Novel NiCoMnO4 thermocatalyst for low-temperature catalytic degradation of methylene blue

Abstract

A novel NiCoMnO4 composite thermocatalyst was prepared through a simple chemical co-precipitation method and used for low-temperature catalytic degradation of methylene blue (MB). The samples were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), Brunauer–Emmett–Teller (BET) method, UV–vis spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FT-IR) and gas chromatography–mass spectrometry (GC–MS). Experiments show that the thermocatalytic activity of NiCoMnO4 complex oxide is excellent and it can lead to acute thermal degradation of methylene blue. The conjugated structure and phenyl rings of the methylene blue molecule were destroyed or even broken down into small pieces. Sintering temperature and reaction temperature are found to have significant effects on the thermocatalytic activity. NiCoMnO4 calcined at 700°C, reaction temperature at 50°C, the total methylene blue removal ratio arrives at 75.9% with the powders dosage 375mg/L after 10h and 92.3% after 40h. And the degradation efficiency could achieve higher with the further increase of reaction time.