# Nanomaterial Enhanced PVDF Mixed Matrix Membranes for Microfluidic Electrochemical Desalination

## TL;DR

This study explores using nanomaterial-enhanced PVDF membranes for efficient electrochemical desalination of saline water.

## Contribution

The novel contribution is the integration of graphene oxide and carbon nanotubes into PVDF membranes for improved desalination performance.

## Key findings

- PVDF/GO membranes achieved 68% ion removal efficiency, outperforming other configurations.
- The optimized electrode with Nafion and PVDF binders showed the lowest charge-transfer resistance.
- The system reached a salt adsorption capacity of 775.40 mg/g and specific energy consumption of 16.17 kJ/mole.

## Abstract

This work provides a systematic experimental study for the electrochemical desalination of saline water using an electrospun permselective polyvinylidene difluoride (PVDF) membrane. Several nano additives were initially screened during membrane development; however, only the materials that demonstrated stable dispersion, reproducible membrane formation, and consistent electrochemical behaviour, namely graphene oxide (GO) and carbon nanotubes (CNTs) were selected for full analysis in this study. Accordingly, the study focuses on pure PVDF, PVDF/GO, and PVDF/CNTs membranes integrated with an alternating Ag/AgCl electrode system. The silver electrode is prepared by spray-coating of silver nanoparticles on high surface carbon cloth, whereas the AgCl electrode was prepared electrochemically from the Ag electrode using a three-electrode electrochemical cell. The electrochemical behaviour of various modified electrodes (bare carbon cloth, Ag/carbon cloth, Ag/nafion/carbon black/PVDF, and Ag/nafion/carbon cloth) was evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and X-Ray Diffraction (XRD). The electrode prepared using Nafion and PVDF as binders with carbon black as conductive additive exhibited the highest current response and lowest charge-transfer resistance. When coupled with this optimized electrode, the PVDF/GO membrane delivered the best desalination performance, achieving an ion removal efficiency of 68%, a salt adsorption capacity (SAC) of 775.40 mg/g, and a specific energy consumption (SEC) of 16.17 kJ/mole values superior to those reported in the literature.