TiO2 sensitized by red-, green-, blue-emissive carbon dots for enhanced H2 production

Abstract

Carbon dots (Cdots) with a broad light absorption range could be a potential stable sensitizer for TiO2, which is an excellent ultraviolet (UV) response photocatalyst. Herein, we systematically investigated the different color emissive Cdots-sensitized TiO2 for H2 production. Firstly, all kinds of Cdots enhanced the photocatalytic properties of TiO2. All the Cdots-sensitized TiO2 exhibits visible light H2 production due to their absorption in the visible light region. The photocurrent and H2 production amount display strong dependence on the light absorption range of Cdots. The blue-emissive Cdots endow the weak H2 production rate due to its weak absorption in the visible light. The enhanced photocatalytic activities are mainly contributed to the strong light absorbance and high-efficient charge separation. The light absorption of green- and red-emissive Cdots is another main factor for the high catalytic activities besides charge separation.