Self-sacrificing MOF-derived hierarchical porous In2S3 nanostructures with enhanced photocatalytic performance

ABSTRACT Fabrication of porous hierarchical structures is an effective method to improve the photo-absorption capability of photocatalysts by enhancing the photogenerated charge separation and transfer. In-based metal-organic frameworks (MOFs) are utilized as self-sacrificial templates to synthesize various hierarchical In 2 S 3 photocatalysts including hollow nanotubes/microtubes/ spheres and dodecahedrons by the sulfidation process. The porous hierarchical structures improve multiple refraction and reflection of the incident light, provide larger surface areas , and increase the light utilization and phase separation efficiency of the photogenerated carriers. As a result, the photocatalytic efficiency is much higher than that of the bulk and commercial In 2 S 3 . In particular, the hollow In 2 S 3 nanotubes (HNTs) have the best photocatalytic properties boosting degradation rates of organic pollutants that are 135.6 and 446.9 times than those of the bulk and commercial-grade In 2 S 3 , respectively. Theoretical calculations, optical/electrical characterization, and free radical trapping experiments reveal that under the condition of light, the photogenerated electron hole pairs produced in In 2 S 3 -HNT can effectively separate due to its hierarchical porous structure. So, the In 2 S 3 -HNT can accumulate more reactive oxygen radicals. This novel self-sacrificial template method has large potential in the design and fabrication of hierarchical high-efficiency photocatalysts.