Single transition metal-decorated C4N/MoS2 heterostructure for boosting oxygen reduction, oxygen evolution, and hydrogen evolution

Multifunctional electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution (HER) are required preconditions for the development of a highly promising new green energy conversion and storage technology. Herein, a comprehensive computation of the ORR, OER and HER catalytic performance for the pristine and metal-decorated C4N/MoS2 (TM-C4N/MoS2) is researched using density functional theory. Remarkably, Pd-C4N/MoS2 exhibits distinguished bifunctional catalytic performance with lower ORR/OER overpotentials of 0.34/0.40 V. Rh-C4N/MoS2 is the prospective trifunctional catalyst with the low ORR/OER/HER overpotentials of 0.48/0.55/-0.16 V, but its electrochemical stability needs to be further improved. Furthermore, the strong correlation between intrinsic descriptor (φ) and adsorption free energy of *OH verifies that the catalytic activity of TM-C4N/MoS2 is affected by active metal and surrounding coordination environment. The heap map has summarized the correlations of d-band center, adsorption free energy of reaction species, and φ as the vital parameter for ORR/OER overpotentials of designing catalysts. The electronic structure analysis uncovers the activity enhancement is due to the adjustable adsorption behavior of reaction intermediates on TM-C4N/MoS2. This finding paves the way to develop high-activity and multifunctional catalysts, making them suitable for multifunctional applications in the forthcoming critically needed green energy conversion and storage technologies.