The research on the surface photovoltaic properties of porphyrin affected by nano-TiO2

The degeneration of energy level of alpha, beta, gamma, delta-tetrahydroxylphenylporphyrin (THPP) and red shift of the photovoltage peaks of THPP are observed as the size of nano-TiO2 decreasing using surface photovoltage (SPV) technique, while that of alpha, beta, gamma, delta-tetraphenylporphyrin (TPP) have little change. The reason for that is the existence of hydroxyls of THPP, which interact with the surface of nano-TiO2. This difference was also demonstrated by IR spectrum. (C) 2004 Elsevier B.V. All rights reserved.