Synthesis of vis/NIR-driven hybrid photocatalysts by electrostatic assembly of NaYF4:Yb, Tm nanocrystals on g-C3N4 nanosheets

• An electrostatic assembly method is demonstrated for the preparation of hybrid materials consisting of both hydrophobic and hydrophilic nanostructures.
• A hybrid photocatalyst of g-C3N4 nanosheets and NaYF4:Yb, Tm upconversion nanocrystals is developed.
• Hybrid g-C3N4/NaYF4:Yb, Tm photocatatlysts can be activated under both visible and NIR lights.
• Working mechanism of g-C3N4/NaYF4:Yb, Tm photocatalysts is proposed.

Graphitic (g-) C3N4 is a promising visible light-driven photocatatalyst but it has a narrow absorption in the solar spectrum. To broaden its light utilization, here we present a strategy to integrate upconversion nanocrystals into g-C3N4 nanosheets by electrostatic assembly. This hybrid photocatalyst can be activated under both visible and near-infrared (NIR) lights, showing improved photocatalytic activity in the full solar spectrum. Phase, morphology and activity of this composite photocatalyst are characterized and its working mechanism is also proposed.