Electrode

Organic chemistry

Electrocatalyst

Rhodium

Atom (system on chip)

Oxygen evolution

Density functional theory

Catalysis

Electronegativity

Computational chemistry

Physical chemistry

Embedded system

Chemistry

Computer science

Bifunctional

Electrochemistry

Oxygen

ACS Sustainable Chemistry & Engineering

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-C3N4 for bifunctional oxygen electrocatalysis. It was clarified that the TM atom supported on defective g-C3N4 with N vacancy (TM/VN-CN) was stable and possible to be synthesized. Remarkably, Rh/VN-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.

Single-Atom Rhodium on Defective g-C<sub>3</sub>N<sub>4</sub>: A Promising Bifunctional Oxygen Electrocatalyst

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

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