Energy-free and ultrafast nano pump of water

Abstract

Addressing global freshwater scarcity and energy crises remains a critical challenge to sustainable development. Carbon nanotube (CNT)-based systems for seawater desalination offer a promising solution to these threats. In this study, we demonstrate an active water pump driven by potential energy gradients. Even in the absence of external energy, water molecules traverse the nanotubes, overcoming potential barriers at the tube ends, in stark contrast to energy-driven methods reported in previous literature. The water flux achieved by our system is almost two orders of magnitude higher than in prior studies. Furthermore, we enhance water transport efficiency by wrapping CNTs with polythiophene chains of varying lengths, establishing a continuous potential energy gradient along the nanochannels. This design presents a compelling pathway for developing low-energy, high-efficiency desalination devices, such as artificial purification systems.