Bridging the g‑C₃N₄ Interlayers for Enhanced Photocatalysis

Graphitic carbon nitride (g-C₃N₄) has been widely investigated and applied in photocatalysis and catalysis, but its performance is still unsatisfactory. Here, we demonstrated that K-doped g-C₃N₄ with a unique electronic structure possessed highly enhanced visible-light photocatalytic performance for NO removal, which was superior to Na-doped g-C₃N₄. DFT calculations revealed that K or Na doping can narrow the bandgap of g-C₃N₄. K atoms, intercalated into the g-C₃N₄ interlayer via bridging the layers, could decrease the electronic localization and extend the π conjugated system, whereas Na atoms tended to be doped into the CN planes and increased the in-planar electron density. On the basis of theoretical calculation results, we synthesized K-doped g-C₃N₄ and Na-doped g-C₃N₄ by a facile thermal polymerization method. Consistent with the theoretical prediction, it was found that K was intercalated into the space between the g-C₃N₄ layers. The K-intercalated g-C₃N₄ sample showed increased visible-light absorption, efficient separation of charge carriers, and strong oxidation capability, benefiting from the narrowed band gap, extended π conjugated systems, and positive-shifted valence band position, respectively. Despite that the Na-doped g-C₃N₄ exhibited narrowed bandgap, the high recombination rate of carriers resulted in the reduced photocatalytic performance. Our discovery provides a promising route to manipulate the photocatalytic activity simply by introducing K atoms in the interlayer and gains a deep understanding of doping chemistry with congeners. The present work could provide new insights into the mechanistic understanding and the design of electronically optimized layered photocatalysts for enhanced solar energy conversion

Optimizing Electrolyte Physiochemical Properties toward 2.8 V Aqueous Supercapacitor

Achieving a wide potential window of aqueous supercapacitor has been one of the key research interests to address its poor energy density. However, in this process, water decomposition becomes an increasingly significant issue that has to be tackled in order to attain a reliable aqueous supercapacitor. In order to avoid possible water decomposition at a wide potential, benign interaction between electrolyte and electrode during the cell operation has to be considered. In this work, a water-in-bisalt electrolyte consisting of 21 M lithium bis­(trifluoromethane)­sulfonamide and 1 M lithium sulfate was proposed. To complement the electrolyte, Li⁺ inserted MnO₂ and carbon were selected as electrode materials due to their low oxygen evolution reaction/hydrogen evolution reaction activities. The resultant aqueous supercapacitor was able to operate at 2.8 V which, to the best of our knowledge, is one of the widest potential windows reported for an aqueous supercapacitor system. The cell was able to deliver an energy density of 55.7 Wh kg^–1 at power density of 1 kW kg^–1, while attaining a good cyclic stability of 84.6% retention after 10000 cycles at a current density of 30 A g^–1. Such a strategy may be effective in the design of wide potential aqueous supercapacitors, which is crucial toward future supercapacitor development

Table1_Identification of a novel ANK1 gene variant c.1504-9G>A and its mechanism of intron retention in hereditary spherocytosis.DOCX

Objective: The objective of this study was to pinpoint pathogenic genes and assess the mutagenic pathogenicity in two pediatric patients with hereditary spherocytosis.Methods: We utilized whole-exome sequencing (WES) for individual analysis (case 1) and family-based trio analysis (case 2). The significance of the intronic mutation was validated through a Minigene splicing assay and supported by subsequent in vitro experiments.Results: Both probands received a diagnosis of hereditary spherocytosis. WES identified a novel ANK1 c.1504-9G>A mutation in both patients, causing the retention of seven nucleotides at the 5′ end of intron 13, as substantiated by the Minigene assay. This variant results in a premature stop codon and the production of a truncated protein. In vitro studies indicated a reduced expression of the ANK1 gene.Conclusion: The novel ANK1 c.1504-9G>A variant is established as the causative factor for hereditary spherocytosis, with the c.1504-9G site functioning as a splicing receptor.</p

In Situ Construction of g‑C₃N₄/g‑C₃N₄ Metal-Free Heterojunction for Enhanced Visible-Light Photocatalysis

The photocatalytic performance of the star photocatalyst g-C₃N₄ was restricted by the low efficiency because of the fast charge recombination. The present work developed a facile in situ method to construct g-C₃N₄/g-C₃N₄ metal-free isotype heterojunction with molecular composite precursors with the aim to greatly promote the charge separation. Considering the fact that g-C₃N₄ samples prepared from urea and thiourea separately have different band structure, the molecular composite precursors of urea and thiourea were treated simultaneously under the same thermal conditions, in situ creating a novel layered g-C₃N₄/g-C₃N₄ metal-free heterojunction (g-g CN heterojunction). This synthesis method is facile, economic, and environmentally benign using easily available earth-abundant green precursors. The confirmation of isotype g-g CN heterojunction was based on XRD, HRTEM, valence band XPS, ns-level PL, photocurrent, and EIS measurement. Upon visible-light irradiation, the photogenerated electrons transfer from g-C₃N₄ (thiourea) to g-C₃N₄ (urea) driven by the conduction band offset of 0.10 eV, whereas the photogenerated holes transfer from g-C₃N₄ (urea) to g-C₃N₄ (thiourea) driven by the valence band offset of 0.40 eV. The potential difference between the two g-C₃N₄ components in the heterojunction is the main driving force for efficient charge separation and transfer. For the removal of NO in air, the g-g CN heterojunction exhibited significantly enhanced visible light photocatalytic activity over g-C₃N₄ alone and physical mixture of g-C₃N₄ samples. The enhanced photocatalytic performance of g-g CN isotype heterojunction can be directly ascribed to efficient charge separation and transfer across the heterojunction interface as well as prolonged lifetime of charge carriers. This work demonstrated that rational design and construction of isotype heterojunction could open up a new avenue for the development of new efficient visible-light photocatalysts