Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
Guangdong Provincial Key Laboratory of Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
Environ Pollut. 2021 Jan 1;268(Pt A):115786. doi: 10.1016/j.envpol.2020.115786. Epub 2020 Oct 11.
Water contamination caused by radionuclides is a major environmental issue. Uranium (U) belongs to the actinide group of elements. Hexavalent uranium (U(VI)) is radioactively and chemically harmful and highly mobile in the environment and wastewater stream. Therefore, developing highly efficient materials for minimizing the environmental impact of U(VI) is essential. To achieve this goal, we successfully synthesized a novel material, namely graphene oxide (GO)/hydroxyapatite (HAP), by directly assembling GO and HAP through a facile hydrothermal method, which exhibits effective U(VI) removal and immobilization. The GO/HAP composite has an outstanding sorption capacity for U(VI) (i.e., 373.00 mg/g) within 5 min at a pH of 3.0. The parameters from thermodynamic analysis indicated that the GO/HAP composite absorbed U(VI) through a process of spontaneous and exothermic adsorption. XPS, XRD, and FT-IR results revealed that the composite's phosphate group was mainly responsible for U(VI) retention and incorporation. The GO/HAP composite's enhanced U(VI) sorption capacity is most likely ascribed to the synergistic effect after functionalizing with nano HAP. The current findings may greatly facilitate the creation of rational design strategies to develop highly efficient materials that can treat radioactive wastewater.
水环境污染是一个主要的环境问题。铀（U）属于锕系元素。六价铀（U(VI)）具有放射性和化学危害性，在环境和废水中高度移动。因此，开发高效的材料来最大限度地减少 U(VI)的环境影响是至关重要的。为了实现这一目标，我们通过简便的水热法成功合成了一种新型材料，即氧化石墨烯（GO）/羟基磷灰石（HAP），它通过直接组装 GO 和 HAP 来实现，表现出有效去除和固定 U(VI)的能力。GO/HAP 复合材料在 pH 值为 3.0 时，在 5 分钟内对 U(VI)具有出色的吸附容量（即 373.00mg/g）。热力学分析的参数表明，GO/HAP 复合材料通过自发和放热吸附过程吸收 U(VI)。XPS、XRD 和 FT-IR 结果表明，复合材料的磷酸盐基团主要负责 U(VI)的保留和掺入。GO/HAP 复合材料增强的 U(VI)吸附能力很可能归因于纳米 HAP 功能化后的协同效应。这一发现可能极大地促进了合理设计策略的创造，以开发能够处理放射性废水的高效材料。
