Enhanced photocatalytic hydrogen evolution via optimization of interfacial energy and mass flows

Abstract

As one of the most promising energy sources, photocatalysis has been investigated for several decades. Despite enormous efforts in photocatalyst engineering, the traditional triphasic system is still restricted by sluggish interfacial energy and mass transfer, which is extremely mismatched with the rapid reaction time of the photogenerated carriers. Herein, a biphasic photocatalytic system was constructed, in which surface carbonized wood and TiO 2 nanorod were used as substrate photothermal material and model photocatalyst, respectively.Under concentrated solar irradiation, the designed biphasic photocatalytic system converted liquid water into gaseous water vapor for photocatalytic hydrogen evolution. In this case, the photocatalytic hydrogen evolution rate was 24.1 μmol h -1 , 4.1 times higher than that of the traditional triphasic system. The high photocatalytic activity was attributed to the photothermal coupling effect, which greatly enhanced the energy and mass flow, and accelerated the photocatalytic reaction in thermodynamics and dynamics. This work provides a novel strategy for improving photocatalytic activity by optimizing the energy and mass flow, which may be extended to other application fields.