Gradient Self-Doped CuBiO with Highly Improved Charge Separation Efficiency.

A new strategy of using forward gradient self-doping to improve the charge separation efficiency in metal oxide photoelectrodes is proposed. Gradient self-doped CuBiO photocathodes are prepared with forward and reverse gradients in copper vacancies using a two-step, diffusion-assisted spray pyrolysis process. Decreasing the Cu/Bi ratio of the CuBiO photocathodes introduces Cu vacancies that increase the carrier (hole) concentration and lowers the Fermi level, as evidenced by a shift in the flat band toward more positive potentials.

Synthesis of high quality zinc blende CdSe nanocrystals.

Highly homogeneous and luminescent CdSe colloidal nanocrystals in the less common zinc blende crystal structure have been obtained at high temperature in a noncoordinating organic solvent. The key parameter appears to be the addition of a phosphonic acid to the trioctylphosphine-selenium complex before its injection into the hot cadmium mixture, while the role of temperature is less relevant. Compared to standard (wurtzite) colloidal CdSe preparations, we find that the growth rate is considerably reduced, and the energy gap between the first two absorption bands becomes larger.

Selective photo-deposition of Cu onto the surface of monodisperse oleic acid capped TiO2 nanorods probed by FT-IR CO-adsorption studies.

A novel, non-aqueous, organometallic route to nanocomposite Cu@TiO2 materials is presented. TiO2 nanorods stabilized with oleic acid (OLA) were used as support for the photo-assisted deposition of Cu using the organometallic Cu(II) precursor [Cu(OCH(CH3)CH2N(CH3)2)2] (1). The copper precursor penetrates through the shell of OLA and is photo reduced to deposit Cu0 directly at the surface of the TiO2 rods.