Rapid one-pot microwave-hydrothermal synthesis of OMS-2 and full-solar-spectrum photocatalytic performance for high phenol concentration

A new rapid and simple synthesis method of cryptomelane-type octahedral molecular sieve (OMS-2) was proposed, which only required KMnO4 and H2SO4 as reactants and a controlled microwave hydrothermal process. The crystallinity and particle size of OMS-2 were found to gradually increase with the synthesis temperature and time, while the specific surface area decreased. Moreover, the synthesis of pure OMS-2 only required about 5 min at 180 degrees C, which is a lower synthesis time than those of previously reported methods. For the high concentration (100 mg/L) of phenol degradation under full-solar-spectrum irradiation, the removal rates of phenol were all in the range of 67%-73%, but the removal rates of total organic carbon were between similar to 40% and similar to 60%. This indicates that the synthesized OMS-2 had a similar high photocatalytic performance for phenol in a wide temperature and time range. And it can be suitable for industrial application. (C) 2019 Elsevier B.V. All rights reserved.