Photovoltaic activity of Ti/MCM-41

Ti/MCM-41 is a well-known heterogeneous catalyst for alkene epoxidation with organic peroxides. This titanosilicate contains isolated titanium atoms forming port of a framework of mesoporous silica whose structure is formed by parallel hexagonal channels 3.2 nm in diameter. The surface area and porosity of Ti/MCM-41 are about 880 m(2) g(-1) and 0.70 cm(3) g(-1), respectively. These values are among the highest for any material. Herein, we show that Ti/MCM-41 exhibits photovoltaic activity. Dye-sensitized solar cells using mesoporous Ti/MCM-41 (2.8-5.7% Ti content) as active layer, black dye N3 as photosensitizer and I-3(-)/I- in methoxyacetonitrile as electrolyte exhibit a V-OO, J(SC) and FF of 0.44 V, 0.045 mA cm(-2) and 0.33, respectively. These values compare well against 0.75 V 4.1 mA cm(-2) and 0.64, respectively, measured for analogous solar cells using conventional P-25 TiO2. However, the specific current density (J(SC)/Ti atom) for the Ti/MCM-41 is very similar to that of P25 TiO2.