Solution combustion synthesis of iron tungstate nanoparticles for photoelectrochemical water splitting towards oxygen evolution

Abstract

Iron tungstate (FeWO₄) nanoparticles were prepared by simple solution combustion technique. The preparation method discloses the first report on the synthesis of iron tungstate nanoparticles. The large-scale synthesis of iron tungstate nanoparticles was achieved and characterized by analytical instruments. The powder XRD patterns authenticated the presence of monoclinic phase of FeWO₄ with an average crystalline size of 19nm from Scherrer equation. The optical properties were deliberately assessed with vibrational spectroscopy which predicted the optical band gap of about 2.2 eV. DC and AC conductivity studies suggested that the prepared nanoparticles exhibit excellent conductivity. Furthermore, the semiconducting nature was proved with their temperature-dependent IV curves. The photoconductivity curves serve to be an evident for excellent behavior of light-induced charge carrier’s increment on the prepared iron tungstate nanoparticles. Considerate the interactions between the electrode substrate and nanostructures being an important research in determining the inherent activity of the nanostructures. Photoelectrochemical water splitting towards oxygen evolution was performed on varying the working electrode substrates (Nickel, Platinum, stainless steel, copper) in which higher photon to oxygen conversion rates were observed to be in the increasing order of Pt > SS > Ni > Cu. Herein, the prepared photo anode will revolutionize the design of tandem cells for efficient water splitting process.