M4 tornado micro xrf spectrometer

For the elemental mapping of metal distribution within fronds, the sample plants were subjected to the same Cr(VI) and Ni treatments and placed under the same ambient conditions as described in Section 2.1. Prior to μXRF scanning, the plants were transferred from metal-containing medium to 50 mL Type I ultrapure water for 10 min in order to remove excess metals adhering to the external surface of fronds and roots. Following that, the roots were carefully removed, and the plants were air-dried for 3 days, while being gently pressed to prevent deformation of fronds.
µXRF investigations were carried out using a Bruker M4 TORNADO Micro-XRF spectrometer (Bruker, Billerica, MA, USA) using a Rh-tube without any filter, at 50 kV accelerating voltage and 400 µA current. Characteristic X-ray lines were recorded by two energy dispersive detectors. Each of the two Be-window silicon drift detectors had a 30 mm² active area. The mapping was performed in 20 mbar vacuum. The beam diameter was focused to 20 µm by the built-in polycapillary lens. The recorded rectangular maps were acquired with 100 ms/pixel velocity and two accumulations. For QMap analysis, the M4 TORNADO software (version: 1.6.621.0) was used.

The XRF technique determined the quantitative elemental analysis, purity, and percent stoichiometry of the synthesized mono-/bimetallic NP powder. The NP powder was directly cast on a silicon wafer to form a multilayer film. The XRF measurement was performed using an M4 TORNADO Micro-XRF spectrometer (Bruker Nano, Berlin, Germany) operating at 50 kV/600 µA (30 W), equipped with an X-Flash solid-state silicon drift detector (SSD) having an effective area of 30 mm² with a resolution of 135 eV. Advanced polycapillary X-ray optics were used, which reduces the X-ray spot size to 25 µm, ensuring very high excitation intensity. The data acquisition was performed at different positions on the coated film with an accumulation time of 60 s at each point.

X-ray diffraction profiles of the synthetized nanostructures were recorded by a Miniflex diffractometer (Rigaku, Tokyo, Japan) from 20 to 80°. The step was 0.020° and the scan speed 0.25°/min. A CuKα radiation at 30 kV and 100 mA was used as X-rays source.
The morphology of the synthesized structures was analyzed by a Field Emission Scanning Electron Microscope (FESEM) on a Sigma VP microscope (Zeiss, Oberkochen, Germany) equipped with a Gemini electron column.
To determine the stoichiometric ratio of Zn and Fe in the composite catalyst, X-Ray Fluorescence (XRF) spectroscopic measurements were performed by using a M4 TORNADO Micro-XRF spectrometer (Bruker, Billerica, MA, USA).
Brunauer−Emmett−Teller (BET) method was used to determine the specific surface area and porosity of the photocatalytic materials. The analysis was carried out by a Quantachrome NOVA 2200e series surface analyzer (Boynton Beach, FL, USA) using N₂ adsorption/desorption at 77 K. Before performing the measurements, the samples were degassed under a N₂ atmosphere for 12 h at 120 °C.