标题： SERS拉曼检测CO$_2$湿度循环 显示英文标题

标题： SERS Raman detection of the CO$_2$ Moisture Swing

摘要： 可扩展、节能的二氧化碳捕获技术的发展对于实现净零排放至关重要。 湿度循环吸附剂通过湿度驱动的离子水解实现可逆的CO$_2$结合，为传统热再生方法提供了一种有前景的替代方案。 在本研究中，我们利用吸附测量和原位表面增强拉曼光谱，研究了两类MS材料中的阴离子种类动态变化，一种是含有碳酸氢根阴离子的阴离子交换树脂，另一种是浸渍有碳酸氢钾盐的活性炭。 采用镀镍银纳米线作为SERS基底，以增强信号强度，并在空气和氮气气氛下，在受控湿度条件下实现实时检测碳酸盐、碳酸氢盐和氢氧根物种。 结果揭示了阴离子种类的湿度依赖性相互转化，显著的光谱位移证实了驱动MS机制的可逆水解反应。 在潮湿条件下，我们观察到碳酸氢盐信号的耗尽和碳酸盐物种的同时增加，这与湿度诱导的CO$_2$脱附一致。 这些发现不仅验证了湿度驱动的湿度循环吸附剂中阴离子交换的机理模型，还展示了SERS作为操作诊断工具在监测CO$_2$捕获介质方面的实际潜力。 在真实环境条件下解析和量化碳酸盐、碳酸氢盐和氢氧根离子的可逆转化能力，为下一代直接空气捕集应用吸附剂材料的合理设计、性能优化和质量控制提供了有价值的见解。 显示英文摘要

摘要： The development of scalable, energy-efficient carbon dioxide capture technologies is critical for achieving net-zero emissions. Moisture swing sorbents offer a promising alternative to traditional thermal regeneration methods by enabling reversible CO$_2$ binding through humidity-driven ion hydrolysis. In this study, we investigate the anion speciation dynamics in two classes of MS materials, an anion-exchange resin with bicarbonate anion and activated carbon impregnated with potassium bicarbonate salt using both sorption measurements and in situ surface-enhanced Raman spectroscopy. Ni coated Ag nanowires were employed as SERS substrates to enhance signal intensity and enable the real-time detection of carbonate , bicarbonate , and hydroxide species under controlled humidity conditions in both air and nitrogen atmospheres. The results reveal humidity-dependent interconversion between anionic species, with significant spectral shifts confirming the reversible hydrolysis reactions that drive the MS mechanism. Under humid conditions, we observed the depletion of bicarbonate signals and a concurrent increase in carbonate species, consistent with moisture-induced desorption of CO$_2$. These findings not only validate the mechanistic models of humidity-driven anion exchange in moisture swing sorbents but also demonstrate the practical potential of SERS as an operando diagnostic tool for monitoring CO$_2$ capture media. The ability to resolve and quantify the reversible transformation of carbonate, bicarbonate, and hydroxide ions under realistic environmental conditions provides valuable insight for the rational design, performance optimization, and quality control of next-generation sorbent materials for direct air capture applications.