Well-defined bimetal oxides derived from Prussian blue analogues with regulable active sites for phosphate removal

Two well-defined CoFe bimetal oxides are prepared from Prussian blue analogues (PBAs) as precursors with designable structures, which are further explored for phosphate removal. A speed-controlled coordination strategy is used to fabricate two CoFe PBA microcrystals with different morphologies, then two regular CoFe oxides are obtained via an intermediate-temperature calcination. CoFeS, a slow-speed coordination product with truncated microcube structure, contains less coordinated water and Fe3+ in its framework, but can create more mesopores and Fe3+ in its oxidative product of CoFeST300. CoFeST300 has been demonstrated to have higher adsorption capacity and affinity for phosphate adsorption compared to that of the fast-speed coordination product, due to its more Fe3+ as effective adsorption sites via ligand exchange. Besides, the inner-sphere complexation mechanism makes CoFeST300 high selectivity for phosphate removal compared to other co-existing anions. The application performance of CoFeST300 is examined by multiple continuous treatment of actual sewage, and the result of all effluent & nbsp; concentrations below 0.5 mg P/L verifies a promising potential of the fabricated adsorbent for phosphorus removal. Thus, design or regulation of the precursors is an efficiency method to fabricate an ideal metal oxide for phosphate adsorption. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

Two well-defined CoFe bimetal oxides were prepared and explored for phosphate removal. Among them, CoFeST300 exhibited higher adsorption capacity, affinity, and selectivity for phosphate compared to other products. Multiple treatments of actual sewage confirmed the promising potential of the fabricated adsorbent for phosphorus removal.