High Efficient Photocatalytic Degradation of p-Nitropheno! on a Unique Cu_2O/TiO_2 p-n Heterojunction Network Catalyst

摘要

p-Nitrophenol (PNP) is a difficultly decomposed organic pollutant under solar light in the absence of strong oxidants. This study shows that under artificial solar light PNP can be effectively degraded by a Cu_2O/TiO_2 p-n junction network which is fabricated by anodizing Cu~0 particles-loaded TiO_2 nanotubes (NTs). The network is composed of p-type Cu_2O nanowires on the top surface and Cu_2O nanoparticles on the inner walls of the n-type TiO_2 NT arrays. The Cu_2O/TiO_2 network shows much higher degradation rate (1.97 μg/min cm~2) than the unmodified TiO_2 NTs (0.85 μg/min cm~2). The enhanced photocatalyrjc acrtivrty can be attributed to the extended absorption in the visible resulting from the Cu_2O nanowire networks and the effective separation of photogenerated carriers driven by the photoinduced potential difference generated at the Cu_2O/TiO_2 p-n junction interface.