree to the pCMS, the pCMS-CoFe₂O₄ exhibited higher photocatalytic properties than the CMS-CoFe₂O₄. Moreover, due to the existence of the magnetic CoFe₂O₄, the prepared photocatalysts could be easily separated from the water and readily reused for more cycles, achieving the goal of cleaner production through avoiding secondary pollution lead by the photocatalyst. The present study could open up a new thinking of preparing environmentally sustainable photocatalyst using bio-renewable biomass in the field of wastewater treatment.