Preforming abundant surface cobalt hydroxyl groups on low crystalline flowerlike Co3(Si2O5)2(OH)2 for enhancing catalytic degradation performances with a critical nonradical reaction

Low crystalline flowerlike cobalt silicate hydroxide (Co 3 (Si 2 O 5 ) 2 (OH) 2 , CoSiO x ) is synthesized by a one-pot hydrothermal approach. Abundant highly active Co OH + is preformed on the surface of CoSiO x , while the low crystallinity of CoSiO x leads to the formation of active 1 O 2 caused by the generation of oxygen vacancy in the valence change cycle between Co 2+ and Co 3+ . The optimal CoSiO x with a high specific surface area of 665.2 m 2  g −1 could expose surface Co OH + , thus rapidly activate peroxymonosulfate (PMS) and accelerate catalytic efficiencies. As a result, at least 11 kinds of organic pollutants could be degraded with 33–242% higher efficiencies than reported. In addition to the common SO 4 - and OH, large amounts of active 1 O 2 endow the CoSiO x /PMS system with superb catalytic performances in diverse conditions, suggesting the excellent adaptability for practical usage. This work provides a new protocol to advance the PMS activation process for high-performance cobalt based heterogeneous catalysts.