Rational Regulation of Co–N–C Coordination for High-Efficiency Generation of ¹O₂ toward Nearly 100% Selective Degradation of Organic Pollutants

Abstract

Single oxygen-based advanced oxidation processes (1O2-AOPs) exhibit great prospects in selective degradation of organic pollutants. However, efficient production of 1O2 via tailored design of catalysts to achieve selective oxidation of contaminants remains challenging. Herein, we develop a simple strategy to regulate the components and coordination of Co–N–C catalysts at the atomic level by adjusting the Zn/Co ratio of bimetallic zeolitic imidazolate frameworks (Zn x Co1-ZIFs). Zn4Co1–C demonstrates 98% selective removal of phenol in the mixed phenol/benzoic acid (phenol/BA) solutions. Density functional theory calculations and experiments reveal that more active CoN4 sites are generated in Zn4Co1–C, which are beneficial to peroxymonosulfate activation to generate 1O2. Furthermore, the correlation between the origin of selectivity and well-defined catalysts is systematically investigated by the electron paramagnetic resonance test and quenching experiments. This work may provide novel insights into selective removal of target pollutants in a complicated water matrix.

Integrating energy-environmental functions into multifaceted lignocellulose valorization: high-performance supercapacitors and antibiotic decomposition

“…36 The appearance of (111) and (220) planes with the standard Co pattern at 45°and 51°, respectively, potentially suggests a face-centered cubic Fm3m structure of Co nanoclusters with 5.668 Å lattice parameters. 34,37 These results confirmed the preferential growth of Co nanoclusters along the (111) direction to anchor on the N-C biochar support. As mentioned above, the intensity ratio of the D to G bands functions as a direct indicator of the level of atomic ordering of carbonaceous materials, which would gradually increase with an increase in the relative degree of graphitization in amorphous biochar frameworks.…”

Double-Confined Ultrafine Cobalt Clusters for Efficient Peroxide Activation

“…The optimized models of Co/NC@mSiO 2 (Figure S19) and Co/mSiO 2 (Figure S20) were proposed according to the previous XAFS and XPS results. Generally, PMS activation on the surface of catalysts consisted of two continuous steps: the adsorption toward O sites of PMS and then activation for ROS production . First, we examined the adsorption of PMS on the catalyst surface.…”

“…The N 1s spectrum of Co/ NC@mSiO 2 (Figure 2j) showed characteristic peaks of pyridinic N (or Co−N), pyrrolic N, graphitic N, and Noxide centered at 399.1, 400.4, 401.6, and 403.0 eV, respectively. 31 In contrast, no signals for the N element were detected in Co/mSiO 2 , further indicating that the presence of CTAB had an important impact on the formation of NC dots. The obvious changes in the C 1s and N 1s spectra proved the improved electronic structures of Co/NC@mSiO 2 due to the SMSI effect.…”

MOF Derived Carbon Nanofibers Substrate Supported Polymeric Ultrafiltration Membrane for Efficient Removal of Trace Organic Contaminants

“…However, when TBA with the molar ratio of TBA/PMS = 1000 was added, the k″ decreased to 0.0523 min –1 , indicating that · OH made little contribution to the degradation of BPA, while SO 4 ·– played a dominant role. In addition, l -histidine (L-HIS) and potassium dichromate (K 2 Cr 2 O 7 ) were selected as scavengers to verify the contribution of 1 O 2 and e – in the BPA degradation process. − In order to eliminate the interference of SO 4 ·– and · OH, MeOH was also added into the degradation system. The results indicated that the contributions of 1 O 2 and e – to BPA degradation were limited.…”