Photoelectrochemical Characterization of Spin-Coated CuBi2O4 Thin Films for Water Splitting

Wednesday, October 14, 2015
West Hall 1 (Phoenix Convention Center)
I. G. Rodríguez Gutiérrez, M. Flores Pinto, M. J. Rodríguez Pérez, G. Rodriguez-Gattorno (CINVESTAV-IPN), and G. Oskam (CINVESTAV-IPN)
Complex oxides containing multiple cations or in some cases multivalent cations such as Bi3+,5+, Co2+,3+, Sn2+,4+, have attracted much attention for photoelectrochemical applications due to their unique properties. Bismuth has a multivalent nature (Bi3+, Bi5+) that can be present at the same time in the same crystal structure in the Bi site, improving the conductivity of the material. An interesting new p-type semiconductor, which has shown high photocurrent under visible light conditions, is CuBi2O4 [1]. In this work, we present the growth of CuBi2O4 thin films prepared by spin coating method on FTO glass substrate. The precursor solution was prepared using bismuth nitrate, copper nitrate and dilute aqueous acetic acid as a solvent. The films were spin coated and annealed at 650°C.

The influence of parameters such as the heating rate during sintering and the substrate’s etching treatment on the films quality was studied. The films were characterized by X-ray diffraction, SEM, and UV-Vis spectrophotometry. We observed that the heating rate is an essential parameter to obtain a homogeneous layer. The optical response and photoelectrochemical behavior were studied as function of the film thickness. We show that the material is capable of reducing water under sunlight.

[1] L. Wei, C. Shifu, Z. Sujuan, Z. Wei, Z. Huaye, Y. Xiaoling, Journal of Nanoparticle Research 2010, 12, 1355-1366.