Facile constructing ZrO2 nanoparticles equipped with high conductivity carbon networks as pseudocapacitive anodes for removing phosphorus

Abstract

Phosphorus pollution can seriously disrupt water quality and endanger ecosystem sustainability. Nonetheless, a few typical methods have been employed to remove phosphorus, but there are still challenges in controlling phosphorus from sewage. Capacitive deionization (CDI) displays the merits of having eco-friendliness and low energy consumption when capturing phosphorus. However, traditional carbon electrodes often suffer from the limitation that phosphorus uptake sites are insufficient. Herein, a novel ZrO₂ nanoparticle equipped with a highly conductive carbon network (NZrC) was fabricated by a facile co-pyrolysis process. Na₂EDTA can provide additional carbon backbones, N species, and metal chelation sites. Zr-MOF was applied as the ZrO₂ precursor with abundant phosphorus trapping sites. The results suggested that Na₂EDTA favors improving the ZrO₂ dispersion, mesoporous channel formation, and pseudocapacitive behavior. NZrC-21 at 1.2 V displays low energy consumption and the optimal phosphorus uptake capacity of 10.99 mg P/g because of its rich mesoporous structure, abundant pyrrolic-N, graphitic-N, and ZrO₂ active sites, and outstanding electrochemical properties. Furthermore, several key parameters were investigated for their effect on phosphorus removal performance. The mechanism revealed that hydrogen bonds, ligand exchange, and electrostatic attraction are the main uptake processes. This work presents a novel perspective for the facile construction and utilization of metal oxide nanoparticles equipped with a highly conductive carbon network for removing phosphorus.