Leo 1430vp

Fragments (1 cm²) of fresh leaves from the middle part and the edge of the leaf blade were set on 2 cm × 4 cm copper plates. To obtain a greater detail of the microstructure at high magnifications, the samples were frozen on a massive metal holder at −20 °C. Then, the plate with a fresh sample was fixed on the cooling stage of the Deben Coolstage refrigerating unit (UK) at −30 °C. The samples were imaged by a LEO-1430 VP (Carl Zeiss, Berlin, Germany) scanning electron microscope in high vacuum mode operating at 20 kV with a backscattered electron detector QBSD and a working distance of 8–12 mm (cryoSEM).

X-ray diffraction analysis was performed to identify carbonation products using an X-ray powder diffractometer (D8 Advance, Bruker, Germany). For all materials, two samples were analyzed under the following experimental conditions: Cu Kα radiation (λ = 0.154 nm), scanning range of 10°–70° and a scanning rate of 2.0°/min. The mineral phase composition was determined via thermal stability analysis (TG-DTG) using a simultaneous thermogravimetric analyzer (STA 7300, Hitachi, Japan) with 10 mg of sample analyzed at a temperature range from ambient temperature to 900 °C at a heating rate of 10 °C/min in a single measurement, as variations in outcome were expected to be small^{15 (link)}. A scanning electron microscope (LEO 1430VP, Carl Zeiss, Germany) was used at an accelerating voltage of 15 kV to analyze the micro-morphology of samples, which were sprayed with gold before the test to stabilize images. Analysis of the microstructure changes during C₂S and C₃S carbonation was carried out via ²⁹Si NMR analysis (600 M spectrometer, Agilent, US), with a 4-mm ZrO2 rotor at a rotation speed of 8 kHz and TMS solution as a ²⁹Si chemical shift calibration reference.

Characterizations of the ZnO NPs samples were recorded by using various techniques, including X-ray diffraction (XRD) (D2-Phaser, Brucker, Karlsruhe, Germany) with 2 theta from 20° to 80°; Fourier transform infrared spectroscopy (FTIR) (Spectrum Two, PerkinElmer, Shelton, CT, USA) at a wavenumber band of 4000–400 cm⁻¹; scanning electron microscopy (SEM) (Leo 1430VP, Carl Zeiss AG, Jena, Germany) [15 (link)] and field emission scanning electron microscopy (FE–SEM) (Regulus 8100, Hitachi Hight-Tech Corporation, Tokyo, Japan); integrated, energy dispersive X-ray spectroscopy (EDS), using the Bruker Xflash 6130 probe (Bruker, Billerica, MA, USA); Brunauer–Emmett–Teller (BET) surface area analysis (TriStar 3000 V6.07, Micromeritics Instrument Corporation, Norcross, GA, USA); ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis-DRS) (Scinco 4100, Shimadzu, Kyoto, Japan), in the wavelength ranging from 250 nm to 700 nm, step 0.5 nm using cm⁻¹ quartz cuvettes, step 0.5 nm [22 (link)]; and photoluminescence (PL) (FLS 1000, Edinburgh Instruments Ltd., Livingston, West Lothian, UK) within the wavelength ranges of 375 nm to 800 nm (step 1 nm) were obtained under the 325 nm line of Xe laser excitation [29 ].