Sustainable bamboo charcoal based nanocomposite catalysts for rapid adsorption and photo-Fenton degradation of toxic dyes

Abstract

To efficiently and completely remove organic pollutants from water, developing composite catalysts with both adsorption and photocatalytic/Fenton catalytic degradation is a very feasible solution. Herein, a new Cu_xO and g-C₃N₄ codoped bamboo charcoal (BC) composite (Cu-g-C₃N₄/BC) was prepared by the in-situ pyrolysis of Cu²⁺/melamine modified bamboo powders in N₂ atmosphere. Under the catalysis of Cu-g-C₃N₄/BC(600)/H₂O₂ system, the methylene blue (MB) and rhodamine B (RhB) dyes can be completely degraded within 10 min, and the methyl orange (MO) can be degraded within 30 min, indicating a high catalytic efficiency of the catalyst. Electron paramagnetic resonance (EPR) tests and active species trapping experiments suggested that ∙OH was the main active species in the degradation process, while the ·O₂⁻ and h⁺ played a minor role. The synergy of Cu₂O, CuO and g-C₃N₄ active sites in Cu-g-C₃N₄/BC increases the density of photogenerated electrons and promotes the separation of electron-hole pairs via the heterojunctions. The bamboo charcoal matrix plays an important role in the process of adsorbing the dyes and H₂O₂, which greatly promotes the activation of H₂O₂ and the degradation of dyes. In addition, the high conductivity of bamboo charcoal facilitates the charge transfer from the active sites to H₂O₂. The as-prepared Cu-g-C₃N₄/BC catalyst exhibits good reusability due to its structural stability. This work offers a promising bamboo charcoal catalyst with multiple active sites for the rapid elimination of persistent organic pollutants.