Synthesis of C-N Co-doped nano-CeO ₂ and dye degradation under compact fluorescent lamp irradiation

Carbon and nitrogen (C-N) co-doped nano-CeO ₂ was synthesized by the solvothermal method using hexamethylenetetramine (HMT) as a precipitator at 140 °C for 24 h. We found that the degradation of acid orange 7 (AO7) was 94.4% and 98.8% with C-N co-doped nano-CeO ₂ upon irradiation with a 100-watt high-pressure mercury lamp (HML) and a 10-watt compact fluorescent lamp (CFL), respectively. By comparison, TiO ₂ degraded 68.4% and 43.0% of the AO7 irradiated by HML and CFL, respectively. We found that the degradation efficiencies of AO7 upon irradiation with the 10-watt CFL in the presence of the samples synthesized using different precipitators decreased as follows: CeO ₂(HMT) > CeO ₂-TiO ₂(HMT) >TiO ₂(HMT) >> CeO ₂(NaHCO ₃) > CeO ₂(Na ₂CO ₃).