Bioframe synthesis of NF–TiO2/straw charcoal composites for enhanced adsorption-visible light photocatalytic degradation of RhB

Abstract

N–F codoped TiO₂/straw charcoal composites (NF–TiO₂/SC) were synthesized using a simple, bioframe-assisted sol–gel method and confirmed by XRD, SEM, EDX, TEM, N₂ adsorption–desorption, Raman, FT-IR, XPS, and UV-vis DRS measurements. It has been found that the as-synthesized catalysts formed a 3D-hierarchical structure with carbon framework after calcination. The physicochemical properties, such as BET surface area, porosity, crystallite size and pore size distribution, could be effectively controlled by adjusting the calcination temperature. NF–TiO₂/SC calcined at 450 °C exhibited higher surface area, smaller crystallite size and higher absorption in the visible light region. Under visible light irradiation, NF–TiO₂/SC450 exhibited considerably high adsorption ability and photocatalytic activity, and there existed a significant synergistic effect between adsorption and photocatalytic degradation. Furthermore, the as-synthesized catalysts exhibited good mineralization ability, and could be used repeatedly, revealing their great potential for practical applications in environmental cleanup.