Novel indirect Z-scheme g-C3N4/Bi2MoO6/Bi hollow microsphere heterojunctions with SPR-promoted visible absorption and highly enhanced photocatalytic performance

• Published in: Chinese journal of catalysis 2020-03, Vol.41 (3), p.426-434
• Main Authors: Li, Ning, Gao, Hang, Wang, Xin, Zhao, Sujun, Lv, Da, Yang, Guoqing, Gao, Xueyun, Fan, Haikuan, Gao, Yangqin, Ge, Lei
• Format: Article
• Language: English
• Subjects: g-C3N4/Bi2MoO6/Bi; Rhodamine B; Surface plasmonic resonance effect; Visible light; Z-scheme catalyst
• ISSN: 1872-2067; 1872-2067
• DOI: 10.1016/S1872-2067(19)63478-9

The surface plasmonic resonance (SPR) effect of Bi can effectively improve the light absorption abilities and photogenerated charge carrier separation rate. In this study, a novel ternary heterojunction of g-C3N4/Bi2MoO6/Bi (CN/BMO/Bi) hollow microsphere was successfully fabricated through solvothermal and in situ reduction methods. The results revealed that the optimal ternary 0.4CN/BMO/9Bi photocatalyst exhibited the highest photocatalytic efficiency toward rhodamine B (RhB) degradation with nine times that of pure BMO. The DRS and valence band of the X-ray photoelectron spectroscopy spectrum demonstrate that the band structure of 0.4CN/BMO/9Bi is a z-scheme structure. Quenching experiments also provided solid evidence that the •O2− (at −0.33 eV) is the main species during dye degradation, and the conduction band of g-C3N4 is only the reaction site, demonstrating that the transfer of photogenerated charge carriers of g-C3N4/Bi2MoO6/Bi is through an indirect z-scheme structure. Thus, the enhanced photocatalytic performance was mainly ascribed to the synergetic effect of heterojunction structures between g-C3N4 and Bi2MoO6 and the SPR effect of Bi doping, resulting in better optical absorption ability and a lower combination rate of photogenerated charge carriers. The findings in this work provide insight into the synergism of heterostructures and the SPR absorption ability in wastewater treatment. This work constructs a novel ternary heterojunction of g-C3N4/Bi2MoO6/Bi hollow microsphere with the synergetic effect of heterojunction structures and the surface plasmon resonance (SPR) effect of Bi, resulting in an enhanced photocatalytic performance.