Efficient degradation of organic dye using Ni-MOF derived NiCo-LDH as peroxymonosulfate activator.

Nickel-based metal-organic framework (Ni-MOF) was employed as a sacrificial template for the preparation of nickel-cobalt layered double hydroxide (NiCo-LDH) under different hydrolysis time. The template etching rate varied at different hydrolysis time, resulting in variations of the structural and morphology of NiCo-LDHs. The NiCo-LDH/10 sample showed a large specific surface area and the well-oriented larger dimension of thinner sheets due to the sufficient in-situ etching of the Ni-MOF template. The NiCo-LDH/10 was an excellent heterogeneous catalyst to activate peroxymonosulfate (PMS) for highly efficient Reactive Red-120 dye degradation. The results exhibited that the degradation efficiency of the NiCo-LDH/10-PMS catalyst was 89% for RR-120 dye within 10 min in the presence of the PMS system, which is higher than other NiCo-LDHs. Moreover, the other influencing factors such as PMS concentration, catalyst dosage, initial pH were also investigated towards degradation. The radical quenching measurement proved that the sulfate (SO) and hydroxyl (OH) had been indicated as the primary radicals. Besides, the NiCo-LDH/10-PMS catalyst showed excellent reusability even after five consecutive cycles (83.6% of the degradation efficiency). This work offer insight study on the construction of controlled morphology NiCo-LDH heterogeneous structure for high-efficiency PMS activation.