The need of achieving low-impact and low-cost functional materials through sustainable and efficient methodologies is one of the goals of the current research in the field of materials science and energy storage. In this study, a new facile route for obtaining battery-like electrode Bi-based films is presented. Specifically, ∼1.3 μm-thick β-Bi2O3 films were prepared from oxynitrate via a simple sol-gel/elution process upon titanium foils, followed by annealing in forming gas at 350°C. A multi-technique approach, involving Raman, X-ray Photoelectron Spectroscopy, X-ray Diffraction, Scanning Electron Microscopy and optical characterization, demonstrates the formation of a nanocrystalline porous bismuth oxide (20–30 nm in size) consisting of β-Bi2O3 phase with the crucial presence of Bi0. Annealing at 350°C in different environments (i.e. air and N2), do not produce crystalline phases. The reported method improves …