Electrically Conductive Diamond Membrane for Electrochemical Separation Processes

TL;DR

This paper presents a novel boron-doped diamond membrane fabricated on quartz fiber filters, offering high electrical conductivity, stability, and self-cleaning capabilities for electrochemical separation in demanding filtration applications.

Contribution

The study introduces a new method to produce a boron-doped diamond membrane with enhanced surface area and stability, suitable for electrochemical filtration and self-cleaning processes.

Findings

High boron doping (> 10^21 cm^-3) achieved in diamond membrane.

Effective removal of redox species via flow-through electrolysis.

Membrane exhibits high stability and self-cleaning ability.

Abstract

Electrochemically switchable selective membranes play an important role in selective filtration processes such as water desalination, industrial waste treatment and hemodialysis. Currently, membranes for these purposes need to be optimized in terms of electrical conductivity and stability against fouling and corrosion. In this paper, we report the fabrication of boron-doped diamond membrane by template diamond growth on quartz fiber filters. The morphology and quality of the diamond coating are characterized via SEM and Raman spectroscopy. The membrane is heavily boron doped (> 1021 cm-3) with > 3 V potential window in aqueous electrolyte. By applying a membrane potential against the electrolyte, redox active species can be removed via flow-through electrolysis. Compared to planar diamond electrodes, the ~250 times surface enlargement provided by such a membrane ensures an effective removal of target chemicals from the input electrolyte. The high stability of diamond enables the membrane to not only work at high membrane bias but also to be self-cleaning via in situ electrochemical oxidation. Therefore, we believe that the diamond membrane presented in this paper will provide a solution to future selective filtration applications especially in extreme conditions.