Facile synthesis of Z-scheme KBiO3/g-C3N4 Z-scheme heterojunction photocatalysts: Structure, performance, and mechanism

The proper design of interfacial contact of heterojunction photocatalyst plays an important role in the transfer/ separation of interfacial charge carriers. The Z-type photocatalyst can reduce the recombination of photogenerated electron-hole pairs and retain the original redox ability. Here, KBiO3/g-C3N4 Z-scheme heterojunction photocatalysts were facile synthesized by mixing and programmed heating. Compared to pure g-C3N4 and KBiO3, the photocatalytic performance of the obtained photocatalyst on the photo-oxidative degradation of crystal violet and phenol was improved significantly. The apparent rate constants of degrading CV (Crystal Violet) and phenol were 0.15493 min(-1) and 0.02057 min(-1), which were 10 times and 4 times that of pure KBiO3, respectively. The formation mechanism of KBiO3/C3N4 Z-type heterojunction was investigated by experiments and DFT calculations. The result shows that the improvement of photo-degradation performance was attributed to the internal electric field formed by the Z-scheme photo-catalyst, which leads to the enhancement of visible light absorption and the blocking effect of light-induced electron-hole recombination.

Automated summary

The proper design of interfacial contact of heterojunction photocatalyst is crucial for the transfer/separation of interfacial charge carriers. In this study, KBiO3/g-C3N4 Z-scheme heterojunction photocatalysts were successfully synthesized, resulting in significantly improved photocatalytic performance for the degradation of crystal violet and phenol. The enhancement was attributed to the internal electric field formed by the Z-scheme photocatalyst, leading to enhanced visible light absorption and inhibition of electron-hole recombination.