U 3310

To confirm the colloidal solution’s reduction in silver ions, a U.V.–visible spectroscopy (U-3310, Hitachi, Tokyo, Japan), was used to examine the U.V. spectrum of 1 mL of an aliquot sample in a quartz cuvette, scanning for wavelengths between 200 and 700 nanometers, in comparison to distilled water as a control and 1 mM AgNO₃ as a blank [67 (link)].

First, 1 mL aliquot of colloidal FeNPs solution in quartz cuvettes was evaluated using UV–visible spectroscopy (U-3310, Hitachi, Tokyo, Japan), using distilled water as a reference and 0.05 mM FeSO4 as a blank, to validate the reduction of the ferric ions in the colloidal solution [27 (link)].

Absorption spectra from 700 to 350 nm were measured at room temperature using a spectrophotometer (U3310, HITACHI) with an attachment for the cylindrical Raman spinning cell. The sample concentration and composition were determined as follows: complex IV concentration was determined for the reduced form using an extinction coefficient of ϵ_604–630 = 46.6 mm⁻¹ cm⁻¹ (29 (link)). Concentrations of c-type cytochrome and b-type cytochrome were determined on redox difference spectra using ϵ_553–544 = 19 mm⁻¹ cm⁻¹ and ϵ_562–577 = 20 mm⁻¹ cm⁻¹, respectively (30 (link)).

Compressive strength tests were carried out according to the methodology described in the standard CNS 382.R2002. As defined in CNS 9212. B7197, the constant loading rate was set as 1 mm/min.
The water absorption and bulk specific density tests, based on Archimedes’ principle, were conducted according to CNS 619.R3013.
The water absorption ( $$A_W$$ ) was calculated as follows: $$A_W(\%)=\frac{W_3-W_1}{W_3-W_2}\times 100$$
The bulk specific density ( $$D_b$$ ) was calculated as follows: $$A_W(\%)=\frac{W_3-W_1}{W_3-W_2}\times 100$$
where W1 denotes the weight of the specimen after complete drying at 105–120 °C, W2 represents the weight of the specimen after 24 h of soaking, and W3 indicates the saturation weight of the specimen.
The test results of compressive strength, flexural strength, and physical properties were all obtained after averaging the test data of five specimens.
To investigate the LTGS bricks’ microstructure, crystal phase, and chemical properties, scanning electron microscopy (SEM/EDS) analysis, X-ray diffraction (XRD) analysis, and X-ray fluorescence (XRF) were performed. We performed SEM (ZEISS Gemini SEM500) at 0.02–30 kV; XRD (Hitachi U-3310) analysis was conducted with Cu Ka, λ = 1.54060 × 10⁻¹⁰ m radiation, at 30 kV, 10 mA, and 11.4°/min; and the XRF (Hitachi X-MET8000) by Pd target to identify the LTGS bricks.

The photocatalytic activity of the BiOBr_xI_1−x nanoplates for the degradation of RhB was evaluated using a 350 W Xe arc lamp (with a 420 nm cutoff filter) as the light source at ambient temperature. Before the tests, 10.0 mg BiOBr_xI_1−x samples were added into 30 mL aqueous solutions containing 20 mg L⁻¹ RhB and stirred in the dark for 30 min to ensure sufficient adsorption/desorption equilibrium. At specified time intervals, 1 mL of the samples was taken from the reaction system and centrifuged at 12000 rpm for 10 min to remove the photocatalyst particles. The RhB concentration solution was assayed with a UV-vis spectrometer (U-3310, Hitachi Co., Japan) by recording the variations of the light absorption at λ = 554 nm.

¹H NMR spectra were recorded on a 500 MHz Bruker Avance III HD spectrometer using CDCl₃ or DMSO-d6 as the solvent. FT-IR spectra of the samples were measured on an IRPrestige-21 instrument (Shimadzu, Japan) by a transmission method using the KBr pellet technique. Matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was performed on a Bruker autoflflex III (Bruker, Germany). Cyclic voltammetry (CV) measurements were performed with a CHI650E electrochemical workstation. The redox potentials of the dyes were measured in a DMF solution (3 × 10⁻⁴ M) containing 0.1 M tetrabutylammonium hexafluorophosphate (TBAPF6) as the supporting electrolyte at a scan rate of 100 mV s⁻¹, using AgCl/Ag and platinum wire as reference and counter electrodes, respectively. All potentials were calibrated with ferrocene/ferrocenium (Fc/Fc⁺) as an internal standard. UV-vis absorption spectra were collected using a UV-2550 spectrophotometer (Shimadzu, Japan). Photoluminescence (PL) and time-resolved fluorescence decay curves of the dyes in DMF solution (1 × 10⁻⁵ M) were obtained on a spectrophotometer of U-3310 (Hitachi, Japan).