A novel three-dimensional purple
dandelion-like hierarchical Ag2O@CoO heterojunction with
an appropriate redox potential was
constructed by chemical precipitation of Ag2O nanoparticle
on flower-like CoO. By feat of this hierarchical structure, the Ag2O@CoO photocathode showed significantly high photoelectroreduction
activities toward p-nitrophenol (p-NP) and Cr(VI). The high performance of Ag2O@CoO was
mainly attributed to the specific structural characteristics and synergistic
effect of each chemical component. This hierarchical structure could
effectively increase the specific surface area, provide more exposed
active edges, and be beneficial for multiple light reflection/scattering
channels and light utilization efficiency. The introduction of Ag2O optimized the composition and further improved the band
structure, resulting in an improved separation of photogenerated electrons
and holes. The unique photocathode achieves a removal efficiency of
86% for photoelectrocatalytic p-NP degradation after
120 min and 95% for Cr(VI) after 40 min under visible light irradiation
with excellent stability. This research provided a simple way for
the synthesis of photoelectrocatalytic material with potential applications
in the field of environmental governance with visible light illumination.