A high-efficiency photoelectrochemistry of Cu2O/TiO2 nanotubes based composite for hydrogen evolution under sunlight

• Published in: Composites. Part B, Engineering Engineering, 2019-10, Vol.174, p.106969, Article 106969
• Main Authors: Trang, T.N.Q., Tu, L.T.N., Man, T.V., Mathesh, M., Nam, N.D., Thu, V.T.H.
• Format: Article
• Language: English
• Subjects: Cu2O@TiO2 based composite; H2 evolution; p-n heterojunction; Photoelectrochemistry; Sunlight irradiation
• ISSN: 1359-8368
• DOI: 10.1016/j.compositesb.2019.106969

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 H2 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 H2 evolution performance. The modified TiO2 nanotubes with 1.5 wt% Cu (Cu1.5 -TNTs) showed highest photocatalytic activity for H2 generation under sunlight due to structural integrity and uniform distribution of cuprous oxide on the surface of photocatalyst. Additionally, recyclability study for the H2 production of Cu1.5-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 H2 evolution performance under sunlight. We believe, addressing these problems would eminently assist in steady-state H2 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 H2 generation in comparison to current 2-Dimensional systems. [Display omitted] •CuxO-TiO2 nanotubes based composite were synthesized by the simple hydrothermal method for TiO2 followed by impregnation of CuxO.•The highest photocatalytic efficiency was observed to be ∼48 mmol h−1.gcat.−1 for type-II heterojunction photocatalysts.•The factors responsible for decreasing in H2 production after four cycles were examined.