reported as a new effi cient Fenton-like catalyst for yielding oxidative hydroxyl radicals (HO•) to degrade organic contaminants. [ 5 ] Other applications are rarely reported in the literature. In any case, it is commonly accepted that the performances are closely related with morphology, structure, specifi c area, and chemical stability of FeOCl nanomaterials, which strongly depends on the preparation strategies and experimental conditions. [ 6 ] For decades, however, almost all the reported FeOCl materials were obtained by one exclusive strategy, the chemical vapor transport (CVT), which utilizes FeCl 3 and Fe 2 O 3 mixed powders as precursor and requires a heating procedure at a temperature of 380 °C over days. [ 5,7 ] The CVT strategy is extremely time consuming and asobtained FeOCl materials possess single morphology of nanoplate with micrometer dimensions. Also, the fi nite experimental parameters make it diffi cult to effectively modulate the microstructure, morphology and composition, which limits its practical applications in fi elds of catalysis, energy storage, and conducting materials. Recently, we developed a new technique, laser ablation in liquid solution (LAL), to facilely synthesize the crystalline FeOCl nanosheets at ambient conditions. By laser ablating Au foil in surrounding FeCl 3 solutions for minutes, spherical Au nanoparticles (NPs) decorated FeOCl nanosheets could be synthesized in a one-pot procedure. Technical characterizations illustrate that the crystalline nanosheets possess (010) preferred orientations with microsized dimensions in the plane and tens of nanometers in thickness. The Au/FeOCl nanocomposites own good thermal stability and surface of which adsorbs abundant H 2 O molecularly and oxygen species chemically. The fabrication route is simple and much more effi cient compared to the traditional CVT method. Furthermore, the crystalline size and proportion of Au or FeOCl in the nanocomposites could be effectively modulated by simply changing FeCl 3 concentrations. We proposed that the localized liquid region, formed around the interface between LAL-induced plasma plume and surrounding liquid, provides the hydrolysis reaction platform for the formation of FeOCl nanosheets.

Practical application of surface-enhanced Raman spectroscopy (SERS) is greatly limited by the inaccurate quantitative analyses due to the measuring parameter’s fluctuations induced by different operators, different Raman spectrometers, and different test sites and moments, especially during the field tests. Herein, we develop a strategy of quantitative SERS for field detection via designing structurally homogeneous and ordered Ag-coated Si nanocone arrays. Such an array is fabricated as SERS chips by depositing Ag on the template etching-induced Si nanocone array. Taking 4-aminothiophenol as the typical analyte, the influences of fluctuations in measuring parameters (such as defocusing depth and laser powers) on Raman signals are systematically studied, which significantly change SERS measurements. It has been shown that the silicon underneath the Ag coating in the chip can respond to the measuring parameters’ fluctuations synchronously with and similar to the analyte adsorbed on the chip surface, and the normalization with Si Raman signals can well eliminate the big fluctuations (up to 1 or 2 orders of magnitude) in measurements, achieving highly reproducible measurements (mostly, <5% in signal fluctuations) and accurate quantitative SERS analyses. Finally, the simulated field tests demonstrate that the developed strategy enables quantitatively analyzing the highly scattered SERS measurements well with 1 order of magnitude in signal fluctuation, exhibiting good practicability. This study provides a new practical chip and reliable quantitative SERS for the field detection of real samples.