载铜氮化碳纳米片对单质汞的吸附脱除特性

用简易热剥离法合成了氮化碳纳米片（CNNS），再通过等体积浸渍法将铜负载于CNNS表面合成了载铜CNNS吸附剂，用于低温下吸附脱除气态单质汞（Hg⁰）.利用氮气吸附-脱附、X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线光电子能谱（XPS）等手段对吸附剂进行表征.结果表明：CNNS对Hg⁰具有良好的吸附性能，吸附温度为120℃时，脱汞效率约为54.2%；载铜修饰可极大提高CNNS的脱汞活性，脱汞效率在40~240℃温度范围内均大于82.3%，这归因于铜与氮化碳间的紧密接触.煅烧温度对载铜CNNS的脱汞活性影响较大，最佳煅烧温度为200℃.通过载铜修饰可有效活化CNNS，提高其对Hg⁰的氧化能力，这可能归因于铜离子与氮化碳之间的莫特-肖特基电子转移效应.SO₂和水蒸气对载铜CNNS的脱汞性能有抑制作用.

Adsorption removal of elemental mercury on Cu-loaded carbon nitride nanosheet

Carbon nitride nanosheet (CNNS) was synthesized via a facile thermal exfoliation approach and employed for adsorption removal of gaseous elemental mercury (Hg⁰) at low temperature. The sorbents were characterized by nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) techniques. The results showed that CNNS performed well toward Hg⁰ adsorption with a removal efficiency around 54.2% at 120℃. The Hg⁰ removal efficiency of CNNS could be greatly enhanced by Cu-modification to more than 82.3% at the temperature range of 40 to 240℃ due to the intimate contact of copper and carbon nitride. Calcination temperature had a big influence on Hg⁰ capture ability of Cu-modified CNNS. The optimal annealing temperature was 200℃. CNNS could be efficiently activated by Cu-modification and its Hg⁰ oxidation ability was enhanced, probably attributed to the Mott-Schottky electron transfer effect between Cu ions and carbon nitrides. SO₂ and H₂O can inhibit Cu-modified CNNS's Hg⁰ removal performance.