The narrow interlayer spacing and terminal sulfur (S) inertness of the two-dimensional material MoS2 severely restrict ion diffusion and separation in capacitive deionization (CDI). Herein, we propose a mild surfactant-assisted ultrasonic exfoliation strategy to construct defect(S)-rich 1 T-MoS2(D-MoS2) nanosheets with simultaneously expanded interlayer spacing, avoiding high-temperature treatment and ion intercalation typically required by conventional methods. This strategy leverages the excellent amphiphilicity of F68 and the surface energy matching between F68 and 1 T-MoS2 to enhance exfoliation efficiency. When combined with ultrasonic treatment, it produces a loosely packed and porous nanosheet structure compared to flower-like MoS2 (F-MoS2), accompanied by an increased concentration of S vacancies. As a result, the specific surface area (SSA) increases from 3.28 m2·g−1 to 16.94 m2·g−1 (5.16-fold), the interlayer spacing expands from 9.79 to 10.12 Å, and the S vacancy concentration rises from 11.79 % to 14.87 %. The expanded interlayer spacing facilitates the rapid (de)intercalation of Zn2+, while the increased S vacancies provide more favorable active sites. Benefiting from these synergistic advantages, D-MoS2 exhibits excellent CDI performance. The salt adsorption capacity (SAC) of D-MoS2 for Zn2+ reaches 143.84 mg·g−1 at 1.2 V, representing one of the highest SAC reported for CDI electrodes to date. Density functional theory (DFT) calculations reveal that this synergistic engineering strategy reduces the Zn2+ diffusion energy barrier from 0.68 eV to 0.44 eV, which mechanistically accounts for the significantly enhanced Zn2+ diffusion and separation efficiency in CDI. This work pioneers a novel and mild strategy for interlayer and S defect modulation in MoS2, providing a versatile framework for advancing next-generation ion separation technologies via CDI.