Spontaneous and passive photoinduced charge carrier separation in CNT-ZnIn2S4 network composites under a magnetic field

Photoinduced charge carrier separation derived by magnetic fields has attracted increasing attention for its ability to wireless regulate powder photocatalysts. In this study, carbon nanotubes (CNT) were used as network conductors to link ZnIn2S4 nanosheets. The electron highway in CNT spontaneously enhanced the photoinduced charge carrier transfer between ZnIn2S4 nanosheets. The photocatalytic H2 evolution rate of the 3 wt % CNT-ZIS composite increased to ∼210 % compared to that of pure ZIS under 300 W xenon lamp illumination. Additionally, in a magnetic field with relative motion, the Lorenz force on photoinduced electrons and holes suppressed their recombination, while the motional electromotive force along CNT accelerated the electron transfer to surface active sites. Therefore, the photocatalytic H2 evolution rate further increased to 290 %. The spontaneous and passive photoinduced charge carrier separation in CNT-ZnIn2S4 network composites under a magnetic field contributed to enhanced photocatalysis. Moreover, CNT-based network semiconductor composites can be mass-produced at low cost. Magnetic field-enhanced photocatalysis can be universally achieved without limitation caused by intrinsic band structures.