Synthesis of Ni-poor NiO nanoparticles for p-DSSC applications

•Synthesis of nickel precursor Ni3O2(OH)4 nanoparticles with high Ni3+/Ni2+ ratio.•Synthesis of Ni-poor NiO nanoparticles by thermal decomposition of Ni3O2(OH)4.•Synthesis of N-doped NiO nanoparticles by ammonolysis of Ni3O2(OH)4.

To improve the performances of p-Dye Sensitized Solar Cell (p-DSSC) for the future, the synthesis of modified p-type nickel oxide semiconductor, commonly used as photocathode in such devices, was initiated with Ni3O2(OH)4 as precursor. This specific nickel oxyhydroxide was first characterized by X-ray photo-electron spectroscopy and magnetic susceptibility measurements. Then its thermal decomposition was thoroughly studied in order to control the particles size of the as-prepared NiO nanopowders. Low temperature decomposition in air of this precursor allows the formation of Ni1−xO nanoparticles with a large amount of Ni vacancies and specific surface areas up to 250 m2 g−1. Its ammonolysis at 250 °C leads to nanostructured N-doped NiO (NiO:N) materials.

Graphical abstractTEM image of the Ni3O2(OH)4 precursor.Figure optionsDownload full-size imageDownload as PowerPoint slide