ABSTRACT
Surface-enhanced Raman scattering (SERS) is an ultrasensitive analytical method which has been applied in many fields, and the reproducibility of the substrate is important for reliable SERS analysis. In present work, an innovative method inspired by the flower planting process is put forward to acquire gold nanoflower (AuNF) SERS substrate. Three steps (digging holes, sowing the gold nanoseeds and seeds grow into gold nanoflowers) are included in the substrate fabrication process, and the influence of preparing conditions (like reacting time and Na3Au(SO3)2 concentration) on the substrate morphology and SERS performance are investigated. The acquired AuNF substrate not only exhibits good SERS performance but also possesses excellent reproducibility while being used to detect the rhodamine 6G (R6G) molecular. The relative standard deviation (RSD) of Raman signals among substrates acquired in distinct batches (substrate-to-substrate) is as low as 6.67 %. Since the AuNF substrate is prepared by the wet chemistry route based on seed-mediated growth and there are no expensive reagents or complicated process used, the new process to obtain AuNF substrate is cost-effective and easy to scale up.
ABSTRACT
Lithium-ion batteries (LIBs) play a pivotal role as essential components in various applications, including mobile devices, energy storage power supplies, and electric vehicles. The widespread utilization of LIBs underscores their significance in the field of energy storage. High-performance LIBs should exhibit two key characteristics that have been persistently sought: high energy density and safety. The separator, a critical part of LIBs, is of paramount importance in ensuring battery safety, thus requiring its high thermal stability and uniform nanochannels. Here, the novel ion-track etched polyethylene terephthalate (ITE PET) separator is controllably fabricated with ion irradiation technology. Unlike conventional polypropylene (PP) separators, the ITE PET separator demonstrated vertically aligned nanochannels with uniform channel size and distribution. The remarkable characteristics of the ITE PET separator include not only high electrolyte wettability but also exceptional thermal stability, capable of withstanding temperatures as high as 180 °C. Furthermore, the ITE PET separator exhibits a higher lithium-ion transfer number (0.59), which is advantageous in enhancing battery performance. The structural and inherent advantages of ITE PET separators contribute to enhance the C-rate capacity, electrochemical, and long-term cycling (300 cycles) stability observed in the corresponding batteries. The newly developed method for fabricating ITE PET separators, which possess high thermal stability and a uniform channel structure, fulfills the demand for high-temperature-resistant separators without requiring any modification procedures. Moreover, this method can be easily scaled up using simple processes, making it a competitive strategy for producing thermotolerant separators.
ABSTRACT
Surface-enhanced Raman scattering (SERS), due to its high detecting sensitivity and rapid data acquisition ability, has been considered as a powerful technique for label-free ultrasensitive detection of chemical and biochemical analytes. As an important part, the uniform SERS substrate is the prerequisite for this technology being used in all the related areas. Therefore, seeking the fast, convenient and low-cost way to obtain the SERS substrate with high performance and reproducibility never stops in recent decades. In this work, the PC membrane with uniform nanopores obtained by ion irradiation and chemical etching (i.e., ion-track etched PC membrane) was first used to prepare the gold nanostar SERS substrate. The monolayer gold nanostars can be obtained through a one-step redox reaction on the surface of the PC membrane, which not only can act as the base of SERS substrate but also can work as the reaction adjuster. By optimizing the growth conditions, the SERS substrate with uniform monolayer gold nanostars can be fabricated without any complicated procedures and costly equipment fast (in 20 mins). Meanwhile, the prepared flexible gold nanostar SERS substrate exhibits excellent Raman performance, which can effectively detect the analyte R6G with the concentration as low as 1 × 10-10 M and the SERS enhancement factors can be around 3.70 × 105. The new facile SERS substrate preparation method is cost-effective, convenient, fast and easily scale up, which can satisfy the requests of the real applications in many fields.
