Dual Charge-Transfer Channels Harmonize Carrier Separation for Efficient U(VI) Photoreduction.

The low efficient transfer of photogenerated electrons to an active catalytic site is a pivotal problem for the photoreduction of highly soluble hexavalent uranium [U(VI)] to low soluble tetravalent uranium [U(IV)]. Herein, we successfully synthesized a TiO/1T-MoS/reduced graphene oxide heterojunction (TTMR) with dual charge-transfer channels by exploiting the difference in Fermi levels between the heterojunction interfaces, which induced multilevel separation of photogenerated carriers. Theoretical and experimental results demonstrate that the presence of the electron buffer layer promoted the efficient migration of photogenerated electrons between the dual charge-transfer channels, which achieved effective separation of photogenerated carriers in physical/spatial dimensions and significantly extended the lifetime of photogenerated electrons.