Abstract：
Graphene-based material is widely used to remove arsenic from water due to its layered structure with high surface area. Here, we have successfully synthesized Fe-La bimetallic modified graphite sheet materials to more efficiently remove As(III) from aqueous solution. The results showed that Fe-La-graphite sheets (FL-graphite sheets) have a larger specific surface area (194.28 m2·g-1) than graphite sheets (2.80 m2·g-1). The adsorption capacity of FL-graphite sheets for As(III) was 51.69 mg·g-1, which was higher than that of graphite sheets (21.91 mg·g-1), La-graphite sheets (26.06 mg·g-1), and Fe-graphite sheets (40.26 mg·g-1). The FL-graphite sheets conformed to the Freundlich and Dubinin-Radushkevich isotherm, and the maximum adsorption capacity was 53.62 mg·g-1. The removal process obeys intra-particle diffusion and pore diffusion for As(III). The results of batch adsorption experiments and characterization analyses demonstrated that oxidation, ligand exchange, and inner sphere complexation mechanisms involved in the adsorption of FL-graphite sheets to As(III) in comparison with graphite sheets. In addition, electrostatic attraction mechanism was found vital in the adsorption. Ecotoxicity assessment revealed that FL-graphite sheets have little influence on rice germination and growth, but reduced the toxicity of As(III) to rice. Therefore, the FL-graphite sheets have good practical application value in purifying As(III) polluted water with litter ecotoxicity.
摘要：
基于石墨烯的材料由于其具有高表面积的层状结构而被广泛用于从水中去除砷。这里,我们已经成功地合成了Fe-La双金属改性石墨片材料，以更有效地从水溶液中去除As（III）。结果表明，Fe-La-石墨片（FL-石墨片）比石墨片（2.80m2·g-1）具有更大的比表面积（194.28m2·g-1）。FL-石墨片对As(III)的吸附容量为51.69mg·g-1，高于石墨片(21.91mg·g-1)，La-石墨片(26.06mg·g-1),和Fe-石墨片（40.26mg·g-1）。FL石墨片符合Freundlich和Dubinin-Radushkevich等温线，最大吸附量为53.62mg·g-1。去除过程服从As（III）的颗粒内扩散和孔隙扩散。批量吸附实验和表征分析的结果表明,配体交换，与石墨片相比，FL-石墨片吸附到As（III）中所涉及的内球络合机制。此外,静电吸引机制在吸附中至关重要。生态毒性评估表明，FL-石墨片对水稻发芽和生长影响很小，但降低了As(III)对水稻的毒性。因此,FL-石墨片在净化具有生态毒性的As（III）污染水中具有良好的实际应用价值。
