Development of a novel 2D Ni-MOF derived NiO@C nanosheet arrays modified Ti/TiO2NTs/PbO2 electrode for efficient electrochemical degradation of salicylic acid wastewater

[Display omitted] •A novel 2D Ni-MOF derived NiO@C nanosheet arrays modified Ti/TiO2NTs/PbO2 electrode is prepared.•The Ti/TiO2NTs/NiO@C/PbO2 electrode displays superb stability and electro-catalytic oxidation ability.•The Ti/TiO2NTs/NiO@C/PbO2 electrode showed high performance for SA pretreatment.•The possible degradation pathways of SA was speculated by UV and LC-MS. To overcome the shortcoming of Ti/PbO2, construction of novel Ti/TiO2NTs/NiO@C/PbO2 electrode by introducing a 2D Ni-MOF derived NiO@C nanosheet arrays interlayer onto the Ti/TiO2NTs matrix via hydrothermal and carbonization process. Benefiting from the synergistic effect and unique 2D nanosheet array structure, the Ti/TiO2NTs/NiO@C/PbO2 electrode exhibited excellent electrochemical activity, higher ·OH radicals generating ability on the surface of the electrode and excellent electrocatalytic degradation efficiency. Compared with Ti/TiO2NTs, the conductivity of the Ti/TiO2NTs/NiO@C electrode exhibited significantly enhanced, which is due to introducing a 2D Ni-MOF derived NiO@C nanosheet arrays. The oxidative removal of salicylic acid (SA) in an aqueous medium has been investigated by electrooxidation processes using three different electrodes. The influence of diverse electrodes and operating conditions on the electrocatalytic degradation of SA was also systematically studied. Additionally, the possible electrocatalytic degradation mechanism of SA was proposed using Ti/TiO2NTs/NiO@C/PbO2 electrode, and a feasible degradation pathway of SA was deduced by employing ultraviolet–visible spectrophotometer and liquid chromatograph/mass spectrometer (LC-MS).