Regulating intermediates adsorption/desorption behavior in multilayered 2D MoS2-(Ni, Fe)Sx/rGO heterostructure via built-in electric field-driven electron transfer for water splitting and zinc-air battery

Abstract

Deliberate construction of 2D/2D heterostructure with interfacial built-in electric field (BIEF) is a reliable strategy to address sluggish reaction kinetics through electronic structure optimization and reaction microenvironment modulation. Herein, a novel multilayered MoS₂-(Ni, Fe)S_x/rGO hierarchical hybrid was synthesized via interfacial BIEF and dimensional engineering, featuring metallic-phase MoS₂ (1T-MoS₂) nanosheets and (Ni, Fe)S_x nanoflakes vertically anchored on rGO. This 2D/2D heterostructure allows large interface contact area via interfacial S-bridge spatial confinement, which provides abundant transport pathways for BIEF-derived large electron transfer from (Ni, Fe)S_x to 1T-MoS₂, thus favoring rapid reaction kinetics. Benefiting from the strong interfacial electron coupling and synergistic co-catalytic effects, the as-obtained MoS₂-(Ni, Fe)S_x/rGO displays extraordinary multifunctional catalytic activity, as confirmed in extremely low overpotentials at 10 mA cm⁻² for HER (38 mV) and OER (213 mV), along with a positive half-wave potential for ORR (0.82 V), thus delivering excellent efficiency and stability in water splitting and zinc-air batteries. Combining theoretical calculations and the in-situ characterizations, the reconfiguration of electronic structure and appropriate d-band center, driven by asymmetrical charge distributions arising from the interface-induced BIEF, endows key intermediates with balanced adsorption/desorption capability, thereby enhancing intrinsic catalytic activity and reducing reaction energy barriers.