Controlled synthesis of Fe 2 O 3 modified Ag- 010 BiVO 4 heterostructures with enhanced photoelectrochemical activity toward the dye degradation

• DOI: 10.1016/j.apsusc.2016.12.048
• Publication Date: 2016-12-08T21:15:54Z
• Authors: Junqi Li; Jian Zhou; Hongjuan Hao; Weijie Li
• Keywords: 02 engineering and technology; 0210 nano-technology

Abstract Crystal facet dependence is an important approach for optimizing the performance of photocatalyst. In consideration that there is a close correlation between the photoelectric conversion efficiencies and crystal facet, the monoclinic bismuth vanadate (m-BiVO 4 ) with (010) and (110) crystal facets has drawn attention. We designed the Ag nanoparticles modified the (010) facet of the BiVO 4 (Ag- 010 BiVO 4 ) and then the Ag- 010 BiVO 4 heterogeneous nanostructure was modified by the Fe 2 O 3 nanoparticles. In the Fe 2 O 3 modified Ag- 010 BiVO 4 , the (110) facet of the BiVO 4 was only modified by the Fe 2 O 3 nano-particles to construct the n-n heterojunction structure. Simultaneously, the Z-scheme system was fabricated on the (010) facet of the BiVO 4 , where was modified by the Ag and Fe 2 O 3 nano-particles. We investigated its photoelectrochemical (PEC) and photocatalytic activities by the measurement of the electrochemical performance and degradation of methyl orange (MO). The Ag species in the system is only treated as the solid state electron mediator. As was expected, the Fe 2 O 3 modified Ag- 010 BiVO 4 heterojunction structure exhibited the highest photocurrent density and the smallest impedance. Besides, the Fe 2 O 3 modified Ag- 010 BiVO 4 heterojunction structure exhibited excellent redox ability and the MO could be degraded 92% after 150 min. It is worth noting that the outstanding performance should be attributed to the synergistic effect of n-n and Z-scheme system in the different facets, which facilitated the separation of holes and electrons in the opposite direction.