Molybdenum disulfide (MoS₂) poses great potential in water treatment as a popular transition metal dichalcogenide, arousing considerable concern regarding its fates and risk in aquatic environments. This study revealed that the interplay with extracellular polymeric substances (EPS) of freshwater algae significantly changed the properties and toxicity of MoS₂ to aquatic fish. The predominant binding of aromatic compounds, polysaccharides, and carboxyl-rich proteins in EPS on the 1T polymorph of MoS₂ via hydrophilic effects and the preferential adsorption of carboxylic groups contributed to morphological alterations, structural disorders (band gap and phase alterations), and the attenuated aggregation of MoS₂ in aqueous solutions. Electron charge transfer and n-π* interactions with EPS decreased the catalytic activity of MoS₂ by inhibiting its capability of generating reactive intermediates. The dissolution of MoS₂ slowed down after interacting with EPS (from 0.089 to 0.045 mg/L per day) owing to rapid initial oxidation (i.e., forming Mo-O bond) and carbon grafting. Notably, the morphological and structural alterations after EPS binding alleviated the toxicity (e.g., malformation and oxidative stress) of MoS₂ to infantile zebrafish. Our findings provide insights into the environmental fate and risk of MoS₂ by ubiquitous EPS in natural waters, serving as valuable information while developing water treatment processes accordingly.

二硫化钼 (MoS ₂ ) 作为一种流行的过渡金属二硫属化物，在水处理中具有巨大的潜力，引起人们对其在水生环境中的命运和风险的相当关注。该研究表明，淡水藻类细胞外聚合物（EPS）的相互作用显着改变了 MoS ₂对水生鱼类的性质和毒性。EPS 中的芳香族化合物、多糖和富含羧基的蛋白质通过亲水作用与MoS ₂的 1T 多晶型物的主要结合和羧基的优先吸附导致形态改变、结构紊乱（带隙和相改变），以及MoS _{2 的}衰减聚集在水溶液中。电子电荷转移和与 EPS 的n -π* 相互作用通过抑制其生成反应中间体的能力降低了 MoS ₂的催化活性。由于快速的初始氧化（即形成 Mo-O 键）和碳接枝，MoS ₂的溶解在与 EPS 相互作用后减慢（从每天 0.089 到 0.045 mg/L）。值得注意的是，EPS 结合后的形态和结构改变减轻了 MoS ₂对幼年斑马鱼的毒性（例如，畸形和氧化应激）。我们的研究结果提供了对 MoS ₂的环境归宿和风险的见解 通过在天然水中无处不在的 EPS，在相应地开发水处理工艺时作为有价值的信息。