Doping of metal-organic frameworks towards resistive sensing

TL;DR

This paper demonstrates how doping Co-MOF-74 with TCNQ enhances its electrical conductivity, enabling its use in resistive gas and photo-sensing applications by narrowing the optical band gap through charge transfer.

Contribution

It introduces a novel doping method with TCNQ to improve the electrical properties of MOFs for sensing applications.

Findings

Doping narrows the optical band gap to 1.5 eV.

Enhanced electrical conduction enables resistive sensing.

Provides insights into electronic interactions in doped MOFs.

Abstract

Coordination polymerization leads to various metal-organic frameworks (MOFs) in which symmetrical metal nodes exposed to nano voids lead to unique physical properties and chemical functionalities. One of the challenges towards their applications as porous materials is to make MOFs optimally conductive to be used as electronic components. Here, we demonstrate that Co-MOF-74, a honeycomb nano{framework with one{dimensionally arranged cobalt atoms advances its physical properties by accommodating Tetracyanochinodimethan (TCNQ), an acceptor molecule. Strong intermolecular charge transfer narrows the optical band gap down to 1.5 eV of divalent TCNQ and enhances the electrical conduction, which allows the MOF to be utilized for resistive gas- and photo-sensing. Our result provides insight into electronic interactions in doped MOFs and paves the way towards their electronic applications.