Novel CuCo₂O₄ Composite Spinel with a Meso-Macroporous Nanosheet Structure for Sulfate Radical Formation and Benzophenone-4 Degradation: Interface Reaction, Degradation Pathway, and DFT Calculation

Abstract

A series of CuCo 2 O 4 composite spinels with an interconnected meso-macroporous nanosheet morphology were synthesized using the hydrothermal method and subsequent calcination treatment to activate peroxymonosulfate (PMS) for benzophenone-4 (BP-4) degradation. As-prepared CuCo 2 O 4 composite spinels, especially CuCo-H3 prepared by adding cetyltrimethylammonium bromide, showed superior reactivity for PMS activation. In a typical reaction, BP-4 (10.0 mg/L) was almost completely degraded in 15 min by the activation of PMS (200.0 mg/L) using CuCo-H3 (100.0 mg/L), with only 9.2 μg/L cobalt leaching detected. Even after being used six times, the performance was not influenced by the lower leaching of ions and surface-absorbed intermediates. The possible interface mechanism of PMS activation by CuCo-H3 was proposed, wherein a unique interconnected meso-macroporous nanosheet structure, strong interactions between copper and cobalt, and cycling of Co(II)/Co(III) and Cu(I)/Cu(II) effectively facilitated PMS activation to generate SO 4•− and • OH, which contributed to BP-4 degradation. Furthermore, combined with intermediates detected by liquid chromatography quadrupole time-of-flight mass spectrometry and density functional theory calculation results, the degradation pathway of BP-4 involving hydroxylation and C−C bond cleavage was proposed.

Activation of peroxymonosulfate by CuCo2O4 nano-particles towards long-lasting removal of atrazine

“…0°, 31.4°, 36.8°, 39°, 44.5°, 55.5°, 59.6°, 65.2°can be indexed to (111), ( 220), ( 311), ( 222), ( 400), ( 422), (511), and (440) of spinel CuCo 2 O 4 (Panayotov & Mehandjiev 1987), indicating the high purity of CuCo 2 O 4 . Moreover, the peak at 35.5°could be indexed to (À111) of CuO (JPCDS 48-1548), similar to the study by Wang et al (2020c). The results were consistent with the removal of sulfamethazine by CuCo 2 O 4 /PMS system reported by Feng et al (2015b).…”

“…To further understand the composition and chemical states of the elements on the surface of CuCo 2 O 4 , the XPS spectra of fresh and reacted CuCo 2 O 4 NPs were acquired. (Wang et al 2020c). In addition, the fitting peaks at 782.03 eV and 797.30 eV were assigned to Co(III) (Kibsgaard et al 2012;Xu et al 2018).…”

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

“…[ 37 ] To verify this hypothesis, phosphate substitution experiments were performed because phosphates can form an inner‐sphere complex with the Lewis sites on AgFeO 2 @CaCO 3 and substitute its surface hydroxyl groups. [ 38 ] As shown in Figure S3a, Supporting Information, the degradation of RhB by the AgFeO 2 @CaCO 3 /PMS system was significantly suppressed with the addition of a low concentration of HPO 4 2− (1 mM), thereby demonstrating the critical role of the hydroxyl groups in AgFeO 2 @CaCO 3 in its PMS activation process.…”

Phosphorus‐Doped CuCo2O4 Oxide with Partial Amorphous Phase as a Robust Electrocatalyst for the Oxygen Evolution Reaction

“…In particular, the spinel AB 2 O 4 (A, B=transition metal) oxides that consist of 3 d transition metals have shown their potential of catalytic performance for OER, such as MnCo 2 O 4 , CoFe 2 O 4 , CoAl 2 O 4 , and NiCo 2 O 4 [19–24] . Here we focus on spinel CuCo 2 O 4 that is widely used in supercapacitors, electrochemical sensors, and oxygen reduction reactions [25–26] . The unique spinel structure should also made it a promising OER catalyst.…”

“…[19][20][21][22][23][24] Here we focus on spinel CuCo 2 O 4 that is widely used in supercapacitors, electrochemical sensors, and oxygen reduction reactions. [25][26] The unique spinel structure should also made it a promising OER catalyst. However, the spinel CuCo 2 O 4 shows low electric conductivity and insufficient exposure of active sites, [27] which greatly hindered its further improvement of electrochemical activity.…”