Facile assembly of BiVO4/protonated g-C3N4/AgI with a novel dual Z-scheme mechanism for visible-light photocatalytic degradation of Rhodamine B

Constructing Z-scheme photocatalyst is an effective strategy to achieve efficient photogenerated electron-holes separation and retain its outstanding redox ability simultaneously. In this work, a novel ternary BiVO4/protonated g-C3N4/AgI photocatalyst with a double Z-scheme mechanism is successfully constructed by electrostatic self-assembly method loading of BiVO(4)onto protonated g-C(3)N(4)and subsequently via an in situ precipitation route. Using Rhodamine B (RhB) as the target of elimination, BiVO4/protonated g-C3N4/AgI displays excellent photocatalytic performance with the 94.67% removal after 60-min visible light irradiation. The photodegradation rate constant of RhB is 0.04963 min(-1), which faster than pristine BiVO4(0.0004 min(-1)), BiVO4/protonated g-C3N4(0.0209 min(-1)) and BiVO4/AgI (0.0317 min(-1)), respectively. Such enhancement in photocatalytic activity is correlated to improved light absorption, faster charge carrier separation and transportation as well as more powerful redox ability originating from the formation of double Z-scheme heterostructure. Also, the as-prepared ternary sample exhibits high stability after four cycles of the photodegradation reaction. Furthermore, the possible photocatalytic mechanism of BiVO4/protonated g-C3N4/AgI is also proposed. Therefore, we believe that this work can provide insights into the understanding the significant role of design and synthesis the double Z-scheme in semiconductor heterostructure system for environmental remediation.

Automated summary

In this study, a novel ternary BiVO4/protonated g-C3N4/AgI photocatalyst with a double Z-scheme mechanism was successfully constructed, exhibiting excellent photocatalytic performance in eliminating Rhodamine B under visible light irradiation for 60 minutes with a removal rate of 94.67%. The sample also showed high stability after four cycles of photodegradation reaction.