Cu2FeSnS4 decorated Ni-TiO2 nanorods heterostructured photoanode for enhancing water splitting performance

Abstract

Earth-abundant and visible light sensitive Cu2FeSnS4 layer is decorated on Ni-TiO2 nanorods (CFTS/Ni-TiO2 NRs) using wet chemical approach. First, Ni doping is performed on hydrothermally grown TiO2 nanorods to achieve Ni on the surface of TiO2. After surface doping of Ni, the bandgap of TiO2 nanorod films changes from 3.0 eV to 2.79 eV. Once the layer of Cu2FeSnS4 is decorated on the Ni doped TiO2 nanorods the absorption edge of the photoanode further shifted toward lower energy. Mott-Schottky analysis revealed more than 3-fold increase in photogenerated charge carrier density in CFTS/Ni-TiO2 NRs. This heterostructured photoanodes demonstrated a significant increase in photocurrent from 0.730 mA/cm2 to 2.09 mA/cm2 (at 1.23 V vs RHE). The lifetime of photo-generated charge carriers also improves from 10.87 s to 15.36 s for CFTS/Ni-TiO2 NRs as compared to TiO2 NRs. The CFTS/Ni-TiO2 NRs exhibit excellent photoelectrochemical properties with high stability, hence this heterostructure can be a potential candidate for solar energy device applications. © 2021 Elsevier B.V.