Reduced band gap SrTiO3 thin film prepared by magnetron sputtering for the oxygen evolution reaction.

Abstract

The development of non-precious element-based materials that are stable, binder-free and prepared on economical and environmentally sustainable substrates will be fundamental to the growth of the green hydrogen industry. SrTiO3 perovskites (STO) are very interesting materials due to their high bandgap, the possibility of its modulation and high stability. However, their high resistivity causes a decrease in the efficiency of the oxygen evolution reaction (OER). In this work, STO thin films with an average thickness of 70.95 nm were prepared directly on carbon paper (CP) by magnetron sputtering without the use of stabilizing binder. The samples where thermally treated in reductive atmosphere (STO-TT) and results a film with a low optical band gap of 3.06 eV. The electrochemical study for OER reaction reveals a better behavior of the STO-TT sample in terms of overpotential, Taffel slope and stability for 24 hours.