Efficient Electricity Generation and Degradation of Organic Pollutants in Wastewater Using Ag-BiOI Photoactivated Fuel Cell

A visible-light-driven photo fuel cell (PFC) system, consisting of a Ag-BiOI/ITO photoanode and a Pt photocathode, was used to generate electricity by using wastewater organic compounds as electrolyte and fuel. The prepared BiOI and Ag-BiOI/ITO photoanodes were characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (DRS) to examine the surface structure, chemical composition, and the properties of light absorption. The photoactivity of Ag-BiOI/ITO photoanodes was evaluated in the term of the electricity generation efficiency and degradation efficiency for recalcitrant organic pollutants. Compared with a BiOI/ITO photoanode, it was found that the efficiency of electricity generation using the Ag-BiOI/ITO photoanode was significantly higher in PFC system under visible light. Similarly, the photocatalytic degradation efficiency of wastewater organic pollutants using Ag-BiOI/ITO photoanode was significantly higher than that of BiOI/ITO. The enhancement in the electricity generation efficiency and degradation efficiency for wastewater organic pollutants is attributed to the action of these dopants Ag on BiOI surface, which play a key role by driving the electrons to the cathode via an external circuit.