Designing a hollow MoSe2/CuS nanospheres type-II heterojunction photocatalyst with superior UV-vis-NIR absorption for photocatalytic degradation of organic pollutants.

In this work, a hollow MoSe2/CuS type-II heterojunction was fabricated using hollow MoSe2 nanospheres as the basis for structural design. UV-Vis-NIR diffuse absorption tests show that MoSe2/CuS has a broad spectral absorption to extend the optical response range from UV-Vis to NIR. The light source utilization rate and interfacial area are increased by the hollow MoSe2/CuS core-shell structure. The broad absorption ability of MoSe2/CuS can facilitate the photocatalysis process. As the electrochemical impedance of MoSe2/CuS is lower than that of the MoSe2, MoSe2/CuS has a good photogenerated carrier separation efficiency. Benefiting from the synergistic facilitation effect of the multi-level 3D hollow nanosphere and the significant space charge region in type-II heterojunction, the RhB degradation efficiency of MoSe2/CuS reached 96.0% in 120.0 min under Xe (350 W) broadband spectrum light irradiation. The photocatalysis mechanism of the hollow MoSe2/CuS core-shell structure was investigated. This work provides an insight into the application of broad spectrum semiconductor heterojunctions to solve environmental problems.