La, S, N tri-doped TiO2/nickel foam as efficient photoelectrode for degradation of BTX solution under visible light irradiation

La, S, N tri-doped TiO2 nanoparticles were prepared by facile sol-gel method. Investigation of the optical and photochemical properties of the prepared samples reveals the simultaneous introduction of the metal and nonmetal dopants into TiO2 substantially decreases the recombination rate of charge carriers, as well as increases visible light sensitization of TiO2. The prepared nanoparticles were immobilized onto nickel foam as an efficient substrate. The photoelectrocatalytic reactions were conducted to degrade the benzene, toluene and p-xylene (BTX) aqueous solution under visible light irradiation. After 180 min illumination and 0.8 V applied potential, the highest degradation rate of BTX solution are 83.7%, 71.4% and 62.28% for benzene, toluene and p-xylene, respectively. Under the same experimental condition, the COD analysis shows the mineralization of BTX solution is 51.3 %. The good photoelectrocatalytic performance of the prepared photoanode is attributed to the improved separation of charges caused by the introduction of La, S and N dopants. The recyclability of the prepared photoanode was studied under 6 reaction cycles which revealed the high stability of the photoanode for degradation of BTX solution.