球磨（BM）作为无溶剂技术已被广泛用于定制具有高孔隙率和良好分散性的生物炭基吸附剂，以增强其环境应用。在这项研究中,用BM法成功制备了球磨层状双氢氧化物（LDHs）生物炭复合材料（B-LDHs-BC），用于Cd（II）吸附，并研究了BM对LDHs-BC结构性能关系的影响。固态表征表明LDH被BM成功地剥离在B-LDHs-BC表面上，这通过LDH的扩大的基础间距和减小的微晶尺寸来鉴定。尽管B-LDHs-BC的BET表面积（226m2/g）略低于球磨BC，B-LDHs-BC具有较多的含O官能团和较高的吸附容量(119mg/g)。动力学实验表明,B-LDHs-BC对Cd(II)的去除是通过物理和化学两种吸附过程,液膜扩散是速率控制步骤。正BM效应主要诱导更丰富的酸性官能团和活性吸附位点，从而增强了B-LDHs-BC的Cd(II)性能。这项工作证明了一种简便的无溶剂生产剥离LDHs改性BC复合材料的方法，并很好地说明了BM效应，可以扩展其在环境中的实际应用。
Ball milling (BM) as a solvent-free technology has been widely used to tailor the biochar-based adsorbents with high porosity and well dispersion for enhancing their environmental applications. In this study, the ball-milled layered double hydroxides (LDHs) biochar composite (B-LDHs-BC) was successfully fabricated with BM method for Cd(II) adsorption and the BM effects on the LDHs-BC structure-performance relationships were investigated. The solid-state characterization demonstrated the LDHs were successfully exfoliated by BM on the B-LDHs-BC surface which was identified by the enlarged basal spacing and reduced crystallite size of the LDHs. Although the BET surface area of B-LDHs-BC (226 m2/g) was slightly lower than the ball-milled BC, the B-LDHs-BC had more O-containing functional groups and higher adsorption capacity (119 mg/g). The kinetics experiments indicated that the Cd(II) removal by B-LDHs-BC was through both the physical and chemical adsorption processes, and the liquid membrane diffusion was the rate-controlling step. The positive BM effects mainly induced more abundant acidic functional groups and active adsorption sites, and thus enhanced Cd(II) performance of B-LDHs-BC. This work demonstrated a facile solvent-free method for production of the exfoliated LDHs modified BC composite, and also well illustrated the BM effects which can extend their practical use in environment.
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