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1.
Langmuir ; 39(42): 15055-15066, 2023 Oct 24.
Article in English | MEDLINE | ID: mdl-37842923

ABSTRACT

Compositional and structural elucidation of the materials is important to know their properties, chemical stability, and electro-photoactivity. The heterojunction electrocatalyst and photocatalyst activity could open a new window for solving the most urgent environmental and energy problems. Here, for the first time, we have designed and fabricated Bi2O3/bismuth titanates modified with MOF-In2S3/CdIn2S4 materials by a stepwise process. The detailed structural elucidation and formation of mixed composite phases were studied in detail. It has been found that the formed composite was efficiently utilized for the electrocatalytic H2 production reaction and the photocatalytic degradation of tetracycline. XRD patterns for the metal-organic framework-In2S3 showed a main compound of MOF, and it was assigned to a MIL-53 MOF phase, with a monoclinic structure. The addition of CdCl2 onto the MOF-In2S3 phase effectively produced a CdIn2S4 flower platform on the MOF rods. The uniform dispersion of the bismuth titanates in MOF-In2S3/CdIn2S4 materials is detected by mapping of elements obtained by dark-field HAADF-STEM. Finally, the predictions of how to integrate experiments and obtain structural results more effectively and their common development in new heterojunctions for electro-/photocatalytic applications are presented.

2.
Chemosphere ; 306: 135659, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35820480

ABSTRACT

Novel KTO/BiOCl nanostructured photocatalysts with various weight proportions were synthesized using a simple hydrothermal process. The as-prepared nanostructured composite catalysts were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, UV-vis diffused reflectance spectroscopy, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy with high resolution, X-ray photoelectron spectroscopy, and photoluminescence (PL). The photocatalytic activity of prepared catalysts was examined using Rhodamine B (RhB) and Congo Red (CR) as the aimed pollutants. BiOCl nanoparticles were distributed uniformly on the surface of the K2Ti4O9 nanobelts. The optical properties showed that the layered titanate with BiOCl nanostructured photocatalyst displayed improved photoresponsivity due to the narrowed bandgap. The PL results showed that the greater inhibition of the electron-hole recombination process and KTO/BiOCl with a mass proportion of 20% revealed the most favorable photocatalytic behavior. The rate constant of RhB and CR degradation was five times as high as that of the bare BiOCl and titanate. The superior photocatalytic performance was attributed to the advancement of heterojunction between the KTO nanobelt and BiOCl. The KTO/BiOCl nanostructure is a promising visible, active photocatalyst, and the photocatalytic mechanism is discussed using the possible band structures of BiOCl and KTO.


Subject(s)
Coloring Agents , Nanostructures , Catalysis , Light , Nanostructures/chemistry , Photoelectron Spectroscopy
3.
J Nanosci Nanotechnol ; 21(6): 3183-3191, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-34739774

ABSTRACT

Here we reports an effective synthetic method for the preparation of N-graphene upon thermal annealing of prepared graphene oxide in the existence of ammonia. N-doped graphene oxide was analysed using different characterization techniques like X-ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The nitrogen atom showed good binding with the graphene sheets, that are analysed by the X-ray photoelectron spectroscopy. The synthesized N-graphene have shown higher thermal stability compared with GO and graphene. The elcerochemnical performance like Cyclic voltammetry as well chronopotentiometry charge-discharge calculations revealed that the N-doped graphene exhibits remarkable behaviour favors a specific capacitance value about 209 F g-1 at 5 mV s-1 and 270 F g-1 for 1 A g-1 applied current density including outsanding charge-discharge stability about 98% of the initial capacitance subsequent 1000 cycles at 5 A g-1. The N-content in the graphene material with the optimized reaction parameters potentially improved electrode active material for energy storage applications.

4.
J Nanosci Nanotechnol ; 19(11): 6965-6977, 2019 11 01.
Article in English | MEDLINE | ID: mdl-31039849

ABSTRACT

Value added chemicals, fuels, and fuel additives can be obtained from cheap bio masses such as levulinic acid. Levulinic acid is the dehydration and hydrolysis products of pentoses and hexoses. The present work deals with the synthesis of sulphobenzylated Al-SBA-15, [SO3H-Bz-Al-SBA-15], characterization by various analytical techniques such as XRD, BET, FT-IR, TGA, DTA, FE-SEM/EDS and HR-TEM/EDX techniques and evaluation of catalytic activity towards esterifi-cation of levulinic acid to ethyl levulinate under mild and non corrosive conditions. Sulphonation of the aromatic ring of the benzyl group has been done in different amounts to get nanoporous x% SO3H-Bz-Al-SBA-15 catalysts where (x ═ 0.02, 0.04, 0.06, 0.08 and 0.10% w/w). Among them 0.08% SO3H-Bz-Al-SBA-15 catalyst showed the highest conversion of levulinic acid (100%) with the highest selectivity towards ethyl levulinate (100%). Esterification of levulinic acid has been carried out with different primary alcohols and all of them yielded 100% selectivity towards alkyl levulinate. However conversion level of levulinic acid was found to be different with different alcohols. Reaction conditions have been optimized. The results were compared with other supported catalysts and discussed.

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