Construction of a micro-nano reactor assembled by TiO 2 /N-C ultrathin sheets for photocatalytic H 2 evolution.

In this paper, a series of micro-nano reactors assembled by N doped carbon coated TiO 2 heterojunction nanosheets with different thickness, named TiO 2 /N-C hollow framework (HF), TiO 2 /N-C hollow hexahedron assembled by nanosheets (HHS), and TiO 2 /N-C hollow hexahedron assembled by ultrathin nanosheets (HHUS), have been prepared by adjusting the alcoholysis rate of NH 2 -MIL-125 and then pyrolysis. Experimental and theoretical studies revealed that with the decrease of the thickness of the heterojunction nanosheet subunit, more low-coordination Ti atoms would be exposed as effective sites for photocatalytic H 2 evolution, and the interaction between the carbon layer and TiO 2 would also be enhanced, which provided a smooth migration path for the effective separation of photogenerated carriers. Thus, TiO 2 /N-C HHUS with the thinnest nanosheet subunit exhibited the best photoelectric performance and the highest photocatalytic hydrogen production activity.