Carbon Nanoarchitectonics with Bi Nanoparticle Encapsulation for Improved Electrochemical Deionization Performance

Abstract

Electrochemical deionization (EDI) is hopefully the next generation of water treatment technology. Bismuth (Bi) is a promising anode material for EDI, due to its high capacity and selectivity toward Cl–, but the large volume expansion and severe pulverization aggressively attenuated the EDI cycling performance of Bi electrodes. Herein, carbon-layer-encapsulated nano-Bi composites (Bi@C) were prepared by a simple pyrolysis method using a Bi-based metal–organic framework as a precursor. Bi nanoparticles are uniformly coated within the carbon layer, in which the Bi–O–C bond enhances the interaction between Bi and C. Such a structure effectively relieves the stress caused by volume expansion by the encapsulation effect of the carbon layer. Moreover, the introduction of a carbon skeleton provides a conductive network. As a consequence, the Bi@C composite delivered excellent electrochemical performance with a capacity of 537.6 F g–1 at 1 mV s–1. The Cl– removal capacity was up to 133.5 mg g–1 at 20 mA g–1 in 500 mg L–1 NaCl solution. After 100 cycles, the Bi@C electrode still maintains 71.8% of its initial capacity, which is much higher than the 26.3% of the pure Bi electrode. This study provides a promising strategy for improving EDI electrode materials.

Bismuth Nanoparticle-Embedded Carbon Microrod for High-Rate Electrochemical Magnesium Storage

“…The C 1s spectra in Figures d and S2 show a main CC peak, coexisting with three weak peaks of C–O, CO, and O–CO. The existence of the CC bond improves the conductivity of the Bi⊂CM composites . The Bi 4f spectra exhibit two peaks at binding energies of 159.3 (Bi 4f 7/2 ) and 164.6 eV (Bi 4f 5/2 ), which are indexed to Bi 2 O 3 that is oxidized from Bi metal in the composites .…”

“…The existence of the C�C bond improves the conductivity of the Bi⊂CM composites. 32 The Bi 4f spectra exhibit two peaks at binding energies of 159.3 (Bi 4f 7/2 ) and 164.6 eV (Bi 4f 5/2 ), which are indexed to Bi 2 O 3 that is oxidized from Bi metal in the composites. 25 This was also reflected by the Bi−O−Bi bond in the O 1s spectra, in which the peak at 532.3 eV could be assigned to the Bi−O−C bond in the Bi⊂CM composites.…”

Enhanced Pseudo-Capacitance Process in Nanoarchitectural Layered Double Hydroxide Nanoarrays Hollow Nanocages for Improved Capacitive Deionization Performance

“…Capacitive deionization (CDI) is a robust process for producing clean water from brackish water with low energy input and high efficiency. − The most important part of CDI is the electrode, which determines the desalination performance. − In recent years, CDI faradic electrodes emerged as a hot topic due to their strong deionization ability. − While several materials have been explored for the selective removal of sodium (Na + ) ions, faradic materials for the removal of chloride (Cl – ) ions are limited . Materials like Ag and Bi, − which are often used for Cl – capture, face challenges like high costs and poor cycle performance. , …”

Porous NaTi2(PO4)3 Nanoparticles Encapsulated in Nitrogen-Doped Carbon Matrix for High-Performance Capacitive Deionization

“…Besides, co-ion expulsion often occurs, leading to a significant decrease in charge efficiency and an increase in energy consumption. To overcome the limitations, Faraday electrode materials based on reversible redox reactions or ion intercalation effects are studied . It has been shown that the Faraday electrode materials selectively adsorb cations or anions, avoiding the co-ion expulsion effect and increasing desalination charging efficiency .…”