Formation of CaCO₃ deposits on OMS‐2 surface to synergistically promote peroxymonosulfate activation and organic dyes degradation

Abstract

The development of green and efficient catalysts for peroxymonosulfate (PMS) activation and organic pollutants degradation has received widespread attention. In this study, the hybrid CaCO 3 /OMS-2 catalysts were prepared by a simple precipitation approach and characterized by X-ray powder diffraction, N 2 adsorption-desorption, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and cyclic voltammetry. It was found that deposition of CaCO 3 on OMS-2 surface can weaken the Mn-O bond by formation of Ca-O-Mn bond. The interactions between CaCO 3 and OMS-2 significantly enhanced Acid Orange 7 degradation in the presence of PMS with a pseudo-first-order kinetic constant of 0.21 min −1 , which was much higher than those of OMS-2 (0.026 min −1 ) and CaCO 3 (0.021 min −1 ). The CaCO 3 / OMS catalysts were also much more efficient than other reported OMS-2 hybrid catalysts, and could be performed over a wide solution pH and for other organic dyes degradation. Sulfate and hydroxyl radicals were formed from the oxidation of low valent manganese species by PMS as the active species in the system. This study can provide a simple method for the design of efficient manganese-based hybrids for wastewater remediation via PMS activation.

Facile Synthesis of AgFeO2‐Decorated CaCO3 with Enhanced Catalytic Activity in Activation of Peroxymonosulfate for Efficient Degradation of Organic Pollutants

“…Second, according to the previous literature, bare CaCO 3 can activate PMS to degrade organic pollutants, and it may contribute to the overall catalytic activity of AgFeO 2 @CaCO 3 . [ 34 ] As shown in Figure 3b, ≈20.5% of the RhB was removed after 60 min by CaCO 3 in the presence of PMS. Last, studies have demonstrated that hydroxyl groups in catalysts can enhance their catalytic activity in activating PMS.…”

Self‐Assembly of Hydroxyl Metal–Organic Polyhedra and Polymer into Cu‐Based Hollow Spheres for Product‐Selective CO2 Electroreduction

“…[30][31][32] The Ca 2p spectrum shows two peaks at 350.1 and 346.3 eV, revealing the presence of CaCO 3 (Figure S8b, Supporting Information). [33] Furthermore, the C 1s spectrum displays two peaks at 284.6 eV (C─C) and 289 eV (O─C═O) (Figure S8c, Supporting Information). [34] The O 1s spectrum can be deconvoluted into a strong peak of C ¼ O at 530.8 eV and a relatively weak peak of Cu─O at 529.3 eV (Figure S8d, Supporting Information).…”