Invia reflex system

The chemical composition was determined using EDS (Oxford Instruments X-Max detector integrated with Zeiss' Ultra scanning electron microscope). The metal content was determined at 10 or more randomly selected areas on each sample and the average was taken as the intercalant concentration.
XRD measurements were performed using Bruker D8 Discover diffractometer with Cu Kα radiation (λ=1.5406 Å). Before each measurement, samples were roughly ground and mixed with paraffin oil, and then sealed in an airtight XRD sample holder (Bruker, A100B36/B37) inside the glovebox. XRD spectra were obtained at room temperature in the 2θ range of 5–75° with a step of 0.03° and a dwell time of 0.5 s per step.
Raman spectroscopy was performed at room temperature using the Renishaw inVia Reflex system with a 532 nm laser. All spectra were recorded using a power of ∼1 mW with the samples sealed between two thin glass plates.

UV-Vis spectroscopy (Lambda 19, PerkinElmer) and transmission electron microscopy (TEM, JEOL JEM-1011 operating at 100 kV) were used to characterize the optical response, structure, and size of the nanoparticles during the functionalization process. To characterize the codification process, SERS spectra were collected in backscattering geometry with a Renishaw Invia Reflex system equipped with a 2D-CCD detector. The spectrograph used a high resolution grating (1200 g cm⁻¹) with additional band-pass filter optics. A 785 nm diode laser was focused onto the colloidal solution ([Ag⁰] = 0.1 mM) by a long-working distance objective (0.17 NA, working distance 30 mm). The spectra were acquired with an exposure time of 100 ms (depending on Raman intensity saturation) and a laser power at the sample of ca. 300 mW.

Optical microscope (OM) images of MoS₂ domains were observed using the Nikon Eclipse Ti-U (Nikon, Tokyo, Japan) and Mshot MJ30 (Mshot, Guangzhou, China). Scanning electron microscopy (SEM) images were acquired using a FEI Quanta 450. Raman (FEI Quanta, Hillsboro, OR, USA) and photoluminescence (PL) spectroscopy were performed using a Renishaw inVia Reflex system (Renishaw, Wharton Andech, UK) with a Leica dark-field microscope. The wavelength of the excitation laser was 532 nm, and the focus diameter was approximately 1 μm. The surface feature and film thickness of MoS₂ domains were measured by an atomic force microscope (AFM, NTEGRA Spectra, NT-MDT, Moscow, Russia).

SEM images were obtained using a JSM-6510LV and a JEM-2100F microscope (JEOL, Tokyo, Japan). TEM images were recorded by a Talos F200x electron microscope (FEI Co., USA). XRD (D8A25; Bruker, Germany) was used to determine the crystal structure of the samples. XPS (ESCALAB 250Xi; Thermo Scientific, USA) was employed to disclose the surface elemental compositions of the samples. UPS was measured using an ESCALAB 250Xi instrument with a monochromatic He I light source (21.2 eV). An InVia reflex system (Renishaw) operating at 532 nm was employed to obtain Raman spectra. The JC2000D Contact Angle System (POWEREACH, China) was used to measure the water contact angles of the samples at room temperature. A UV-Vis-NIR spectrometer (UV-3600; Shimadzu, Tokyo, Japan) was used to obtain the spectra of samples.