Design, engineering, and performance of nanorod-Fe₂O₃@rGO@LaSrFe_2-nCo _nO₆ (n=0, 1) composite architectures: The role of double oxide

A visible light responsive heterojunction system composed of Fe2O3 nanorods (NF), reduced graphene oxide (rGO) and double oxide perovskites (LaSrFe2-nConO6, n = 1 (LSFC) and 0 (LSFF)) was rationally designed for an effective photoelectrochemical water splitting. The photoelectrodes were characterized in terms of structure, surface, physicochemical and functional properties with a focus on the electronic structure (e.g., the density of electronic states, band-edge, Fermi level positions), which was gauged from UPS, Kelvin probe (KP) and spectroelectrochemical (SE-DRS) measurements. The KP measurements not only revealed the successful and efficient contact of the materials with different work functions but also showed the drift direction of photogenerated charges. In the studied systems, the transparent, thin layer of rGO facilitates the hole transfer from NF (photoabsorber) to perovskites (electrocatalyst). The hydrogen conversion efficiency under visible and solar simulated irradiation for NF@rGO@LSFF reached remarkable values of 3.61 % and 1.13 % (STH), respectively.