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1. Effect of Carbon Doping on CO ₂ ‐Reduction Activity of Single Cobalt Sites in Graphitic Carbon Nitride

   https://doi.org/10.1002/cnma.202100164  

   Huang, Peipei; Huang, Jiahao; Li, Junying; Zhang, Lei; He, Jie; Caputo, Christine_A; Frenkel, Anatoly_I; Li, Gonghu (June 2021, ChemNanoMat)

   Abstract Single‐atom catalysts have demonstrated interesting activity in a variety of applications. In this study, we prepared single Co²⁺sites on graphitic carbon nitride (C₃N₄), which was doped with carbon for enhanced activity in visible‐light CO₂reduction. The synthesized materials were characterized with a variety of techniques, including microscopy, X‐ray powder diffraction, UV‐vis spectroscopy, infrared spectroscopy, photoluminescence spectroscopy, and X‐ray absorption spectroscopy. Doping C₃N₄with carbon was found to have profound effect on the photocatalytic activity of the single Co²⁺sites. At relatively low levels, carbon doping enhanced the photoresponse of C₃N₄in the visible region and improved charge separation upon photoactivation, thereby enhancing the photocatalytic activity. High levels of carbon doping were found to be detrimental to the photocatalytic activity of the single Co²⁺sites by altering the structure of C₃N₄and generating defect sites responsible for charge recombination. 

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2. Oxygen Incorporation in the Molecular Beam Epitaxy Growth of Sc _x Ga _1−x N and Sc _x Al _1−x N

   https://doi.org/10.1002/pssb.201900612  

   Casamento, Joseph; Xing, Huili Grace; Jena, Debdeep (January 2020, physica status solidi (b))

   Secondary‐ion mass spectrometry (SIMS) is used to determine impurity concentrations of carbon and oxygen in two scandium‐containing nitride semiconductor multilayer heterostructures: Sc_xGa_1−xN/GaN and Sc_xAl_1−xN/AlN grown by molecular beam epitaxy (MBE). In the Sc_xGa_1−xN/GaN heterostructure grown in metal‐rich conditions on GaN–SiC template substrates with Sc contents up to 28 at%, the oxygen concentration is found to be below 1 × 10¹⁹ cm⁻³, with an increase directly correlated with the scandium content. In the Sc_xAl_1−xN–AlN heterostructure grown in nitrogen‐rich conditions on AlN–Al₂O₃template substrates with Sc contents up to 26 at%, the oxygen concentration is found to be between 10¹⁹and 10²¹ cm⁻³, again directly correlated with the Sc content. The increase in oxygen and carbon takes place during the deposition of scandium‐alloyed layers. 

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3. Modeling thermocatalytic systems for CO ₂ hydrogenation to methanol

   https://doi.org/10.1039/D5SC00211G  

   Sun, Jikai; Wu, Jianzhong (April 2025, Chemical Science)

   The hydrogenation of CO₂to CH₃OH over Cu-based catalysts holds significant potential for advancing carbon sequestration and sustainable chemical processes. 

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4. A Photoionization Study on the Detection of 1‐Sila Glycolaldehyde (HSiOCH ₂ OH), 2‐Sila Acetic Acid (H ₃ SiCOOH), and 1,2‐Disila Acetaldehyde (HSiOSiH ₃ )

   https://doi.org/10.1002/chem.202004863  

   Chandra, Sankhabrata; Eckhardt, André_K; Turner, Andrew_M; Tarczay, György; Kaiser, Ralf_I (February 2021, Chemistry – A European Journal)

   Abstract The identification of silicon‐substituted, complex organics carrying multiple functional groups by classical infrared spectroscopy is challenging because the group frequencies of functional groups often overlap. Photoionization (PI) reflectron time‐of‐fight mass spectrometry (ReTOF‐MS) in combination with temperature‐programmed desorption (TPD) holds certain advantages because molecules are identified after sublimation from the matrix into in the gas phase based on distinct ionization energies and sublimation temperatures. In this study, we reveal the detection of 1‐silaglycolaldehyde (HSiOCH₂OH), 2‐sila‐acetic acid (H₃SiCOOH), and 1,2‐disila‐acetaldehyde (H₃SiSiHO)—the silicon analogues of the well‐known glycolaldehyde (HCOCH₂OH), acetic acid (H₃CCOOH), and acetaldehyde (H₃CCHO), in the gas phase after preparation in silane (SiH₄)–carbon dioxide ices exposed to energetic electrons and subliming the neutral reaction products formed within the ices into the gas phase. 

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5. What is the fate of xylem‐transported CO ₂ in Kranz‐type C ₄ plants?

   https://doi.org/10.1111/nph.15908  

   Stutz, Samantha S.; Hanson, David T. (June 2019, New Phytologist)

   Summary High concentrations of dissolved inorganic carbon in stems of herbaceous and woody C₃plants exit leaves in the dark. In the light, C₃species use a small portion of xylem‐transported CO₂for leaf photosynthesis. However, it is not known if xylem‐transported CO₂will exit leaves in the dark or be used for photosynthesis in the light in Kranz‐type C₄plants.Cut leaves ofAmaranthus hypochondriacuswere placed in one of three solutions of [NaH¹³CO₃] dissolved in KCl water to measure the efflux of xylem‐transported CO₂exiting the leaf in the dark or rates of assimilation of xylem‐transported CO₂* in the light, in real‐time, using a tunable diode laser absorption spectroscope.In the dark, the efflux of xylem‐transported CO₂increased with increasing rates of transpiration and [¹³CO₂*]; however, rates of¹³C_effluxinA. hypochondriacuswere lower compared to C₃species. In the light,A. hypochondriacusfixed nearly 75% of the xylem‐transported CO₂supplied to the leaf.Kranz anatomy and biochemistry likely influence the efflux of xylem‐transported CO₂out of cut leaves ofA. hypochondriacusin the dark, as well as the use of xylem‐transported CO₂* for photosynthesis in the light. Thus increasing the carbon use efficiency of Kranz‐type C₄species over C₃species. 

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