Enhanced photocatalytic performance of g-C 3 N 4 /Bi 4 Ti 3 O 12 heterojunction nanocomposites

Two types of g-C3N4/Bi4Ti3O12 p-n heterostructures were prepared by a simple mixing–calcining method. One is constructed from Bi4Ti3O12 (BTO) nanoparticles and g-C3N4 nanosheets (NS), and the other is constructed from BTO nanoparticles and g-C3N4 nanoparticles (NP). The structures, morphologies, optical and electrochemical properties of the samples were systematically characterized. PL spectra, EIS spectra and photocurrent responses demonstrate an effective separation of photogenerated electron-hole pairs for the composites. The photocatalytic performance of the composites was evaluated by the degradation of rhodamine B (RhB) under simulated-sunlight irradiation, revealing that they exhibit an enhanced photocatalytic activity compared to bare BTO and g-C3N4. The highest photocatalytic activity is observed for the composites with g-C3N4 content centered around 10%. Furthermore, g-C3N4(NP)/BTO composites integrated from BTO and g-C3N4 nanoparticles possess a superior photocatalytic activity compared to those integrated from BTO nanoparticles and g-C3N4 nanosheents.