High-Performance Photoelectrochemical Desalination Based on the Dye-Sensitized Bi₂O₃ Anode

In this work, a solar-driven redox flow desalination system is reported, which combines a solar cell based on a Bi₂O₃ photoanode and a redox flow desalination cell through an integrated electrode. The Bi₂O₃ film was prepared through a simple one-step water bath deposition method and served as a photoanode after the coating of the N719 dye. The activated carbon (AC)-coated graphite paper served as both the integrated electrode and counter electrode. The I₃^-/I^- redox electrolyte circulates in the solar cell channel between the photoanode and intergrated electrode, while the [Fe(CN)₆]^4-/[Fe(CN)₆]^₃- electrolyte circulates in the redox flow desalination part between the integrated electrode and counter electrode. This dye-sensitized solar-driven desalination cell is capable of achieving a maximum salt removal rate of 62.89 μg/(cm²·min) without consuming any electrical power. The combination of the solar cell and redox flow desalination is highly efficient with double functions of desalination and energy release using light as a driving force. This current research work is significant for the development of efficient and stable photoanode materials in photoelectrochemical desalination.