Controlled synthesis and exceptional photoelectrocatalytic properties of BiS/MoS/BiMoO ternary hetero-structured porous film.

In this work, BiS/MoS/BiMoO hetero-structured porous films were fabricated via a facile anion exchange process using the as-prepared BiMoO nanoflake array film as substrate material. The formation of BiS/MoS/BiMoO ternary hetero-structured porous film is both thermodynamically controllable and reaction time dependent. Systematic experiments were done to investigate the products at each reaction stage and disclose the relationships between the composite components and reaction temperature and time. The study showed that the energy barrier need to be overpassed when MoS and BiS were simultaneously produced. The optimized BiS/MoS/BiMoO photoelectrode exhibited significantly higher photoelectrocatalytic efficiency than BiMoO, binary BiS/BiMoO and BiS/MoS photoelectrodes. The remarkable degradation efficiency of the BiS/MoS/BiMoO photoelectrode comes from the synergy of high quality assembly and heterostructure interfaces between the three components. The optimized film assembly and stepwise band alignment in the ternary heterostructure composite contribute to visible light utilization, transport and separation of charge carriers, mass transport, and accessibility of active sites. The generated active species such as superoxide anions (O) and holes were detected to promote the decomposition of organic pollutants. The reasonable photoeletrocatalytic degradation mechanism was also proposed.