Gold nanoparticles deposited on TiO2 Degussa P25, prepared by deposition-precipitation with urea, were studied in the photocatalytic hydrogen production. The effect of parameters such as mass of catalyst, gold loading, thermal treatment, and atmosphere of treatment was evaluated and optimized. The presence of metallic gold on the titania surface showed to have contributed to the high improvement in the activity of bare TiO2 for hydrogen generation under UV light (λ=254 nm) using a lamp of low energy (2W) consumption. The optimal gold loading for the photocatalysts was 0.5 wt.%, the mass of catalyst in the reactor was 0.5 g/L in a water/methanol 1:1 vol. solution, and the thermal treatment that produced the most active gold nanoparticles was found at 300°C. The photocatalysts thermally treated under hydrogen at 300°C produced 1492 μmol g(-1)h(-1) of hydrogen; the same catalyst activated in air produced 1866 μmo lg(-1)h(-1) of hydrogen.
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http://dx.doi.org/10.1016/j.jhazmat.2013.03.057 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Nankai University, Department of Chemistry, Weijin road, 300071, Tianjin, CHINA.
Localized surface plasmon resonance (LSPR) metals exhibit remarkable light-absorbing property and unique catalytic activity, attracting significant attention in photocatalysts recently. However, the practical application of plasmonic nanometal is hindered by challenge of energetic electrons extraction and low selectivity. The energetic carriers generated in nanometal under illumination have extremely short lifetimes, leading to rapid energy loss.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, P. R. China.
As an efficient, sustainable, and environmentally friendly semiconductor material, covalent organic frameworks (COFs) can generate hydrogen peroxide (HO) by photocatalysis, attracting wide attention in recent years. Herein, the effects of hydroxyl, methoxyl, and vinyl groups of imide-linked two-dimensional (2D) COFs on the photocatalytic production of HO were studied theoretically and experimentally. The introduction of vinyl groups greatly promotes the photogenerated charge separation and migration of COFs, providing more oxygen adsorption sites, stronger proton affinity, and lower intermediate binding energy, which effectively facilitates the rapid conversion of oxygen to HO.
View Article and Find Full Text PDFJ Fluoresc
January 2025
Department of Stem Cell and Regenerative Medicine and Medical Biotechnology, Centre for Interdisciplinary Research, D. Y. Patil Education Society, Kolhapur, Maharashtra, India.
A straightforward one-step hydrothermal method is introduced for synthesizing highly efficient red fluorescence carbon dots (R-CQDs), utilizing Heena leaf (Lawsonia inermis) powder as the carbon precursor. The resulting R-CQDs exhibit excitation at 540 nm and emission at 675 nm, a high absolute photoluminescence (PL) with quantum yield of 40% in ethanol. Various physicochemical characterization was employed to confirm successful formation of R-CQDs including UV-Vis Spectroscopy, Fourier Transform Infrared (FT-IR) Spectroscopy, X-ray diffraction Spectroscopy, Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Chemistry, University of Toronto, Toronto, ON, Canada.
As the global quest for sustainable energy keeps rising, exploring novel efficient and practical photocatalysts remains a research and industrial urge. Particularly, metal organic frameworks were proven to contribute to various stages of the carbon cycle, from CO capture to its conversion. Herein, we report the photo-methanation activity of three isostructural, nickel-based metal organic frameworks incorporating additional niobium, iron, and aluminum sites, having demonstrated exceptional CO capture abilities from thin air in previous reports.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Research Center for Solar Energy Chemistry and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan.
Photocatalytic transformation of nitrate (NO) in wastewater into ammonia (NH) is a challenge in the detoxification and recycling of limited nitrogen resources. In particular, previously reported photocatalysts cannot promote the reaction using water as an electron donor. Herein, we report that copper-doped titanium dioxide (Cu-TiO) powders, prepared via the sol-gel method and subsequent calcination, promote NO-to-NH reduction in water.
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