Catalysts, Journal Year: 2025, Volume and Issue: 15(4), P. 311 - 311
Published: March 25, 2025
Na−O2 batteries are plagued by high cathodic oxygen reduction (ORR)/oxygen evolution (OER) overpotentials during discharging/charging. Herein, we constructed six carbide/nitride MXenes (M2XO2, M = Ti, Zr, and Hf, X C, N) investigated their performance as cathodes for first-principles calculations. M2CO2 have a pseudogap, showing semiconducting properties, while M2NO2 conductive. The nucleophilic O on the M2XO2 surfaces prefers to bind with Na atoms of NaxO2 intermediates activate Na−O bonds, improving sodium deintercalation. For all MXenes, OER overpotential is higher than ORR overpotential, forming bottleneck batteries. originate from too-strong adsorption MXenes. Lowering p-band center can weaken adsorption, thereby reducing overpotential. Consequently, carbides lower those nitrides further decrease decreasing atomic number. Ti2CO2 MXene shows extremely low ORR, OER, total (0.23, 0.32, 0.55 V), suggesting huge potential in
Language: Английский