Preparation of MoO2@nitrogen doped carbon composites for degradation of organic pollutants

The MoO2@nitrogen doped carbon composite (MoO2@CN) was designed via one-step calcination from dopamine, ammonium molybdate, and ammonium bicarbonate. Besides, MoO2@CN was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X - ray photoelectron spectroscopy (XPS), Raman spectroscopy, etc. The MoO2@CN/PMS system could reach 99.2% degradation rate for carbamazepine (CBZ) in 12 min under pH of 6.5 and temperature at 25 degrees C. Moreover, the apparent rate constant (k(obs)) of MoO2@ CN was calculated to be 0.393 min(-1), about 24.0 times higher than that of the commercial MoO2 (0.016 4 min(-1)), which is attributed that MoO2@CN possessed better conductivity and larger specific surface area. MoO2@ CN was capable to degrade CBZ effectively in the pH range of 2.5-10.5, and also exhibited effective degradation performance for most dyes, phenolic compounds, antibiotics, and other pollutants. In addition, the total organic carbon (TOC) degradation rate of CBZ was as high as 74.0% within 60 min in the MoO2@ CN/PMS system. Electron paramagnetic resonance (EPR) spectroscopy and quenching tests were applied to verify that SO4 center dot- and center dot OH played a major role in the MoO2@ CN/PMS system. Interestingly, the degradation performance of CBZ was significantly enhanced with high kobs