Two-step hydrothermally synthesized carbon nanodots/WO₃ photocatalysts with enhanced photocatalytic performance

In this study, carbon nanodots (C-dots)/WO₃ photocatalysts were prepared via a two-step hydrothermal method. The morphologies and optical properties of the as-prepared materials were investigated. Compared with the prepared WO₃ and C-dots, the C-dots/WO₃ possessed stronger photocatalytic capability and excellent recyclability for photocatalytic elimination of Rhodamine B. For example, the achieved first order reaction rate constant of 0.01942 min^-1 for C-dots/WO₃ was ∼7.7 times higher than that of the prepared WO₃. The enhanced photocatalytic activity of C-dots/WO₃ was attributed to the enhanced light harvesting ability and efficient spatial separation of photo-excited electron-hole pairs resulting from the synergistic effect of WO₃ and C-dots. The high photocatalytic activity of C-dots/WO₃ remained unchanged even after 3 cycles of use. Meanwhile, a possible mechanism of C-dots/WO₃ for the enhanced photocatalytic activity was proposed.