Photoelectrocatalytic degradation of refractory organic compounds enhanced by a photocatalytic fuel cell

[Display omitted] ► We established a novel composite system for efficient organic pollutant treatment. ► The removal efficiency of organics was evidently enhanced by the fuel cell system. ► Various important parameters influencing the removal of organics were studied. A novel composite photoelectrocatalytic system, composed of a photoelectrocatalytic reactor and a photocatalytic fuel cell (PFC), was established with the aim to efficiently degrade refractory organic compounds. The PFC is device, in which the organic “substrates” were photodecomposed and the chemical energy of organic “substrates” was converted into electrical energy simultaneously. Within the composite system, the electricity produced by PFC, rather than external power supply, was exerted on the photoelectrocatalytic reactor to serve as potential bias. The organic compound degradation performance and affecting factors of the composite system were also studied. The experimental results demonstrate that the removal efficiency of organic compound in the photoelectrocatalytic reactor was evidently enhanced by the PFC system. The kinetic constant of the photoelectrocatalytic process was found to be ∼1.75 times that of the pure photocatalytic process. Furthermore, the performance of the photoelectrocatalytic reactor was found to increase with the illumination area (of the anode) of PFC and decrease with the external resistor and electrolyte concentration. The category and concentration of the substrate in PFC system were also key factors influencing the efficiency of organic compound removal in the photoelectrocatalytic reactor. The composite system provides a novel way for utilizing of the electrical energy generated from the PFC system and has potential applications for the treatment of various refractory organic pollutants.