# Designing an All-Carbon Membrane for Water Desalination

## TL;DR

This paper presents the design of an all-carbon membrane combining layered carbon nanostructures for efficient water desalination, offering enhanced durability, chemical resistance, and ion rejection capabilities.

## Contribution

It introduces a novel layered all-carbon membrane structure and provides atomic-level insights into water permeation and ion rejection mechanisms.

## Key findings

- High mechanical strength and chemical resilience of the membrane.
- Selective rejection of Na+ ions demonstrated through atomic simulations.
- Structural stability of the membrane in desalination conditions.

## Abstract

We design an all-carbon membrane for the filtration and desalination of water. A unique layered assembly of carbon nanostructures including graphite oxide (GO), buckypaper consisting of carbon nanotubes, and a strong carbon fabric provides high mechanical strength and thermal stability, resilience to harsh chemical cleaning agents and electrical conductivity, thus addressing major shortcomings of commercial reverse osmosis membranes. We use ab initio density functional theory calculations to obtain atomic-level insight into the permeation of water molecules in-between GO layers and across in-layer vacancy defects. Our calculations elucidate the reason for selective rejection of solvated Na$^+$ ions in an optimized GO membrane that is structurally stabilized in a sandwich arrangement in-between layers of buckypaper, which are protected on both sides by strong carbon fabric layers.