Tuning photocatalytic activity of In2S3 broadband spectrum photocatalyst based on morphology

Efficient utilization of full solar light especially near-infrared light (NIR) is still a great challenge. Herein three In 2 S 3 nanomaterials with cubic phase and different morphologies were synthesized via hydrothermal methods by using sodium sulfide (Na 2 S), thiosemicarbazide (TSC) and thioacetamide (TAA) as sulfur sources, respectively. All the as-synthesized In 2 S 3 samples were found to be photo-active under either UV, visible or NIR light irradiation although they possess very different morphologies. The In 2 S 3 sample with irregular and plate-like nanoparticles synthesized by using Na 2 S as sulfur source shows the highest activity on photodegradation of methyl orange due to its exposure of more photoactive (311) plane than the other two In 2 S 3 samples and the occurrence of lattice oxygen. The samples that synthesized by using TSC and TAA as sulfur sources possess the morphology of hollow microspheres, which are hierarchically constructed by thinner nanosheets and cumulated by thicker platelets, respectively. The microsphere sample constructed by thinner nanosheets shows even lower photocatalytic activity than that accumulated by thicker platelets under all the tested light regions especially under longer irradiation time because of its less exposed (311) plane and lower sulfur vacancies although it possesses a far larger specific surface area than the latter. These results suggest that the exposure of more photoactive (311) plane and occurrence of lattice oxygen deserve more attention to improve the photocatalytic activity of In 2 S 3 .