Highly Visible Light Responsive, Narrow Band gap TiO(2) Nanoparticles Modified by Elemental Red Phosphorus for Photocatalysis and Photoelectrochemical Applications

This paper reports that the introduction of elemental red phosphorus (RP) into TiO(2) can shift the light absorption ability from the UV to the visible region, and confirmed that the optimal RP loading and milling time can effectively improve the visible light driven-photocatalytic activity of TiO(2). The resulting RP-TiO(2) nanohybrids were characterized systematically by a range of techniques and the photocatalytic ability of the RP-TiO(2) photocatalysts was assessed further by the photodegradation of a model Rhodamine B pollutant under visible light irradiation. The results suggest that the RP-TiO(2) has superior photodegradation ability for model contaminant decomposition compared to other well-known photocatalysts, such as TiO(2) and other reference materials. Furthermore, as a photoelectrode, electrochemical impedance spectroscopy, differential pulse voltammetry, and linear scan voltammetry were also performed in the dark and under visible light irradiation. These photoelectrochemical performances of RP-TiO(2) under visible light irradiation revealed more efficient photoexcited electron-hole separation and rapid charge transfer than under the dark condition, and thus improved photocatalytic activity. These findings show that the use of earth abundant and inexpensive red phosphorus instead of expensive plasmonic metals for inducing visible light responsive characteristics in TiO(2) is an effective strategy for the efficient energy conversion of visible light.