A coupling method introducing persulfate (PS) into a photocatalytic fuel cell (PFC) was investigated to improve the decoloration of methyl orange (MO) and simultaneous electricity production. The TiO2 nanotube arrays (TNAs) were fabricated successfully on the titanium sheet as the photoanode, which was confirmed by the characterizations of X-ray diffraction and scanning electron microscopy. Due to the characteristics of inorganic sacrificial agent and strong oxidant for PS, the proposed PFC/PS system could improve the photocatalytic reaction and extend the range of active species reaction from the solid electrodes surface to the total liquid phase through the formation of sulfate radical (SO4 center dot-) and hydroxyl radical (HO center dot) for MO removal. Hence, PFC/PS exhibited remarkable cell performance, increasing the MO decomposition by 40.36% and electricity generation by 44.97% relative to the PFC system without adding PS. Besides, the pollutant removal ability of the PFC/PS system was systematically assessed at different operation parameters, such as PS concentration, initial MO concentration, initial pH, and UV light intensity. Furthermore, the underlying mechanism of MO elimination was elucidated by the radicals quenching tests and hydrogen peroxide (H2O2) quantitative determination, and these results confirmed that the formation of reactive species, including SO4 center dot-, HO center dot, H2O2 and even photogenerated holes, were responsibility for contaminant abatement in the PFC/PS system. (c) 2018 Elsevier Ltd. All rights reserved.