Microwave-assisted synthesis of C-doped TiO2 and ZnO hybrid nanostructured materials as quantum-dots sensitized solar cells

RANGEL-MENDEZA, J.; MATOS, J.; CHÁZARO-RUIZA, L.; GONZÁLEZ-CASTILLO, A.C.; BARRIOS-YÁÑEZ, G.:
Applied Surface Science, Volume 434, 15 March 2018, Pages 744-755

DOI: 10.1016/j.apsusc.2017.10.236

Abstract

The microwave-assisted solvothermal synthesis of C-doped TiO₂ and ZnO hybrid materials was performed. Saccharose, titanium isopropoxide and zinc acetate were used as organic and inorganic sources for the synthesis. The influence of temperature and reaction time on the textural and optoelectronic properties of the hybrid materials was verified. Carbon quantum-dots of TiO₂and ZnO nanostructured spheres were obtained in a second pot by controlled calcination steps of the precursor hybrid materials. A carefully characterization by adsorption-desorption N₂ isotherms, XRD, XPS, SEM, UV–vis/DR and electro- and photo-electrochemistry properties of the carbon quantum-dots TiO₂and ZnO spheres was performed. The photoelectrochemical activity of TiO₂-C and ZnO-C films proved to be dependent on the conditions of synthesis. It was found a red-shift in the energy band gap of the semiconductors with values of 3.02 eV and 3.13 eV for the TiO₂-C and ZnO-C, respectively, clearly lower than those on bare semiconductors, which is associated with the C-doping effect. From the photo-electrochemistry characterization of C-doped TiO₂ and ZnO films can be concluded that the present materials have potential applications as photoelectrodes for quantum-dots sensitized solar cells.