Efficient activation of peroxymonosulfate by CoCuAl-LDH nanosheets for the degradation of RhB

We prepared a series of copper-containing or non-copper-containing CoAl-Layered Double Hydroxide (LDH) by hydrothermal method, and used it to activate peroxymonosulfate (PMS) to degrade Rhodamine B (RhB). The research structure showed that the addition of copper could improve the activation efficiency of LDH and make the degradation rate of RhB faster. The effect was the best when the ratio of copper to cobalt reached 1:19. Under the combined action of 30 mg PMS and 25 mg CoCuAl-LDH, 98 % of the organic dye was effectively removed from a Rhodamine B (RhB) solution with a concentration of 100 mg/L. Electrochemical Impedance Spectroscopy (EIS) and linear sweep voltammetry (LSV) tests showed that adding copper could effectively improve the electron transfer rate of LDH, thereby improving the catalytic degradation efficiency. XPS and free radical quenching experiments also showed that cobalt ions participated in the reaction, and the generated singlet oxygen (¹O₂) as the main free radical presided over the degradation of RhB. In this study, we synthesized CoCuAl-LDH nanosheets through a facile method and demonstrated their superior electrochemical properties compared to conventional CoAl-LDH.