Quanta 250 microscope

Scanning electron microscopy (SEM) images were collected on an FEI Quanta 250 microscope. Transmission electron microscopy (TEM), high-resolution TEM (HRTEM) images and selected area electron diffraction (SAED) patterns were recorded on an FEI Tecnai G2 F20 field-emission microscope. X-ray diffraction (XRD) patterns were obtained on a Bruker D8 ADVANCE diffractometer equipped with a CuK_α radiation source (λ = 1.54178 Å). Raman spectra were obtained on a Bruker Senterra confocal Raman spectrometer (λ_ex = 532 nm). N₂ adsorption/desorption isotherms at 77 K were carried out on a Quantachrome Autosorb-iQ instrument. Brunauer–Emmett–Teller (BET) specific surface areas were calculated from the linear range of the BET plot and pore width distribution curves were obtained using the quenched solid density functional theory (DFT) method. X-ray photoelectron spectroscopy (XPS) results were acquired on a Thermo Fisher ESCALAB 250Xi spectroscope with an excitation source of AlK_α radiation (1486.6 eV).

Pore textural properties were acquired using a Quantachrome Autosorb iQ by the N₂ isothermal adsorption–desorption method at 77 K. Brunauer–Emmett–Teller (BET) specific surface areas were obtained from the multi-point BET-plot calculation provided by the ASiQwin software (version 5.2). Pore size distribution curves, together with pore volumes and surface areas of pores with size between 0.5–50 nm, were calculated by the quenched solid density functional theory (DFT) method. Energy disperse spectroscopy (EDS) analyses were obtained from an FEI Quanta 250 microscope. Transmission electron microscope (TEM) images were recorded on an FEI Tecnai G2 F20 field-emission microscope. X-ray diffraction (XRD) patterns were collected on a Bruker D8 ADVANCE diffractometer equipped with a CuK_α radiation source (λ = 1.54178 Å). Raman spectroscopy analyses were acquired on a Bruker Senterra confocal Raman spectrometer (laser excitation wavelength: 532 nm). X-ray photoelectron spectroscopy (XPS) results were recorded on a Thermo Fisher ESCALAB 250Xi spectroscope excited by AlK_α radiation (1486.6 eV).

The surface corrosion (Test 2) and coupon weight loss were analyzed. To remove any adherent bacteria, the coupons were scraped with a sterile wooden stick in sterile glass bottles with 9 mL of a reducing solution. For the weight loss test, the coupon surfaces were cleaned (washed in acid, neutralized with sodium bicarbonate, rinsed in water and acetone, and dried in an air stream) as described by Nemati et al.¹⁵ (link) The determination of the exact weight of the coupons was carried out just before starting and after finishing the experiments. The coupon weight (in grams) was determined by using an electronic balance (Bioprecisa, model FA2104N). To calculate the weight loss resulting from corrosion, the weight of the coupon at the end of the experiments and after cleaning was subtracted from the original weight of the coupon. The corrosion rate (CR) of carbon steel coupons for each experiment (including the controls) was calculated and is expressed in mm/year,³¹ using 7.84 g/cm³ as the density of carbon steel. A two-sample t test was performed on the treated and control coupons.³² In addition, after the coupon surfaces were scraped and cleaned,¹⁵ (link) they were gold coated and examined by SEM (FEI QUANTA 250 microscope) to observe their corrosion patterns. The images were acquired at a resolution of 7192 × 3090 pixels.