Surface area and pore size characteristics of nanoporous gold subjected to thermal, mechanical, or surface modification studied using gas adsorption isotherms, cyclic voltammetry, thermogravimetric analysis, and scanning electron microscopy.
Surface area and pore size characteristics of nanoporous gold subjected to thermal, mechanical, or surface modification studied using gas adsorption isotherms, cyclic voltammetry, thermogravimetric analysis, and scanning electron microscopy.
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DOI：
10.1039/c2jm16633j
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发表时间：
2012
影响因子：
--
通讯作者：
Stine KJ
中科院分区：
文献类型：
--
作者：
Tan YH;Davis JA;Fujikawa K;Ganesh NV;Demchenko AV;Stine KJ
氮气吸附/解吸等温线用于研究物理改性、热退火和十八硫醇官能化 np-Au 整体材料的 Brunauer、Emmett 和 Teller (BET) 表面积和 Barrett-Joyner-Halenda (BJH) 孔径分布。我们提出了 N2 气体在 np-Au 上的完全吸附-解吸等温线，并观察了 IV 型等温线和 H1 型磁滞回线。使用扫描电子显微镜（SEM）检查了纳米金在各种热退火处理下的演变。热退火 np-Au 的外部和内部图像表明，所有独立式 np-Au 结构的孔隙率随着热处理温度的升高而降低。发现用 C18-SH 的自组装单层 (SAM) 修饰 np-Au 表面（基于使用热重分析 (TGA) 分解 C18-SH 覆盖 2.94 × 1014 cm−2 分子），可以降低氮气与 np-Au 表面相互作用的强度，这通过 C18-SH 的“C”参数的降低反映出来。 BET 方程。通过循环伏安法研究，我们发现在高温下退火的 np-Au 整料的表面积遵循与 BET 表面积研究和 SEM 形貌表征中发现的退火温度相同的趋势。该研究强调了控制具有高表面积和明确的可调节孔隙形态的独立式纳米多孔金块的能力。
Nitrogen adsorption/desorption isotherms are used to investigate the Brunauer, Emmett, and Teller (BET) surface area and Barrett-Joyner-Halenda (BJH) pore size distribution of physically modified, thermally annealed, and octadecanethiol functionalized np-Au monoliths. We present the full adsorption-desorption isotherms for N2 gas on np-Au, and observe type IV isotherms and type H1 hysteresis loops. The evolution of the np-Au under various thermal annealing treatments was examined using scanning electron microscopy (SEM). The images of both the exterior and interior of the thermally annealed np-Au show that the porosity of all free standing np-Au structures decreases as the heat treatment temperature increases. The modification of the np-Au surface with a self-assembled monolayer (SAM) of C18-SH (coverage of 2.94 × 1014 molecules cm−2 based from the decomposition of the C18-SH using thermogravimetric analysis (TGA)), was found to reduce the strength of the interaction of nitrogen gas with the np-Au surface, as reflected by a decrease in the ‘C’ parameter of the BET equation. From cyclic voltammetry studies, we found that the surface area of the np-Au monoliths annealed at elevated temperatures followed the same trend with annealing temperature as found in the BET surface area study and SEM morphology characterization. The study highlights the ability to control free-standing nanoporous gold monoliths with high surface area, and well-defined, tunable pore morphology.