A high-efficiency photoelectrochemistry of Cu_2O/TiO_2 nanotubes based composite for hydrogen evolution under sunlight

摘要

In present study, a series of single modified TiO2 nanotubes with varying amounts of Cu was synthesized via two-step chemical solution method and studied as photocatalyst for H-2 production under sunlight irradiation. The results indicate significant improvement of photocatalytic activity for TiO2 nanotubes modified Cu nanoparticles compared with pristine TiO2 attributed by the formation of the p-n heterojunction between Cu2O and TiO2. This enhanced the photo-generated charge transfer properties, resulting in an improved H-2 evolution performance. The modified TiO2 nanotubes with 1.5 wt% Cu (Cus. 5 -TNTs) showed highest photocatalytic activity for H-2 generation under sunlight due to structural integrity and uniform distribution of cuprous oxide on the surface of photocatalyst. Additionally, recyclability study for the H-2 production of Cu-1.5-TNTs material slightly decreased after four times, due to the presence of CuO phase via the oxidation of Cu2O and agglomeration phenomena, rendering them inefficient for H-2 evolution performance under sunlight. We believe, addressing these problems would eminently assist in steady-state H-2 generation performance under sunlight. Also, expanding the regime of light absorption to visible region for TiO2 1-Dimensional structure decorated Cu2O has higher photocatalytic efficiency for H-2 generation in comparison to current 2-Dimensional systems.