Silicon and Phosphorus Co-doped Bipyridine-Linked Covalent Triazine Framework as a Promising Metal-Free Catalyst for Hydrogen Evolution Reaction: A Theoretical Investigation

Abstract

Electrocatalytic water spliting is the most attractive route for hydrogen production, but the development of nonprecious, stable, and high-performance catalysts for hydrogen evolution reaction (HER) to replace the scarce platinum group metal-based electrocatalysts is still a challenging task for the scientific community. In this work, within the framework of density functional theory computations, we have predicted that a silicon and phosphorus co-doped bipyridine-linked covalent triazine framework, followed by substitution of bipyridine hydrogens at the P-site with fluorine atoms, may be a potential catalyst for HER. Our predicted model system (SiPF-Bpy-CTF) exhibits a very low band gap (7 meV), which may exhibit facile charge transfer kinetics during HER. Using the Gibbs free energy for the adsorption of atomic hydrogen ( ) as the key descriptor, we have found that our proposed model system (SiPF-Bpy-CTF) exhibits superior HER catalytic activity, with its being close to the ideal value (0 eV).

Molybdenum Atom-Mediated Salphen-Based Covalent Organic Framework as a Promising Electrocatalyst for the Nitrogen Reduction Reaction: A First-Principles Study

“…COFs are a class of crystalline porous organic polymers with fascinating features of being structurally predesignable, functionally manageable, and synthetically controllable. , Recent years have witnessed a boom in COF chemistry in the field of electrocatalysts for various important reactions. − COFs as electrocatalysts provide certain advantages over other materials due to the following reasons: (i) COFs possess high surface area and the active catalytic sites are well exposed so that the substrates can easily access the sites. (ii) The porous nature of COFs helps in fast diffusion of reactants/products, thereby accelerating the reaction rate.…”

Dual-Silicon-Doped Graphitic Carbon Nitride Sheet: An Efficient Metal-Free Electrocatalyst for Urea Synthesis

“…The computational hydrogen electrode model, proposed by Nørskov et al is used to account for the Gibbs free energy change (Δ G ) for each elementary step as following where Δ E = electronic energy difference of product and reactant for each elementary step, ΔZPE = zero point energy difference, and Δ S = difference in entropy, where entropy values of the free gas molecules are adopted from the standard NIST database. Δ G U = + eU , where e = number of electrons involved and U = applied electrode bias, and Δ G field = rectification of free energy arising out of the formation of electrochemical double layer around the cathode, neglected here following the previous studies. ,− Δ G pH = K B T × ln 10 × pH = 0.059 × pH; throughout the entire study, it is assumed that all the reactions are performed in acidic media. Hence, pH = 0 is considered throughout this entire study because the potential limiting step and overpotential of the reaction (η = U equilibrium – U onset ) are independent of the pH value.…”

Graphitic Carbon Nitride Sheet Supported Single-Atom Metal-Free Photocatalyst for Oxygen Reduction Reaction: A First-Principles Analysis

“…However, the use of Si is not explored in depth in photocatalytic reactions. In a very recent study, it is proposed that a bipyridine linked covalent triazine framework codoped by Si and P can act as an efficient metal-free catalyst for the hydrogen evolution reaction . Very recently, Tang et al and Chowdhury et al .…”