近年来，工业和核能的快速发展产生了大量重金属及放射性废水，一旦排入环境将严重威胁人体健康和环境安全。因此，开发新型复合材料以强化典型重金属离子及放射性核素（铬、铀和铕）的去除意义重大。新型二维纳米材料二硫化钼，由于其表面硫原子对多种重金属离子表现出高效结合能力和还原性能，且来源广泛、化学稳定性强、耐辐射等而受到广泛关注，然而仍存在对目标污染物选择性差、吸附容量低等不足。基于此，本研究开发二硫化钼基复合材料，提高水中铬（Cr(VI)）、铀（U(VI)）和铕（Eu(III)）的高效选择性去除，结合静态吸附实验和光谱分析等手段深入探究不同条件下复合材料的吸附性能及作用机理。具体工作和主要研究成果为：

（1）以传统水热法制备了聚乙烯吡咯烷酮（PVP）、聚丙烯酰胺（PAM）共改性二硫化钼复合材料（MoS₂/PVP/PAM），用于Cr(VI)的去除。通过SEM、TEM、XRD、FTIR和XPS等表征结果，明确了PVP和PAM对MoS₂层间距和分散性的调控作用。静态吸附实验表明，PVP和PAM中的吡咯氮和氨基可以协同强化MoS₂的Cr(VI)分离性能，在较宽的pH范围内，MoS₂/PVP/PAM对Cr(VI)均可实现优异的吸附性能，最大吸附容量达274.73 mg/g，遵循拟二级动力学模型和Langmuir吸附模型。即使在不同浓度腐殖酸（HA）及共存离子条件下，该复合材料仍具有良好的Cr(VI)去除能力，且多种竞争离子共存时具有高选择性，对Cr(VI)的分配系数高达1.69×10⁷ mL/g。分析认为，MoS₂/PVP/PAM对Cr(VI)的去除机理主要为静电作用、化学还原（Cr(VI)还原成Cr(III)）和表面螯合的协同作用。

（2）通过反相交联法制备了壳聚糖交联的二硫化钼（MoS₂/CS），同时引入磷酸基团，制备了对U(VI)和Eu(III)高亲和力的磷酸改性二硫化钼/壳聚糖复合材料（MoS₂/CS-P）。MoS₂/CS-P对U(VI)和Eu(III)表现出超快的吸附动力学（5 min），吸附容量分别达到972.79和302.04 mg/g。在自来水和天然地表水中对U(VI)和Eu(III)的去除率均在97%和95%以上，即使在天然海水中，对U(VI)和Eu(III)的去除率仍达到82.20%和87.68%。经过五次再生循环后，对U(VI)和Eu(III)的吸附容量仍保持在原来的92.15%和88.55%。FTIR和XPS分析表明，MoS₂/CS-P表面的C-O、P-O、P=O官能团和S原子均可作为活性位点吸附U(VI)和Eu(III)。

（3）考虑到MoS₂/CS-P复合材料对U(VI)优异的去除性能，以及粉末材料在水处理应用中回收困难的问题，进一步采用刮刀涂覆法和磷酸浸泡法制备了MS/CS/PVDF-P复合膜。通过调控MoS₂含量和磷酸浓度，优化复合膜吸附性能。研究发现，在酸性条件下仍具有良好的U(VI)去除效果，最大吸附容量达24.82 mg/g（1178.54 mg/g-活性层），吸附过程不受共存阴离子干扰。在天然地表水中，对U(VI)的去除率达到92.53%，经过五次循环后，对U(VI)的去除率为83.43%。可见，MS/CS/PVDF-P是一种性能优异、易于回收、具有良好耐腐蚀性的U(VI)吸附材料。

总之，本文成功制备了用于Cr(VI)吸附的MoS₂/PVP/PAM复合材料，用于高效富集U(VI)、Eu(III)的MoS₂/CS-P复合材料以及易于回收再生的MS/CS/PVDF-P复合膜，在实际水处理中表现出较高的应用潜力。本研究为重金属及核素废水处理提供了理论支持，也为高效复合材料的研发提供有效思路。

In recent years, the rapid development of industry and nuclear energy has generated a large number of heavy metals and radioactive wastewater. Once discharged into the environment, it will seriously threaten human health and environmental safety. Therefore, developing novel composites to enhance the removal of representative heavy metals and radionuclides (chromium, uranium, and europium) is of great significance. Molybdenum disulfide, a new two-dimensional nanomaterial, has attracted extensive attention due to the high binding capacity and reduction performance of sulfur atoms to a variety of heavy metal ions, and its wide source, strong chemical stability, and radiation resistance. However, there are still deficiencies such as poor selectivity to target pollutants and low adsorption capacity. Based on this, this study developed molybdenum disulfide matrix composites for efficient and selective adsorption of chromium (Cr(VI)), uranium (U(VI)), and europium (Eu(III)) in water. Static adsorption experiments and spectral analysis techniques were used to investigate the adsorption performance and mechanism of the composites under different conditions. The specific work and major research findings are as follows:

(1) Molybdenum disulfide composites (MoS₂/PVP/PAM) co-modified with polyvinylpyrrolidone (PVP) and polyacrylamide (PAM) were prepared using a conventional hydrothermal method, and used for the adsorption of Cr(VI). The effects of PVP and PAM on the interlayer spacing and dispersion of MoS₂ were clarified through SEM, TEM, XRD, FTIR, and XPS characterization. The results of adsorption experiments showed that the pyrrole nitrogen and amino in PVP and PAM could synergically enhance the capacity of MoS₂ to remove Cr(VI). Over a wide pH range, MoS₂/PVP/PAM had excellent removal performance on Cr(VI). The maximum adsorption capacity of Cr(VI) was 274.73 mg/g, which was consistent with the pseudo-second-order kinetics model and Langmuir adsorption model. Even under different concentrations of humic acid (HA) and coexisting ion conditions, the composites still had good adsorption performance for Cr(VI). When multiple competitive ions coexisted, the distribution coefficient for Cr(VI) reached 1.69×10⁷ mL/g, showing excellent selectivity. It is concluded that the removal mechanisms of Cr(VI) were mainly the synergistic effect of electrostatic action, chemical reduction (Cr(VI) to Cr(III)), and surface chelation.

(2) Chitosan crosslinked molybdenum disulfide (MoS₂/CS) was prepared by the reversed-phase crosslinking method, and phosphate groups were introduced to prepare phosphate-modified molybdenum disulfide/chitosan composites (MoS₂/CS-P) with a good affinity for U(VI) and Eu(III). MoS₂/CS-P exhibited ultrafast adsorption kinetics for U(VI) and Eu(III) (5 min), and the adsorption capacities reached 972.79 and 302.04 mg/g, respectively. The removal rates of U(VI) and Eu(III) in tap water and natural surface water were above 97% and 95%. Even in natural seawater, the removal rates of U(VI) and Eu(III) were 82.20% and 87.68%, respectively. After five regeneration cycles, the adsorption capacity of U(VI) and Eu(III) remained at 92.15% and 88.55% of the original values. The results of FTIR and XPS analysis showed that the C-O, P-O, P=O functional groups and S atoms on the MoS₂/CS-P surface could be used as active sites to adsorb U(VI) and Eu(III).

(3) Considering the excellent U(VI) removal performance of MoS₂/CS-P composites, and the difficulty of recovering powder materials in water treatment applications, MS/CS/PVDF-P composite membrane was further prepared using the scraper coating method and phosphoric acid immersion method. The adsorption performance of the composite membrane was optimized by changing the MoS₂ content and phosphoric acid concentration. It still had good U(VI) removal performance under acidic conditions, and the maximum adsorption capacity was 24.82 mg/g (1178.54 mg/g-active coating). Moreover, the adsorption process was not affected by coexisting anions. In natural surface water, the removal rate of U(VI) was 92.53%, and after five cycles, the removal rate of U(VI) was 83.43%. Therefore, MS/CS/PVDF-P was a U(VI) absorbent with excellent performance, easy recovery, and good corrosion resistance.

In summary, we successfully prepared MoS₂/PVP/PAM composites for Cr(VI) adsorption, MoS₂/CS-P composite materials for efficient enrichment of U(VI) and Eu(III), and MS/CS/PVDF-P composite membrane that was easy to recover and regenerate. The prepared materials showed high application potential in actual water treatment. This study provided theoretical support for the treatment of heavy metal and nuclide wastewater, and also provided effective ideas for the development of efficient composites.