Synthesis of visible-light driven CeO2/g-C3N5 heterojunction with enhanced photocatalytic performance for organic dyes

In order to improve the photocatalytic property of g-C3N5, series of CeO2/g-C3N5 composites were prepared by calcination method. Rhodamine B (RhB), methylene blue (MB) and methyl orange (MO) were degraded under visible light to reflect the photocatalytic activity of CeO2/g-C3N5 composites. The results showed that the specific surface area of 10 wt% CeO2/g-C3N5-400 composites was 28.2 m2 g−1, while g-C3N5 was 3.9 m2 g−1. According to UV-Vis and PL results, 10 wt% CeO2/g-C3N5-400 composites have enhanced visible light absorption and low electron hole recombination rate. Thus, 10 wt% CeO2/g-C3N5-400 composites exhibited excellent photocatalytic activity. The degradation rates of RhB and MB by 10 wt% CeO2/g-C3N5-400 composites were 71 % and 99 % after 150 min. But the removal rates of RhB by CeO2 and g-C3N5 were only 14 % and 26 %. Combining trapping experiments and EPR results, •O2- was the major active species in the photodegradation reaction. Sample 10 wt% CeO2/g-C3N5-400 composites also remained outstanding photocatalytic stability after 4 cycles. The possible photocatalytic mechanism was also elucidated. In a word, CeO2/g-C3N5 composites are promising for photodegradation of organic dyes under visible light.