Refernces
10.1039/c3ce42654h
The study examines the adsorption and photocatalytic performance of bismuth oxyiodide (BiOI) for the degradation of three dyes: methyl orange (MO), Rhodamine B (RhB), and methylene blue (MB). The adsorption performance of BiOI was found to vary depending on the dye, with the order of adsorption efficiency being MO < RhB < MB. This trend was attributed to the electrostatic interactions between the positively charged RhB and MB dyes and the negatively charged BiOI surface, while MO, being negatively charged, interacted less favorably. Under UV and visible light irradiation, the photocatalytic degradation of MO followed the order BiOI < Ag–BiOI < Ti–BiOI, indicating that Ti-doping enhanced the photocatalytic activity. For RhB, BiOI alone was more effective under UV light, but Ag and Ti-doped BiOI showed better performance under visible light, suggesting a dye-sensitized mechanism where the dye absorbs light and transfers energy to the catalyst. Methylene blue (MB), despite being efficiently adsorbed, showed poor photocatalytic degradation under both UV and visible light, indicating that its removal was primarily through adsorption rather than photocatalysis. The study also identified superoxide radicals (?O2 -) and holes (h+) as the active species responsible for dye degradation under visible light, with no significant contribution from hydroxyl radicals (?OH). These findings highlight the complex interplay between adsorption and photocatalytic mechanisms in BiOI and its doped variants for dye degradation.
10.1021/jo00298a049
The research focuses on the synthesis and investigation of the reactivity of two phenanthroline-linked dihydronicotinamides, compounds 3 and 6, which serve as models for the NADH-alcohol dehydrogenase coenzyme-enzyme complex. The purpose of this study was to examine whether the metal ion in these models could mimic the function of catalytic zinc in alcohol dehydrogenase, specifically in binding the substrate near the dihydronicotinamide group, orienting the groups for hydride transfer, and activating the carbonyl group for reduction. The researchers concluded that the metal ion in these models, particularly when Zn2+ is present, could effectively mimic the catalytic function of zinc in the enzyme complex, with hydride transfer occurring within a ternary complex. Key chemicals used in the process include 1,4-dihydro-l-(l,l0-phenanthrolin-2-ylmethyl)-3-pyridinecarboxamide (3), 1,4-dihydro-N-(l,l0-phenanthrolin-2-ylmethyl)-l-(phenylmethyl)-3-pyridinecarboxamide (6), 2,4,6-trinitrobenzene sulfonate (TNBS), methylene blue (MB+), and 2-pyridinecarboxaldehyde (PyCHO), along with various metal ions (M2+ = Zn2+, Co2+, Ni2+, Mg2+, and Cd2+).
10.1016/S0040-4020(01)96029-6
The research investigates the photooxygenation of pteridin-2,4,7-triones, focusing on synthesizing and examining the thermal reactions of pteridin-2,4,7-trione 6,8'-endoperoxides. The study aims to explore the reactivity of these endoperoxides and their potential as sources of singlet oxygen. Key chemicals include pteridin-2,4,7-triones (1), which react with singlet oxygen to form stable endoperoxides (2-5). Dye-sensitized photooxygenation using sensitizers like rose bengal and methylene blue in solvents such as dichloromethane and methanol is employed to produce these endoperoxides. The endoperoxide (2a) is found to revert to the starting pteridin-2,4,7-trione (la) upon heating, liberating singlet oxygen, confirmed by trapping experiments with various singlet oxygen acceptors. The study concludes that pteridin-2,4,7-trione endoperoxides can serve as effective singlet oxygen generators, offering a stable and storable means of producing singlet oxygen for chemical applications. In the research, rose bengal and methylene blue serve as sensitizers in the dye-sensitized photooxygenation process. Their primary role is to facilitate the reaction of pteridin-2,4,7-triones with singlet oxygen, enhancing the efficiency of endoperoxide formation. Specifically, these dyes absorb visible light and transfer the energy to molecular oxygen, generating singlet oxygen, which then reacts with the pteridin-2,4,7-triones to form the desired endoperoxides.
Xn
