Porous silicon interfaces have been modified with nitrided TiO2 (TiON) nanoparticles to develop highly efficient photoelectrodes. Photoelectrodes were prepared by impregnating the electrochemically prepared porous silicon microchannels with titanium oxynitride. Photocatalytic measurements were carried out on titanium oxynitride particles in water-methanol mixture and the results showed a dependence on the nitrogen concentration. Among the photoelectrodes used for photocurrent measurements, porous silicon impregnated with TiO2 nitrided at 600 °C showed maximum photocurrent increase after exposure to sunlight-type radiation. The enhancement in photocurrent was one order more for the porous silicon/titanium oxynitride hetero-structure than that of polished silicon/titanium oxynitride hetero-structure. Photoelectrodes thus prepared were found to have stable performance for a period of six months. This observation promises the possibility of using porous silicon/titanium oxynitride hetero-structures as efficient electrodes for photovoltaic cells. Copyright © 2010 John Wiley & Sons, Ltd.