The surface functionality of amorphous carbons is difficult to directly measure because of a lack of crystallinity and overwhelming signals derived from the bulk material. Biochar, a form of amorphous carbon containing considerable oxygen surface functionality, was probed using metal ions and X-ray photoelectron spectroscopy to simultaneously measure the presence and proximity of functional groups and determine the preferred binding modes of a variety of metal ions. These binding motifs were correlated to the efficiency of metal adsorption as determined using the Langmuir isotherm and stability with respect to leaching. Three binding motifs were apparent: physisorption (Cd²⁺, Mn²⁺, and Zn²⁺), chelation (Cu²⁺, Ni²⁺, and Zn²⁺), and hydrolysis/precipitation (Cu²⁺, Ni²⁺, and Pb²⁺).

中文翻译：

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使用束缚金属离子的X射线光电子能谱探测无定形碳的表面功能

无定形碳的表面官能度由于缺乏结晶性和从块状材料中获得的压倒性信号而难以直接测量。使用金属离子和X射线光电子能谱探测了生物炭（一种含有大量氧表面功能的无定形碳形式），以同时测量官能团的存在和邻近程度，并确定各种金属离子的优选结合方式。这些结合基序与使用Langmuir等温线确定的金属吸附效率和相对于浸出的稳定性相关。三种结合基序是显而易见的：物理吸附（Cd 2 ⁺，Mn ²⁺和Zn ²⁺），螯合（Cu 2 ⁺，Ni ²⁺，Zn ²⁺，和水解/沉淀（Cu 2 ⁺，Ni ²⁺和Pb ²⁺）。