Synthesis and Characterization of Activated Carbon Co-Mixed Electrospun Titanium Oxide Nanofibers as Flow Electrode in Capacitive Deionization.

Gbenro Folaranmi,Philippe Sistat,Mikhael Bechelany,Francois Zaviska,Myriam Tauk,Marc Cretin

doi:10.3390/ma14226891

Abstract

Flow capacitive deionization is a water desalination technique that uses liquid carbon-based electrodes to recover fresh water from brackish or seawater. This is a potential second-generation water desalination process, however it is limited by parameters such as feed electrode conductivity, interfacial resistance, viscosity, and so on. In this study, titanium oxide nanofibers (TiO2NF) were manufactured using an electrospinning process and then blended with commercial activated carbon (AC) to create a well distributed flow electrode in this study. Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray (EDX) were used to characterize the morphology, crystal structure, and chemical moieties of the as-synthesized composites. Notably, the flow electrode containing 1 wt.% TiO2NF (ACTiO2NF 1 wt.%) had the highest capacitance and the best salt removal rate (0.033 mg/min·cm2) of all the composites. The improvement in cell performance at this ratio indicates that the nanofibers are uniformly distributed over the electrode’s surface, preventing electrode passivation, and nanofiber agglomeration, which could impede ion flow to the electrode’s pores. This research suggests that the physical mixture could be used as a flow electrode in capacitive deionization.

Highlights

Accepted: 9 November 2021One of the growing challenges of the 21st century is the availability of fresh water.Water contamination because of anthropogenic activities such as industrialization, demographic change, and global warming has resulted in a significant increase in demand for safe drinking water
Water desalination technology could help to alleviate this problem by delivering high quality, pure water
The first and most widely used Capacitive deionization (CDI) form involves a pair of porous carbon electrodes separated by a space in which salt water flows as an influent perpendicular to the applied electric field direction [2]

Summary

Introduction

Accepted: 9 November 2021One of the growing challenges of the 21st century is the availability of fresh water.Water contamination because of anthropogenic activities such as industrialization, demographic change, and global warming has resulted in a significant increase in demand for safe drinking water. Water desalination technology could help to alleviate this problem by delivering high quality, pure water Most desalination technologies, such as multiple effect desalination (MED), reverse osmosis (RO), and others, have high capital costs (when considering plant setup) and energy consumption (when considering pre- and post-treatment of water, as in RO), necessitating the development of a new desalination technique [1]. Capacitive deionization (CDI) is a growing desalination technology attracting attention as an energy-efficient, cost-effective, and ecofriendly water treatment technology. A fundamental variation of this basic CDI form emerged with the unfolding of membrane CDI (MCDI) In this architecture, ion exchange membranes were added to the CDI cell configuration to block co-ions from carrying parasitic current, which improves charge efficiency and can increase the charge storage in the electrodes porous structure [3]

Methods

Results

Conclusion