Edge-Site Engineering of MoS ₂ Nanosheets via Controlled H ₂ O ₂ Etching for High-Performance in Li−CO ₂ Batteries

Lithium−carbon dioxide (Li−CO 2 ) batteries are promising energy storage systems due to their high theoretical energy density and capability for CO 2 utilization, yet their practical performance is limited by sluggish reaction kinetics. Here, we report an effective edge-site engineering strategy to enhance the catalytic activity of MoS 2 nanosheets via controlled H 2 O 2 etching. Density functional theory (DFT) calculations reveal that edge sites exhibit significantly stronger adsorption toward key intermediates (Li, CO 2, and Li 2 CO 3 ) than the basal plane, identifying them as dominant active centers. Guided by this insight, a series of MoS 2 nanosheets with tunable edge-site densities were synthesized on carbon paper. Structural characterizations confirm that moderate etching effectively increases edge-site exposure while preserving structural integrity. Electrochemical measurements demonstrate that the optimized MoS 2 -45 s electrode delivers a low overpotential of 0.77 V, excellent rate capability, and stable cycling over 700 h with an energy efficiency exceeding 75%. In short, our work highlights the critical role of edge-site regulation in improving catalytic performance and provides a rational strategy for designing advanced cathode materials for Li−CO 2 batteries.