Abstract Carbon surfaces incorporating densely packed spikes with nanometer sharpness have shown exceptional electrocatalytic properties attributed to the enhanced electric field from the topography of the spikes. In this article, the composition of nanospike surfaces is identified by x-ray photoelectron spectroscopy (XPS) and their absolute work function determined using ultraviolet photoemission spectroscopy (UPS). Low temperature annealing of as-grown samples above 275 °C is required to produce a clean surface which has a 4.13 eV work function, a half volt lower than that of flat graphite. Treatments that contaminate the spiked surface, including exposure to air, oxidation at elevated temperature, or immersion in water or hydrocarbons, all increase the work function. Processing that blunts the spikes, including exposure to an oxygen plasma, argon sputtering, or high temperature annealing (800 °C) result in a work function close to that of flat graphite. An unusual double onset in the UPS secondary electron intensity is observed on as-grown nanospike samples and is reproduced by absorbing hydrocarbons on the surface. This double onset appears to be unique to carbon substrates and may originate in inelastic scattering of photoelectrons.

中文翻译：

---

清洁和改性碳纳米钉的功函数测量

摘要 碳表面包含具有纳米锐度的密集堆积的尖峰，由于尖峰形貌增强的电场，显示出卓越的电催化性能。在本文中，纳米尖峰表面的组成通过 X 射线光电子能谱 (XPS) 确定，并使用紫外光电子能谱 (UPS) 确定其绝对功函数。需要在 275 °C 以上对生长样品进行低温退火，以产生具有 4.13 eV 功函数的清洁表面，比扁平石墨低半伏。污染尖刺表面的处理，包括暴露在空气中、高温氧化或浸入水或碳氢化合物中，都会增加功函数。钝化尖峰的处理，包括暴露于氧等离子体，氩气溅射或高温退火 (800 °C) 导致功函数接近扁平石墨的功函数。在生长的纳米尖峰样品上观察到 UPS 二次电子强度的不寻常的双重起始，并通过在表面吸收碳氢化合物而重现。这种双重起始似乎是碳基材所独有的，可能源于光电子的非弹性散射。