Nanostructures for In Situ SERS Analysis of High-Temperature Processes

Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive analytical technique based on Raman scatter and utilizes the nanostructures of active metals, such as gold and silver, with roughened surfaces as a signal amplifier. With its enhancement effect and “fingerprint” ability, in situ SERS is able to capture the dynamics of microstructure evolution and trace surface species in real time, which provides direct information for the analysis of a reaction mechanism in various surface processes, including heterogeneous catalysis, electrochemical reactions, etc. To date, SERS has been widely used in operando analysis of surface processes under ordinary temperatures. For application in high-temperature processes, the harsh environment puts forward additional requirements in addition to high sensitivity for the SERS nanostructures, especially concerning thermal stability, chemical inertness, and surface universality. Therefore, it is necessary to develop specialized SERS nanostructures for in situ analysis of high-temperature processes. This paper reviews the research progress of the design and application of nanostructures for in situ SERS analysis of high-temperature processes, with special focus on how to solve the stability and sensitivity contradiction of the SERS nanostructures in the high-temperature complex environment through the design and regulation of the nanostructures. For the structure design, the strategies, preparation, and performance of the reported nanoarchitectures are compared. For the high-temperature application, the utilization of SERS nanostructures in in situ studies are summarized, including thermal crystallization, lattice dynamics, heterogeneous catalysis, and high-temperature electrode reactions.