Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, PR China.
J Colloid Interface Sci. 2012 Nov 15;386(1):277-84. doi: 10.1016/j.jcis.2012.07.034. Epub 2012 Jul 23.
We report the synthesis of barium phosphate (BP) nano-flake and its adsorption behavior to methyl blue (MB) in aqueous solution. The as-obtained BP nano-flake revealed pure rhombohedral crystal structure. The adsorption capacity of MB onto BP reached 1500 mg g(-1). The adsorption equilibrium results fitted well with the Freundlich isotherm model. The adsorption process took less than 30 min to reach equilibrium. The adsorption kinetics was elucidated by the pseudo-second-order kinetic equation. It followed 2-stage and 3-stage intra-particle diffusion models for the low and high concentration of dye solutions, respectively. The adsorption of MB using the BP nano-flake was highly selective, compared with the adsorption of other dyes. The interactions between MB and BP were mainly the ionic interaction and hydrogen bonds, which were confirmed by the X-ray photoelectron spectroscopic results and the density functional theory calculations. The BP nano-flake revealed less than 5% decrease in adsorption amount when it was recycled and reused five times. The present work shows that the BP nano-flake is promising for practical applications in MB removal from aqueous solutions.
我们报告了磷酸钡 (BP) 纳米薄片的合成及其在水溶液中对亚甲基蓝 (MB) 的吸附行为。所得到的 BP 纳米薄片呈现出纯的菱面体晶体结构。BP 对 MB 的吸附容量达到 1500 mg g(-1)。吸附平衡结果很好地符合 Freundlich 等温吸附模型。吸附过程在不到 30 分钟内达到平衡。吸附动力学可以用拟二级动力学方程来解释。对于低浓度和高浓度的染料溶液，吸附过程分别遵循 2 阶段和 3 阶段的内扩散模型。与其他染料相比，BP 纳米薄片对 MB 的吸附具有高度选择性。X 射线光电子能谱和密度泛函理论计算结果表明，MB 和 BP 之间的相互作用主要是离子相互作用和氢键。BP 纳米薄片在回收和重复使用五次后，其吸附量的下降小于 5%。本工作表明，BP 纳米薄片有望在实际应用中用于从水溶液中去除 MB。
