A novel Bi12TiO20/g-C3N4 hybrid catalyst with a bionic granum configuration for enhanced photocatalytic degradation of organic pollutants.

A facile synthesis method was used to produce a novel, multi-layer hybrid carbon nitride with a granum microstromatolite structure (g-C3N4MS). This was combined with Bi12TiO20 (BTO) to produce a catalyst that was useful for decomposing hazardous pollutants. The microstructural investigation of the catalyst showed that the stacked-layer stromatolites of the g-C3N4MS were covered with BTO nanoplates to form the granum-like structures. The coupling between the BTO {310} and the g-C3N4MS {002} facets produced a heterostructure with a large contact area that efficiently separated the photo-generated electrons and holes by a reduction in the CB potential of g-C3N4MS. The photocatalytic performance of this novel catalyst was found to exhibit an optimum efficiency of 97% for the degradation of RhB within 50 min and it had a degradation rate constant that was 11.8 times better than bare BTO and 4.2 times better than g-C3N4MS. Moreover, the synthesized photocatalysts demonstrated good reusability and stability. Based on electron spin resonance results for the novel catalyst, O2- radicals were identified as the main active species in the photocatalytic reaction. A new Z-scheme heterogeneous structure was proposed that reasonably explained the photocatalytic reaction mechanism of the novel catalyst.