Phosphorus-Doped Graphene Electrocatalysts for Oxygen Reduction Reaction

Synergistic Effects of Carbon Vacancies in Conjunction with Phosphorus Dopant across Bilayer Graphene for the Enhanced Hydrogen Evolution Reaction

Bilayer graphene (BLG) exhibits distinct physical properties under external influences, such as torsion and structural defects, setting it apart from monolayer graphene. In this study, we explore the synergistic effects of carbon vacancies, in conjunction with phosphorus dopants, across BLG, focusing on their impact on structural, magnetic, electrical, and hydrogen adsorption properties. Our findings reveal that the substitutional doping of a phosphorus atom into a single carbon vacancy in a graphene layer induces substantial structural distortion in BLG. In contrast, doping phosphorus into a double vacancy maintains the flat structure of graphene layers. These distinct layer structures affect the electron distribution and spin arrangement, leading to varied electronic configurations and intriguing magnetic behaviors. Furthermore, the presence of abundant unsaturated electrons around the vacancy promotes the capture and bonding of hydrogen atoms. Hydrogen adsorption on BLG results in substantial orbital hybridization, accompanied by significant charge transfer. The calculated Gibbs free energies for hydrogen adsorption on BLG range from -0.08 to 0.09 eV, indicating exceptional catalytic activity for the hydrogen evolution reaction. These findings carry implications for optimizing the properties of graphene layers, making them highly desirable for applications such as catalysis.

Editorial for the Special Issue: "Advanced Nanomaterials for Electrochemical Energy Conversion and Storage"

Developing efficient and low-cost energy conversion and storage devices and technologies is all-important issue in order to achieve a low-carbon society, whose performance essentially depends on the properties of materials [...].

Self-Templating Synthesis of N/P/Fe Co-Doped 3D Porous Carbon for Oxygen Reduction Reaction Electrocatalysts in Alkaline Media

The development of low-cost, highly active, and stable oxygen reduction reaction (ORR) catalysts is of great importance for practical applications in numerous energy conversion devices. Herein, iron/nitrogen/phosphorus co-doped carbon electrocatalysts (NPFe-C) with multistage porous structure were synthesized by the self-template method using melamine, phytic acid and ferric trichloride as precursors. In an alkaline system, the ORR half-wave potential is 0.867 V (vs. RHE), comparable to that of platinum-based catalysts. It is noteworthy that NPFe-C performs better than the commercial Pt/C catalyst in terms of power density and specific capacity. Its unique structure and the feature of heteroatom doping endow the catalyst with higher mass transfer ability and abundant available active sites, and the improved performance can be attributed to the following aspects: (1) Fe-, N-, and P triple doping created abundant active sites, contributing to the higher intrinsic activity of catalysts. (2) Phytic acid was crosslinked with melamine to form hydrogel, and its carbonized products have high specific surface area, which is beneficial for a large number of active sites to be exposed at the reaction interface. (3) The porous three-dimensional carbon network facilitates the transfer of reactants/intermediates/products and electric charge. Therefore, Fe/N/P Co-doped 3D porous carbon materials prepared by a facile and scalable pyrolysis route exhibit potential in the field of energy conversion/storage.