Fig. 6: Reactive separations using PANI-Co3O4/CNT composites.
From: Coupling nitrate capture with ammonia production through bifunctional redox-electrodes
a Nitrate uptake capacity using PANI/CNT and PANI-Co3O4/CNT composites at various Co3O4 loadings. Electrosorption was carried out in 5 mM NaNO3 + 5 mM NaCl at +0.4 V vs Ag/AgCl for 0.5 h. Within the experimental range, the existence of Co3O4 did not bring about any decrease in nitrate electrosorption. b Percentage of nitrogen species recovered in the form of nitrate, nitrite, and ammonium after release into 0.1 M NaCl for 1 h at various electrode potentials. Before release, electrosorption was carried out in 5 mM NaNO3 + 5 mM NaCl at +0.4 V vs Ag/AgCl for 0.5 h. c Nitrate uptake capacity (left y axis) and percentage of nitrogen species recovered (right y axis) after one full cycle of electrosorption and regeneration using CNT, PANI/CNT, and PANI-Co3O4/CNT electrodes. Electrosorption was carried out in 5 mM NaNO3 + 5 mM NaCl at +0.4 V vs Ag/AgCl for 0.5 h, and regeneration was performed in 0.1 M NaCl at −1.4 V vs Ag/AgCl for 1 h. d 1H-NMR spectra for the regeneration electrolytes after a full cycle of electrosorption (+0.4 V vs Ag/AgCl) and release (−1.4 V vs Ag/AgCl). a.u., arbitrary units. Error bars indicate the standard error of the mean (n = 2). See “Methods” for experimental details.
