Construction of Thermally\nRobust SERS Nanostructure\nfor High-Temperature In Situ Analysis

High-temperature reactions serve as the basis of various\nmodern\nchemical industries. Surface-enhanced Raman spectroscopy (SERS) has\ndemonstrated significant advantages in operando characterization,\nparticularly in the trace analysis of surface species, which is pivotal\nfor functionality. However, its application in high-temperature processes\nhas revealed a notable decline in sensitivity, primarily attributed\nto the inadequate thermal stability of the SERS amplifier. The simultaneous\nachievement of high SERS activity, thermal robustness, and substrate\nadaptability in Raman signal amplifiers stands as a pressing necessity\nfor broadening the scope of SERS to high-temperature operando studies.\nThis study reports a hybrid nanostructure of Au-embedded core–shell\nnanospheres (Au-ECSNs), which not only achieve a SERS enhancement\nfactor higher than 10<sup>4</sup> but also exhibit thermal stability\nup to 600 °C, along with unrestricted substrate generality. Utilizing\nthree-dimensional finite-difference time-domain (3D-FDTD) simulation,\nthe optimal structural parameters of the Au-ECSNs are identified and\nexperimentally verified by Rhodamine 6G analysis, pyridine adsorption,\nand thermal robustness tests. Furthermore, the feasibility of Au-ECSNs\nfor high-temperature applications is demonstrated by the trace analysis\nof carbon species and dynamic monitoring of ceria nitrate decomposition\nunder operando conditions. This work presents a potential strategy\nfor in situ SERS analysis of high-temperature processes, particularly\nfocusing on trace detection of surface species or dynamic monitoring\nof phase transformations, which is of critical importance in surface\nchemistry, heterogeneous catalysis, and electrochemical energy advancements.