Single-Atom Rhodium on Defective g-C₃N₄: A Promising Bifunctional Oxygen Electrocatalyst

Abstract

It is highly desirable to design bifunctional electrocatalysts to realize highly efficient oxygen evolution/reduction reaction (OER/ORR). Herein, density functional theory (DFT) calculations were conducted to validate the feasibility of a single transition metal (TM) embedded in defective g-C 3 N 4 for bifunctional oxygen electrocatalysis. It was clarified that the TM atom supported on defective g-C 3 N 4 with N vacancy (TM/V N -CN) was stable and possible to be synthesized. Remarkably, Rh/V N -CN exhibited low overpotentials of 0.32 and 0.43 V for OER and ORR, respectively, and was considered as the promising bifunctional catalyst. The volcano plots and contour maps were established based on the scaling relation of adsorption energies of *OH, *O, and *OOH. The OER/ORR activity origin was revealed by descriptors of the d-band center and the number of d-orbital electrons multiplied electronegativity of TM. Furthermore, the machine learning (ML) algorithm was utilized to analyze the intrinsic correlation between catalytic activity and a series of structural and atomic features. Our combined DFT and ML work not only opts for the promising bifunctional oxygen electrocatalysts but also provides guidance for the design of single-atom catalysts and the discovery of more efficient catalysts.

Coordination environments tune the activity of oxygen catalysis on single atom catalysts: A computational study

“…where * stands for the active sites of the catalyst surface. To calculate the Gibbs reaction free energy change (ΔG) for each individual step, the experimental reaction energy of 2H 2 O → O 2 + 2H 2 (4.92 eV) is taken into consideration to calculate the free energy of O 2 gas [54,55]. Then according to Eqs.…”

A Feasible Strategy for Identifying Single‐Atom Catalysts Toward Electrochemical NO‐to‐NH3 Conversion

“…[ 16 ] 2D materials have been widely used for stabilizing the atomically dispersed metal atoms. [ 16a,17 ] Particularly, the C 2 N monolayer is a valid form of N‐doped graphene synthesized via a wet chemical reaction. [ 18 ] With the six sp 2 ‐hybridized nitrogen atoms at the hole edge, the natively uniform cavities of C 2 N provide advantageous coordinated sites for transition metals (TM).…”

g‐C3N4‐Based 2D/2D Composite Heterojunction Photocatalyst

“…Recent literatures report the application of machine learning in common photocatalysts such as TiO 2 , [158] ZnO [159] and g-C 3 N 4 . [160] The results from machine learning could guide the design and fabrication of g-C 3 N 4 -based 2D/2D heterojunction photocatalysts with better performance. The descriptor includes the work functions and band structures of the constituent photocatalysts, the binding energy and interfacial electron interaction of the composite, the energy variation of molecule adsorption and surface redox reaction.…”