Structure-dependent catalysis of Co3O4 crystals in persulfate activation via nonradical pathway

ZnO–Co3O4/N–C Cage Derived from the Hollow Zn/Co ZIF for Enhanced Degradation of Bisphenol A with Persulfate

“…Metal organic frameworks (MOFs) are a kind of interesting and multifunctional hybrid materials. − Among various MOFs, zeolitic imidazolate frameworks (ZIFs) such as ZIF-67 synthesized using cobalt ions and 2-methylimidazole (2-MI) have been demonstrated to be effective materials for gas separation and catalysis. , Especially, the ZIF-67 crystals were also good precursors for synthesizing metallic cobalt/carbon (Co/C) composites and cobalt oxides such as Co 3 O 4 , which have been widely adopted as catalysts in environment and energy catalysis. − However, it was worth mentioning that the direct calcination of ZIF-67 can lead to the formation of Co/C composites and Co 3 O 4 powders with relatively large particles. , In addition to the application in electrocatalysis, it has been evidenced that the Co 3 O 4 nanocrystals could be good candidates as catalysts for the oxidative degradation of refractory organic pollutants such as bisphenol A (BPA) and nitrophenol in the presence of oxidizing agents. − Generally, the oxidation of such compounds known as advanced oxidation processes required oxidizing agents such as persulfate and peroxymonosulfate, which should be activated by heat, photolysis, microwaves, electron beam, and chemical processes by transition metals. , …”

A porous graphitic biochar wrapped Co9S8 core–shell composite enables pH-universal activation of peroxymonosulfate for highly efficient and rapid antibiotics degradation

“…In addition, BC had a peak at 530.0 eV, referring to the binding of CO. Co 9 S 8 also had a peak at 529.7 eV, corresponding to surface lattice oxygen (O L ). 12,22 However, only surface O A was detected for Co 9 S 8 @N–O–BC-800-(0.1 : 1) attributed to the adsorbed and dissociated oxygen species (O 2− , O 2 − , OH − or O − ) and CoOH + , 12 which were the most active oxygen species, playing a critical role in the oxidation reaction. The N 1s spectrum was divided into two peaks at 399.62/399.97 and 406.87/409.36 eV representing pyrrolic-N and oxidized-N.…”

“…Co 9 S 8 also had a peak at 529.7 eV, corresponding to surface lattice oxygen (O L ). 12,22 However, only surface O A was detected for Co 9 S 8 @N-O-BC-800-(0.1 : 1) attributed to the adsorbed and dissociated oxygen species Environmental Science: Nano Paper addition, the satellite peaks of Co(II) corresponded to 787.1 and 802.9 eV. 25,26…”

“…46 In addition, 1 O 2 could also be generated by the self-decomposition of PMS (eqn (27)) and the reaction between PMS and the carbonyl group of Co 9 S 8 @N-O-BC*. Then, according to research, 12 Co(II) could be used as a Lewis site and coupled with dissociative adsorption of H 2 O to generate CoOH + on the Co 9 S 8 @N-O-BC* surface. When PMS was added, CoOH + could react with PMS through H-bonding to improve the activation.…”

“…Among all kinds of catalysts, various Co-based catalysts have been explored and exhibited the best catalytic performance in activation of PS. For example, Yang et al 12 successfully synthesized several different Co 3 O 4 crystals, which almost completely removed 30 mg L −1 orange G in 10 min. Nonetheless, Co-based catalysts still face problems such as uncontrollable free radical generation and self-quenching, which reduce the utilization rate of oxidants and the degradation efficiency of pollutants as well as limiting the scope of utilization.…”