Bi spheres decorated g-C3N0/BiOI Z-scheme heterojunction with SPR effect for efficient photocatalytic removal elemental mercury

This work reports the obviously promoted photocatalytic performance and superior cyclic durability of 3D fluffy and hierarchical g-C3N4@Bi/BiOI for heavy metal removal applications. The ternary structure is synthesized via moderate solvothermal method with glycol as chelating agent and reductant, and characterized by structural and morphology analysis. Optical and electrochemical properties are investigated to elucidate the mechanism of enhanced photocatalytic activity, with band structure investigations to unravel the pathway of charge carriers transfer in ternary system. Results indicate that Bi could serve as an electron mediator accepting electrons from gC3N4 via Schottky barrier and boosting electrons to BiOI irreversibly via hot electron injection, which facilitates separation and migration of electron-hole pairs. This mechanism of charge carriers transfer promotes generation of reactive oxygen species involved in photocatalytic process and in turn enhances photocatalytic activity immensely. The photocatalytic tests demonstrate that 10%g-C3N4@Bi/BiOI exhibits attractive Hg0 removal efficiency. Present work provides perspectives of design on multiple-heterostructure photocatalysts with SPR metal, which would contribute to energy conversion and environmental purification.

Automated summary

This study reports the enhanced photocatalytic performance and superior cyclic durability of 3D fluffy and hierarchical g-C3N4@Bi/BiOI for heavy metal removal applications, with a mechanism involving electron mediator transfer to promote charge separation and migration for reactive oxygen species generation.