Abstract
The urgent removal of Cd, Co, and Ni from nitrate and sulfate is essential to mitigate the potential risk of chemical pollution from large volumes of industrial wastewater. In this study, these metal ions were rapidly recovered through applying voltage on nitrate and sulfate, utilizing laser-induced graphene/polyimide (LIG/PI) film as the electrode. Following the application of external voltage, both the pH value and conductivity of the solution undergo changes. Compared to Co(2+) and Ni(2+), Cd(2+) exhibits a lower standard electrode potential and stronger reducibility. Consequently, in both nitrate and sulfate solutions, the reaction sequence follows the order of Cd(2+) > Co(2+) > Ni(2+), with the corresponding electrode adsorption quantities in the order of Cd(2+) > Co(2+) ~ Ni(2+). Additionally, using the recovered Co(OH)(2) as the raw material, a LiCoO(2) composite was prepared. The assembled battery with this composite exhibited a specific capacity of 122.8 mAh g(-1), meeting practical application requirements. This research has significance for fostering green development.