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2D semiconducting nanosheets have emerged as versatile platforms for electronics and energy conversion due to their diverse compositions and excellent physicochemical properties. A precise understanding of their electronic structures is essential for optimizing career transport and light energy conversion efficiency; however, experimental insights into the detailed band structures remain limited. In this study, the electronic structures of titanium oxide and nitrogen‐doped titanium oxide nanosheets are investigated as a model case. To clarify the effects of nitrogen doping, an alternative precursor is employed that enables the formation of nanosheets with enhanced nitrogen content compared to previously reported methods. The electronic structures of both titania and nitrogen‐doped titania nanosheets are elucidated using ultraviolet photoelectron spectroscopy (UPS) and low‐energy inverse photoelectron spectroscopy (LEIPS). The results clearly demonstrated that nitrogen incorporation induces both donor level formation and valence band modulation, leading to bandgap narrowing and an upward shift of the Fermi level. These findings provide comprehensive insights into the electronic structures of semiconducting nanosheets and reveal how anion doping modulates their band characteristics. This study successfully elucidates the electronic structures of inorganic semiconducting nanosheets using a combined UPS and LEIPS approach. Nitrogen‐doped titania nanosheets, synthesized via a pentatitanate route, exhibit bandgap narrowing and Fermi level modulation. The work demonstrates the effectiveness of UPS and LEIPS in directly probing band edges and donor states in 2D oxide semiconductors.

Graphene‐like materials are of interest for large‐scale hydrogen storage applications due to their lightweight, durable, and scalable properties. Nitrogen‐doping minimizes kinetic limitations in diffusion and recombination on surfaces, however, the role of graphitic nitrogen (GN) and pyridinic nitrogen (PN) is not well understood. Nitrogen‐doped graphene is synthesized on Ru(0001) using chemical vapor deposition (CVD) of pyridine and ion irradiation. Scanning tunneling microscopy (STM), x‐ray photoelectron spectroscopy (XPS), and density functional theory (DFT) are used to identify the structure, location, and thermodynamic stability of nitrogen species within the graphene moiré. CVD of pyridine results in a low nitrogen concentration (<0.1at%), while the post‐growth nitrogen ion irradiation allows us to increase the concentration further. The concentration of GN and PN is controlled by varying the ion dose and annealing temperature. Comparison of measured and simulated STM images of GN and PN yield an excellent agreement, allowing us to confidently establish that GN is preferentially located near the center of the Atop region, while PN is located in the valley region of the graphene moiré. This report explicitly confirms the site assignments and provides a foundation for the site synthesis and analysis of structural and electronic properties that drive the reactivity of N‐doped graphene. Nitrogen doping on Ru(0001) is investigated using ion implantation and annealing, tuning the distribution of graphitic (GN) and pyridinic (PN) nitrogen sites. STM, XPS, and DFT identified the structure and site distribution, and a thermodynamic phase diagram showed that GN is most stable at the Atop region, while PN preferred boundaries between FCC and HCP regions of the graphene moiré.

In this work, the impact of nitrogen doping (N-doping) on the distribution of sub-gap states in amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) is qualitatively analyzed by technology computer-aided design (TCAD) simulation. According to the experimental characteristics, the numerical simulation results reveal that the interface trap states, bulk tail states, and deep-level sub-gap defect states originating from oxygen-vacancy- (Vo) related defects can be suppressed by an appropriate amount of N dopant. Correspondingly, the electrical properties and reliability of the a-IGZO TFTs are dramatically enhanced. In contrast, it is observed that the interfacial and deep-level sub-gap defects are increased when the a-IGZO TFT is doped with excess nitrogen, which results in the degeneration of the device’s performance and reliability. Moreover, it is found that tail-distributed acceptor-like N-related defects have been induced by excess N-doping, which is supported by the additional subthreshold slope degradation in the a-IGZO TFT.

Selective adsorption of heavy metal ions from industrial effluent is important for healthy ecosystem development. However, the selective adsorption of heavy metal pollutants by biochar using lignin as raw material is still a challenge. In this paper, the lignin carbon material (N-BLC) was synthesized by a one-step hydrothermal carbonization method using paper black liquor (BL) as raw material and triethylene diamine (TEDA) as nitrogen source. N-BLC (2:1) showed excellent selectivity for Cr(VI) in the binary system, and the adsorption amounts of Cr(VI) in the binary system were all greater than 150 mg/g, but the adsorption amounts of Ca(II), Mg(II), and Zn(II) were only 19.3, 25.5, and 6.3 mg/g, respectively. The separation factor (SF) for Cr(VI) adsorption was as high as 120.0. Meanwhile, FTIR, elemental analysis and XPS proved that the surface of N-BLC (2:1) contained many N– and O– containing groups which were favorable for the removal of Cr(VI). The adsorption of N-BLC (2:1) followed the Langmuir model and its maximum theoretical adsorption amount was 618.4 mg/g. After 5th recycling, the adsorption amount of Cr(VI) by N-BLC (2:1) decreased about 15%, showing a good regeneration ability. Therefore, N-BLC (2:1) is a highly efficient, selective and reusable Cr(VI) adsorbent with wide application prospects.

Copper (Cu) is widely used as an industrial electrode due to its high electrical conductivity, mechanical properties, and cost‐effectiveness. However, Cu is susceptible to corrosion, which degrades device performance over time. Although various methods (alloying, physical passivation, surface treatment, etc.) are introduced to address the corrosion issue, they can cause decreased conductivity or vertical insulation. Here, using the nitrogen‐doped amorphous carbon (a‐C:N) thin film is proposed as a substrate on which Cu is directly deposited. This simple method significantly inhibits corrosion of ultrathin Cu (<20 nm) films in humid conditions, enabling the fabrication of ultrathin electronic circuit boards without corrosion under ambient conditions. This study investigates the origin of corrosion resistance through comprehensive microscopic/spectroscopic characterizations and density‐functional theory (DFT) calculations: i) diffusion of Cu atoms into the a‐C:N driven by stable C‐Cu‐N bond formation, ii) diffusion of N atoms from the a‐C:N to the Cu layer heading the top surface, which is the thermodynamically preferred location for N, and iii) the doped N atoms in Cu layer suppress the inclusion of O into the Cu lattice. By leveraging the ultrathinness and deformability of the circuit board, a transparent electrode and a crumpleable LED lighting device are demonstrated. Through the synergistic effect of the strong C‐Cu‐N bond formation facilitated by the diffused Cu in the N‐doped amorphous carbon (a‐C:N) and the inhibition of Cu vacancy formation by the diffused N in the Cu layer, ultrathin Cu films deposited on the a‐C:N film substrate are corrosion‐resistant. The Cu/a‐C:N thin film is used as an electronic circuit board for crumpled devices.

A high specific capacity conducting reduced graphene oxide nanosulfur nanocomposite (RGOSNC) cathode is synthesized via deposition of nanosulfur on graphene oxide (GO) through the hydrothermal treatment in the presence of multifaceted ethylenediamine (EDA) for improving the performance of lithium‐sulfur battery (LiSB). The maximum utilization of active material (sulfur) is facilitated by the attachment of nanosulfur to GO via EDA, and further, optimum reduction of GO into conducting, porous and interconnected RGO is performed via hydrothermal treatment in the available solution having residual EDA. Therefore, GO is reduced in highly conducting RGO without the use of any external reducing agent; minimizing the chance of impurity in the synthesized RGOSNC. A three‐dimensional interconnected porous conducting architecture with nitrogen (heteroatom) doping in RGO of RGOSNC with conductivity ∼1.83 S/cm assists easy electron transportation through conducting RGO network and stabilizes intermediate polysulfide to prevent loss of active material during the electrochemical performance. The synthesized RGOSNC cathode material delivers high initial specific capacities 1448 and 1040 mAh/g at 0.1 and 0.5 C, respectively. Prepared LiSB maintains ∼741 mAh/g retention over 100 cycles at 0.5 C with excellent Coulombic efficiency (∼99%).

Biomass-derived activated carbon materials with hierarchically nanoporous structures containing nitrogen functionalities show excellent electrochemical performances and are explored extensively in energy storage and conversion applications. Here, we report the electrochemical supercapacitance performances of the nitrogen-doped activated carbon materials with an ultrahigh surface area prepared by the potassium hydroxide (KOH) activation of the Nelumbo nucifera (Lotus) seed in an aqueous electrolyte solution (1 M sulfuric acid: H2SO4) in a three-electrode cell. The specific surface areas and pore volumes of Lotus-seed–derived carbon materials carbonized at a different temperatures, from 600 to 1000 °C, are found in the range of 1059.6 to 2489.6 m2 g−1 and 0.819 to 2.384 cm3 g−1, respectively. The carbons are amorphous materials with a partial graphitic structure with a maximum of 3.28 atom% nitrogen content and possess hierarchically micro- and mesoporous structures. The supercapacitor electrode prepared from the best sample showed excellent electrical double-layer capacitor performance, and the electrode achieved a high specific capacitance of ca. 379.2 F g−1 at 1 A g−1 current density. Additionally, the electrode shows a high rate performance, sustaining 65.9% capacitance retention at a high current density of 50 A g−1, followed by an extraordinary long cycle life without any capacitance loss after 10,000 subsequent charging/discharging cycles. The electrochemical results demonstrate that Nelumbo nucifera seed–derived hierarchically porous carbon with nitrogen functionality would have a significant probability as an electrical double-layer capacitor electrode material for the high-performance supercapacitor applications.

In this work, nitrogen-doped ZnO nanoparticles were synthesized in various conditions by the gas evaporation method with DC arc plasma. Nitrogen concentrations of 6.38 × 1018 cm−3 to 2.6 × 1019 cm−3 were obtained at a chamber pressure of 150 torr, using arc currents of 20 A to 70 A. The intensities of local vibrational modes at 275 cm−1 and 581 cm−1 in the Raman spectra of ZnO nanoparticles showed a dependency on the nitrogen concentration in the ZnO nanoparticles. The ratios of donor–acceptor pair and exciton emissions in the photoluminescence spectra of nitrogen-doped ZnO nanoparticles, and the electroluminescence of light-emitting diodes based on these nanoparticles, were nearly proportional to the Raman peak’s intensity at 275 cm−1. The results indicated that the nitrogen dopants in the ZnO nanoparticles were acting as an acceptor.

The fabrication of ZnO nanoparticles (NPs) was monitored and studied in situ by controlling the plasma parameters of the direct current (DC) arc plasma system, such as the current density and chamber pressure. The optical emission signature of nitrogen was spectroscopically studied using optical emission spectroscopy (OES) techniques, and it showed a dependency on the nitrogen concentration in the ZnO nanoparticles in relation to the output of the ZnO NPs-based homojunction light-emitting diodes (LEDs). The synthesized NPs had a good crystalline quality and hexagonal wurtzite structure, and they were characterized by X-ray diffraction (XRD) techniques and scanning electron microscope (SEM). The photoluminescence properties of the ZnO NPs and the optical and electrical parameters of the LEDs were also analyzed and correlated. The results indicate that the nitrogen dopants act as acceptors in the ZnO NPs and are favored in low plasma temperatures during fabrication. We anticipate that the results can provide an effective way to realize reliable nitrogen-doped p-type ZnO and tremendously encourage the development of low-dimensional ZnO homojunction LEDs.

Recently, nitrogen‐doped carbon materials have proved to be effective catalytic platforms for the oxygen reduction reaction (ORR). Despite the recent synthetic advances for the preparation of nitrogen‐incorporated carbon materials, the low‐temperature and water‐based synthesis of nitrogen‐doped carbon materials has rarely been explored due to the difficulties in nitrogen‐doping under such mild conditions. Here, nitrogen‐doped Pt/C (Pt/NC) catalysts are prepared using a facile, low‐temperature, aqueous‐phase method. Hydrazine treatment of a Pt/C catalyst successfully yields Pt/NC with controlled nitrogen content. The as‐prepared Pt/NC catalysts exhibit enhanced electrocatalytic activity and stability toward ORR in comparison to nitrogen‐free Pt/C, and their ORR activities are highly dependent on the level of nitrogen‐doping. The Pt/NC catalyst containing 2.0 at % nitrogen results in the largest improvement of ORR activity. It's all about the levels: Hydrazine treatment of a Pt/C catalyst successfully yielded nitrogen‐doped Pt/C (Pt/NC) with controlled nitrogen content. The as‐prepared Pt/NC catalysts exhibited enhanced electrocatalytic activity and stability toward the oxygen reduction reaction (ORR), and the corresponding ORR activity is highly dependent on the level of nitrogen‐doping (see figure; RHE=reversible hydrogen electrode).