Interfacial orbital asymmetry enables redox reactions at the MXene-water interface

Most synthetic reactions occur in homogeneous phases, where the electron orbitals of reactants are embedded in uniform chemical environments and experience symmetric electronic regulation. In contrast, heterogeneous interfaces (e.g., liquid/solid, gas/solid, or gas/liquid) impose intrinsic asymmetry on orbital distributions, giving rise to locally non-uniform electronic states that endow interfacial atoms with unique reactivity. Despite this potential, orbital-level asymmetry has rarely been deliberately exploited for chemical synthesis, particularly under environmentally benign conditions. Herein, we report a surface asymmetric orbital-driven redox reaction, exemplified by the transformation of benzeneseleninic acid (PhSeO₂H) into diphenyl diselenide (PhSe-SePh) at the Ti₃C₂T_x MXene-water interface. In this reaction, the hydrophobic Ti₃C₂T_x surface preferentially enriches PhSeO₂H and establishes strong interfacial coupling with surface Ti atoms. The resulting asymmetric orbital polarization at the solid-liquid interface induces localized electron enrichment on the Ti₃C₂T_x surface, thereby facilitating interfacial redox interactions with PhSeO₂H. Remarkably, the interfacial reaction proceeds efficiently in aqueous solution at room temperature, affording a high yield (95%) and enabling spontaneous phase separation of the product, which simplifies downstream purification. This work introduces a nano-enabled and mechanistically distinct redox pathway, highlighting the potential of asymmetric orbital-driven interfacial reactions for green synthetic chemistry.