Synthesis and characterization of conductive polymer coated graphitic carbon nitride embedded sulfonated poly (ether ether ketone) membranes for direct methanol fuel cell applications

Abstract

Direct methanol fuel cell (DMFC) is a sustainable energy conversion device that is known for its advantages in terms of portability as well as can be stored and transported safely. Functionalized nanostructured materials have been used in proton exchange membrane (PEM) for DMFC applications to enhance the proton conductivity and suppress the methanol permeability. In this study, conductive polyaniline deposited oxidized graphitic carbon nitride (PANI-O-g-C 3 N 4 ) was incorporated in sulfonated poly (ether ether ketone) (SPEEK) membrane for DMFC applications. The performances of graphitic carbon nitride (g-C 3 N 4 ) and oxidized graphitic carbon nitride (O-g-C 3 N 4 ) on SPEEK PEM were also assessed and compared. The morphological and X-ray diffraction analysis indicated that the structure and crystallinity were altered with the deposition of PANI on g-C 3 N 4 . The scanning electron microscopy and topography analysis revealed that the existence of g-C 3 N 4 and functionalized g-C 3 N 4 were clearly seen on the surface of the SPEEK membrane. Water uptake capacity and ion exchange capacity were significantly improved in the functionalized g-C 3 N 4 -modified SPEEK membrane (O-g-C 3 N 4 /SPEEK and PANI-O-g-C 3 N 4 / SPEEK). The lower methanol permeability and higher proton conductivity of 3.71 Â 10 À7 cm À2 S À1 and 5.34 Â 10 À3 S cm À1 were recorded by 0.1 wt% PANI-O-g-C 3 N 4 incorporated SPEEK membrane. Functionalized g-C 3 N 4modified SPEEK membrane also exhibited higher oxidative stability. The performance of the PANI-O-g-C 3 N 4 incorporated SPEEK membrane in DMFC application highlights its potential as a superior nanofiller for the modification of PEM.

Progress of g‐C 3 N 4 and carbon‐based material composite in fuel cell application

“…At higher loading concentrations, conductive O-g-C 3 N 4 covered polymers can be employed as excellent methanol barrier fillers in low-cost PEM manufacturing for portable DMFC applications. 154 The VRB system's SPEEK/g-C 3 N 4 hybrid membrane was successfully manufactured. The coupled g-C 3 N 4 nanosheets successfully control ion selectivity, vanadium ion transport, and hybrid membrane structural stability by controlling the created interface interaction.…”

“…PANI deposited O‐g‐C 3 N 4 was produced via in situ polymerization as well as integrated efficiently in SPEEK matrix for DMFC applications by Yogarathinam et al 154 When compared to pure SPEEK membranes, nanocomposite membranes have decreased methanol permeability. The PANI‐O‐g‐C 3 N 4 /SPEEK‐2 membrane with 0.1% by weight had a reduced methanol permeability of 3.71 × 10 −7 cm −2 S −1 .…”

“…Under DMFC conditions, the 0.1% by weight‐loaded PANI‐O‐ g‐C 3 N 4 /SPEEK membrane had greater electrochemical selectivity and a substantial power density. At higher loading concentrations, conductive O‐ g‐C 3 N 4 covered polymers can be employed as excellent methanol barrier fillers in low‐cost PEM manufacturing for portable DMFC applications 154 …”

A review on sulfonated poly (ether ether ketone) based‐membrane in direct borohydride fuel cell applications

“…This is owing to g‐inherent C 3 N 4 's mechanical stability and the nanoparticles' good interface contact with the SPEEK matrix. PANI deposited O‐g‐C 3 N 4 was produced in situ and integrated in the SPEEK matrix for DMFC application by Yogarathinam et al 105 The percentage of water uptake and IEC of nanocomposite membranes was increased in g‐C 3 N 4 and g‐C 3 N 4 ‐activated SPEEK‐modified membranes, according to their findings. Because of the existence of hydrophilic groups, this is the case.…”

“…Furthermore, g-C 3 N 4 and g-C 3 N 4 -activated modified SPEEK membranes boost proton conductivity. 105 Gang et al 28 discovered a composite membrane made of g-C 3 N 4 nanocomposite sheets integrated into a SPEEK matrix. The results demonstrated an enhanced in conductivities than SPEEK control membrane.…”