pH-regulated hydrothermal synthesis and characterization of Sb₄O₅X₂ (X = Br/Cl) and its use for the dye degradation of methyl orange both with and without light illumination

Abstract

A pH-regulated hydrothermal synthesis method was employed to synthesize Sb4O5Br2 and Sb4O5Cl2 crystallites.

Zn3Sb4O6F6 and KI-Doped Zn3Sb4O6F6: A Metal Oxyfluoride System for Photocatalytic Activity, Knoevenagel Condensation, and Bacterial Disinfection

“…After reviewing the literature, ,− it could be proposed that the generation of several ROS like hydroxyl radicals or superoxide radical anions play the key role in dye degradation reactions. The probable mechanism (Figure ) in the presence of sunlight could be portrayed as follows: Zn 3 Sb 4 normalO 6 normalF 6 + h ν → Zn 3 Sb 4 normalO 6 normalF 6 0.25em ( e CB − + h VB + ) HO − + normalh VB + → HO · normalH 2 normalO + normalh VB + → HO · prefix+ normalH + normale CB − + normalO 2 → · normalO 2 − …”

“…The FTIR studies (Figure 7A) show a strong peak at 737 cm −1 , which corresponds to the Sb−O stretching frequency. 21 Zn(II)−O stretching frequency was observed at 670 cm −1 , which could be attributed to the octahedral geometry around Zn(II). 95,96 The Zn−F bond response was obtained 44 near 500 cm −1 .…”

“…Zn 3 Sb 4 O 6 F 6 crystallites (0.5 mg/mL solution) were introduced to the MB aqueous solution (10 mg/L), which was stirred magnetically at room temperature (27 °C) in the absence of light until the adsorption–desorption equilibrium was attained. After this, the solution was exposed to sunlight ,,, for 8 h while being constantly stirred. Approximately, 4 mL of solutions were taken from the mother solution at 1 h interval, and the degradation was monitored through UV–vis spectrophotometric measurement at a specific wavelength for each solution at different pH values.…”

“…Tuning of surface morphology by varying the pH of photocatalytic materials with semiconductor properties in order to observe the impact of light absorption ability is of particular relevance. 21 Photocatalytic reactions proceed through the numerous redox reactions initiated with the formation of electron−hole pairs by absorbing radiation (UV/UV−vis light), followed by active charge separation. The radiative or nonradiative electron and hole recombination occurs on the photocatalysts' surfaces.…”

“…Photocatalysts have lately acquired prominence as a research topic due to their wide variety of applications in fuel cells, harvesting energy, hydrogen production, , degrading organic pollutants into simple inorganic substances (CO 2 and H 2 O) with light irradiation, − and hence in waste water treatment. , Surface structure and morphology play an important role in photocatalysis − alike some important surface-dependent properties (e.g., sensors, actuators, etc. − ) of materials. Tuning of surface morphology by varying the pH of photocatalytic materials with semiconductor properties in order to observe the impact of light absorption ability is of particular relevance . Photocatalytic reactions proceed through the numerous redox reactions initiated with the formation of electron–hole pairs by absorbing radiation (UV/UV–vis light), followed by active charge separation.…”