Universal Approach for Electronically Tuned Transition-Metal-Doped Graphitic Carbon Nitride as a Conductive Electrode Material for Highly Efficient Oxygen Reduction Reaction

Abstract

The rational design of electronically tuned transition-metal-doped conductive carbon nanostructures has emerged as a potential substitution of a platinum-group-metal (PGM)-free electrocatalyst for oxygen reduction reaction (ORR). We report here a universal strategy using a one-step thermal polymerization reaction for transition-metal-doped graphitic carbon nitride (g-C3N4) without any conductive carbon support as a highly efficient ORR electrocatalyst. X-ray absorption spectroscopy evidences the presence of Fe–Nx active sites with a possible three-coordinated Fe atom with N atoms. The as-prepared Fe-g-C3N4 with improved surface area, graphitic nature, and conductive carbon framework exhibits a superior electrochemical performance toward ORR activity in an alkaline medium. Interestingly, it displays a 0.88 V (vs reversible hydrogen electrode, RHE) half-wave potential (E 1/2) with a four-electron-transfer pathway and excellent stability outperforming platinum/carbon (Pt/C) in an alkaline medium. More impressively, when the Fe-g-C3N4 catalyst is used as a cathode material in a zinc–air battery, it presents a higher peak power density (148 mW cm–2) than Pt/C (133 mW cm–2), which further established the importance of the low-cost material synthesis approach toward the development of an earth-abundant PGM-free catalyst for fuel-cell and air battery fabrication.

Polymer‐Assisted Electrophoretic Synthesis of N‐Doped Graphene‐Polypyrrole Demonstrating Oxygen Reduction with Excellent Methanol Crossover Impact and Durability

“…Powder X‐ray diffraction (XRD) analysis was performed to understand the crystalline nature of the as‐synthesized materials and any change in its graphitic domain. As depicted in Figure a, G‐PPy shows a broad peak at 25° corresponding to a d ‐spacing of 3.55 Å, which is indexed as the (0 0 2) plane of the graphitic carbon . In contrast, the peak at 26.3° with the corresponding d ‐spacing of 3.38 Å in NG‐PPy became sharper and slightly shifted indicating that more crystallinity and distortion was introduced owing to the inclusion of nitrogen in the graphene matrix.…”

“…The electrochemical oxygen reduction reaction (ORR) in alkaline and direct methanol (CH 3 OH) fuel cells as well as metal–air batteries mainly depends on the nature and performance of the cathode catalysts . However, the sluggish reaction kinetics of ORR is the main technological bottleneck for commercialization of the catalyst .…”

Development of ciprofloxacin sensor using iron-doped graphitic carbon nitride as transducer matrix: Analysis of ciprofloxacin in blood samples

“…The micrographs were obtained at 3,000 magnifications by an expediting voltage of 5.0 kV LED. The sheets-like morphology evidences a greater surface area for the catalytic reactions between target and transducer interface [38].…”

Element-doped graphitic carbon nitride: confirmation of doped elements and applications

“…Please do not adjust margins Please do not adjust margins X-ray absorption spectroscopy (XAS) measurements, including X-ray absorption near edge structure (XANES), near-edge X-ray absorption fine structure (NEXAFS) and extended X-ray absorption fine structure (EXAFS), can be used to characterize the chemical states of doped elements in g-CN-based materials. 60,85,114,174,175 The bond types of doped elements can be easily distinguished according to EXAFS peaks. For instance, as shown in the Fourier-transformed EXAFS (FT-EXAFS) spectra (Fig.…”