Photoswitchable Activity of Mixed Bismuth Oxide (BiO x ) for Water Splitting in Neutral Media
Year: 2026
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Unary bismuth oxide (BiO x ), containing both Bi 3+ and Bi 5+ species, exhibits a photoswitchable response that, to the best of our knowledge, has not yet been reported. The material has attracted increasing attention as an anode for the oxygen evolution reaction (OER), often in combination with additional elements to enhance electrochemical performance. This study investigates the electrodeposition of BiO x and its unexplored photoswitchable properties as an anode for solar-driven enhanced water splitting. Illumination with a xenon lamp equipped with solar simulation filters reduced the deposition time from 90 to 10 min without altering the amperometric profile, offering significant energy savings and potential for scale-up. Structural and morphological characterization were performed using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) and X-ray diffraction (XRD). Chopped light voltammetry revealed that the photocurrent in neutral media has a mixed photo- and electrocatalytic contribution. Under illumination, the BiO x electrode achieved a total current density of 2.5 mA cm –2, 140 mV lower than in dark conditions. Electrochemical impedance spectroscopy (EIS) revealed a decrease in depletion layer resistance with illumination, and an electrolyte-free impedance measurement indicated that changes in intrinsic conductivity also contribute to the PEC response. Overall, illumination enhances BiO x electrocatalytic water splitting, with a particularly pronounced effect on thin-layer films.
Source: ACS Omega
Authors: André Guimarães de Oliveira, Aparecida Cristina Mauro, Marcus Vinicius David, Ana Maria Rocco
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,935
Awards: G3690646728, G5600244099
OpenAlex ID: W7133702919