The development of robust, cost-effective remediation technologies of selenium uptake from ground and surface water is challenging and at the same time urgently needed. The present study provides a new, facile synthesis protocol for lepidocrocite (γ-FeOOH) nanoflakes and lepidocrocite decorated on multi-layered graphene (γ-FeOOH-MLG) and their possible application for Selenate [Se(VI)] ions removal from drinking water. The morphological and structural properties of γ-FeOOH were studied by using different techniques. There is a limited data on the adsorption of Se(VI) ions onto the 2D γ-FeOOH nanosheets. This work delineates adsorption mechanism and merits of incorporating graphene for enhancing adsorbent’s potential for selenium removal from contaminated water. The extraordinary electronic and textural properties of graphene sheets make it a physical support to stabilize γ-FeOOH nanoflakes, substantially improving adsorption capacities and kinetics besides strengthening particle stability. Maximum adsorption capacity of γ-FeOOH and γ-FeOOH-MLG samples estimated by Langmuir adsorption isotherms observed to be ∼40.09 and ∼83.44 mg/g, respectively. The adsorption mechanism of Se(VI) to the surfaces of adsorbents was found to be monolayer and of chemisorption in nature. The pH dependence experiments showed that γ-FeOOH exhibited maximum adsorption capacity at a pH close to the PZC 5.97 (±1), which are in suitable for real ground water conditions.

从地下水和地表水吸收硒的健壮，经济高效的修复技术的发展具有挑战性，同时迫切需要。本研究提供了一种新的，简便的合成方法，用于修饰多层石墨烯（γ-FeOOH-MLG）上的纤铁矿（γ-FeOOH）纳米片和纤铁矿及其在饮用水中去除硒酸[Se（VI）]离子的可能应用。用不同的方法研究了γ-FeOOH的形貌和结构特性。关于Se（VI）离子在2Dγ-FeOOH纳米片上的吸附数据有限。这项工作描述了吸附机理和掺入石墨烯的优点，以增强吸附剂从污染水中去除硒的潜力。石墨烯片材非凡的电子和质构特性使其成为稳定γ-FeOOH纳米片的物理载体，除了增强颗粒稳定性外，还大大提高了吸附能力和动力学。通过Langmuir吸附等温线估算的γ-FeOOH和γ-FeOOH-MLG样品的最大吸附容量分别为〜40.09和〜83.44 mg / g。发现Se（VI）对吸附剂表面的吸附机理是单层的，并且在自然界中是化学吸附的。pH依赖性实验表明，γ-FeOOH在接近PZC 5.97（±1）的pH值下表现出最大的吸附容量，适合实际地下水条件。通过Langmuir吸附等温线估算的γ-FeOOH和γ-FeOOH-MLG样品的最大吸附容量分别为〜40.09和〜83.44 mg / g。发现Se（VI）对吸附剂表面的吸附机理是单层的，并且在自然界中是化学吸附的。pH依赖性实验表明，在接近于PZC 5.97（±1）的pH值下，γ-FeOOH表现出最大的吸附容量，适用于真实的地下水条件。通过Langmuir吸附等温线估算的γ-FeOOH和γ-FeOOH-MLG样品的最大吸附容量分别为〜40.09和〜83.44 mg / g。发现Se（VI）对吸附剂表面的吸附机理是单层的，并且在自然界中是化学吸附的。pH依赖性实验表明，γ-FeOOH在接近PZC 5.97（±1）的pH值下表现出最大的吸附容量，适合实际地下水条件。