In situ nitrogen doping of lithium cobalt oxide via rhodamine B degradation offers the reused material a better activity

Recycling the wasted lithium-ion batteries for environmental catalysis is promising to control pollution since the electrode materials usually contain metal oxides showing good catalytic activities. Herein, the LiCoO 2 was synthesized and used to treat the simulated dye wastewater. In order to cope with the practical water pollution, the effects of rhodamine B (RhB) concentration, concomitant ions, solution pH, air blowing and reaction temperature were systematically investigated. The most important finding of this study is the in situ nitrogenization of the LiCoO 2 via RhB degradation, which offered the reused material a much better activity than the fresh one due to the formation of more defect oxygen species, and the activity of the reused LiCoO 2 became better and better with cycling runs. At the third time of usage, ~90% of RhB could be removed under the conditions of 0.2 g of catalyst, 50 mL of 5 mg·L −1 RhB solution and 30 °C whereas only ~60% of RhB was degraded over the fresh sample. The results of this study will also have scientific significance for the development of nitrogen-doped LiCoO 2 in other application fields.