Phases evolution and photocatalytic activity of Cu2O films electrodeposited from a non-pH-adjusted solution

A pure-phase Cu2O film photocatalyst was successfully prepared by the electrodeposition technique from a non-pH-adjusted solution. To investigate the phase evolution and photocatalytic activity of the film, the electrodeposition was conducted at different deposition temperatures. Photocatalytic activity of the films was evaluated from methylene blue (MB) dye degradation. The Cu2O phase initially appeared at room temperature and its fraction was found to increase with increasing the deposition temperature, while the impurity phase was successfully diminished. A pure Cu2O film with a narrow optical bandgap energy of 1.96 eV was obtained at 75 & DEG;C. The multi-faceted crystals were found to form at 45 & DEG;C and became a truncated octahedral structure that possessed {111} and {100} facets as deposition temperature further increased. A preferred orientation growth of {110} facet, which is known to possess a relatively high surface energy, was produced at 75 & DEG;C. The performance of MB photodegradation enhanced gradually by increasing the deposition temperature. The increase of photocatalytic activity could be attributed to the rise of photoelectrochemical response and the decrease of resistance charge transfer because of narrowing bandgap energy, increasing Cu2O fraction, and growing a relatively high catalytic activity facet which had escalated redox reaction that decomposed MB at the photocatalyst-solution interface.

Automated summary

A pure-phase Cu2O film photocatalyst was successfully prepared using the electrodeposition technique. The deposition temperature was found to influence the phase evolution and photocatalytic activity of the film. A pure Cu2O film with a narrow optical bandgap energy of 1.96 eV was obtained at 75°C, while multi-faceted crystals were formed at 45°C. The photocatalytic activity of the Cu2O film increased with increasing deposition temperature due to the rise in photoelectrochemical response, decrease in resistance charge transfer, and growth of a high catalytic activity facet.