Synthesis and catalysis properties of magnetic CuFe₂O₄/cellulose composites

Magnetic CuFe₂O₄/cellulose nano crystals (CuFe₂O₄/CNC) composite was presented via a facile one-step solvothermal method. The catalytic reduction of 4-nitrophenol (4-NP) was tested with the addition of NaBH₄. The results show that the prepared superparamagnetic CuFe₂O₄/CNC composite is a cubic spinel crystal structure with the nano particle size of 10 nm, presenting the saturation magnetization of 33.15 emu·g^-1. Compared with CuFe₂O₄ nano particles, the CuFe₂O₄/CNC composite shows a higher specific surface area of 89.9 m²·g^-1 (the specific surface area of CuFe₂O₄ nano particles is 53.9 m²·g^-1). The CNC helps to improve the monodispersity of CuFe₂O₄ nano particles and absorbs 4-NP to facilitate the mass transfer rate positively. The CuFe₂O₄/CNC composite is conducted to catalytic reduction of 4-NP. The dynamic kinetics of the catalytic reduction is the first order process. When 0.2 g CNC is added, CuFe₂O₄/CNC composite can catalyze the reduction of 4-NP (100 μL, 0.005 mol·L^-1) within 25 s, showing a high catalytic activity. The conversion rate of 4-NP can still reach 90% even after 5 cycles.