Emerging Roles of Surfactants in Engineering Two-Dimensional Nanomaterials for Advanced Applications

Two-dimensional (2D) nanomaterials offer promising properties for energy storage, drug delivery, and environmental remediation, but their performance can be limited by aggregation, restacking, and challenges in controlling morphology and surface properties. Surfactants provide versatile tools for addressing these limitations through surface adsorption, template-directed growth, exfoliation, and dispersion stabilization. This review critically examines how surfactant-assisted strategies influence the synthesis, morphology, interfacial properties, and stability of 2D nanomaterials and how these changes relate to application performance. Representative studies are considered across drug delivery, energy storage, and environmental remediation, with attention to reported outcomes such as pollutant adsorption, oil–water separation, electrical conductivity, and photocatalytic activity. Where available, quantitative results are compared across representative studies, highlighting reported performance improvements and the limitations of cross-study comparisons. The review also distinguishes the direct effects of surfactant–material interactions from performance changes associated with morphology, surface chemistry, defects, and interlayer structure. Practical surfactant selection requires balancing dispersion and structural control against potential active-site blockage, impaired charge or ion transport, purification demands, environmental concerns, and production costs. Residual surfactants, inconsistent processing, limited reproducibility, and scalability remain important challenges. By connecting processing mechanisms with application outcomes and practical limitations, this review identifies priorities for more systematic surfactant selection, improved process control, and environmentally responsible, reproducible production of 2D nanomaterials.