hr 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 TiO2???x/1T-MoS2/reduced graphene oxide hetero-junction (T2???xTMR) 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 photo -generated carriers in physical/spatial dimensions and significantly extended the lifetime of photogenerated electrons. The migration of photogenerated electrons to the active catalytic site after multilevel spatial separation enabled the T2???xTMR dual co-photocatalyst to remove 97.4% of the high concentration of U(VI) from the liquid-phase system within 80 min. This work provides a practical reference for utilizing multiple co-catalysts to accomplish directed spatial separation of photogenerated carriers.

Automated summary

A TiO2-x/1T-MoS2/reduced graphene oxide hetero-junction (T2-xTMR) was synthesized, enabling multi-level spatial separation of photogenerated carriers and promoting efficient migration and extended lifetime of photogenerated electrons. The T2-xTMR dual co-photocatalyst exhibited high efficiency in removing 97.4% of U(VI) from the liquid-phase system within 80 minutes. This work provides practical guidance for achieving directed spatial separation of photogenerated carriers using multiple co-catalysts.