The precise control of electronic structure in nitrogen-doped titanium dioxide (N-TiO2) is crucial for optimizing its optoelectronic performance. In this study, N-TiO2 films were prepared via an in-situ hydrothermal method by varying the urea concentrations. Surface-sensitive X-ray photoelectron (XPS) and high-brilliance synchrotron-based X-ray absorption (XAS) spectroscopy is employed to probe the electronic and local structural modifications. Despite an incremental change of urea concentration, the chemical state of Ti4+ state is preserved within the experimental conditions. This is possible since the stabilized oxygen vacancies is accessible by hosting electrons at the neighbouring Ti atoms, and altering the Ti–N/O bond geometries. The XAS further revealed distinct orbital features within the Ti L3-edge in which t2g and eg peak splitting are highlighted the D2d symmetry of anatase. The incorporation of nitrogen enhanced N 2p–O 2p hybridization, weakening Ti 3d–O 2p hybridization. The fluctuating trend in the area ratio of eg (dz2) orbital infers direct evidence of the electron redistribution within Ti 3d–O 2p orbitals along the z-axis. These findings were corroborated in a similar trend shown at the pre-edge features, indicating the unprecedented charge carrier dynamics in this doped TiO2 system. These synchrotron-based measurements unveil the electronic modifications of N-TiO2, paving the way for the rational design of tunable heteroatom-doped metal oxides materials.

Amidst the powerful capabilities of wastewater remediation using ozone nanobubbles (ONBs), the intricate challenge of pH control remains unsolved. To date, an efficient and scalable chemical agent is highly desired to overcome the limiting factor of conventional ozone-based wastewater conversion. This study introduces a sequential system that combines ONBs with adsorption techniques utilizing an eggshell-based adsorbent. The synergistic application of ONBs and adsorption successfully achieved notable removal percentages of 95.05% for turbidity, 96.18% for color at 418 nm, and 61.33% for TDS. In comparison, the individual ONB system showed removal percentages of 94.97%, 95.93%, and 61.97%, while the adsorption alone achieved 34.02, 29.65%, and 16.93%, respectively. Additionally, the combined system effectively neutralized the solution, increasing the pH from 2.67 to 7.14, outperforming both ONBs (pH 2.67) and adsorption (pH 6.89) alone. Our work underscores the efficiency of the system, which not only provides a high removal percentage of pollutants but also secures the required pH levels. This showcases a forward leap in developing environmentally friendly and efficient water treatment technologies.

In the past decades, the invention of scanning probe microscopy (SPM) as the versatile surface-based characterization of organic molecules has triggered significant interest throughout multidisciplinary fields. In particular, the bond-resolved imaging acquired by SPM techniques has extended its fundamental function of not only unraveling the chemical structure but also allowing us to resolve the structure−property relationship. Here, we present a systematical review on the history of chemical bonds imaged by means of noncontact atomic force microscopy (nc-AFM) and bond-resolved scanning tunnel-ing microscopy (BR-STM) techniques. We first summarize the advancement of real-space imaging of covalent bonds and the investigation of intermolecular noncovalent bonds. Beyond the bond imaging, we also highlight the applications of the bond-resolved SPM techniques such as on-surface synthesis, the determination of the reaction pathway, the identification of molecular configurations and unknown products, and the generation of artificial molecules created via tip manipulation. Lastly, we discuss the current status of SPM techniques and highlight several key technical challenges that must be solved in the coming years. In comparison to the existing reviews, this work invokes researchers from surface science, chemistry, condensed matter physics, and theoretical physics to uncover the bond-resolved SPM technique as an emerging tool in exploiting the molecule/surface system and their future applications.

Recent interest in two-dimensional (2D) lead-free hybrid organic–inorganic perovskites (HOIPs) has driven significant progress in the development of magnetic and electronic materials. Herein, we systematically compare a series of low-temperature growth of 2D cobalt-based HOIPs (Co-HOIPs) by varying the methylene chain length (n) of n = 1, 2, 3, and 4, for the first time. The Co-HOIP crystal structure with a single carbon chain displays a monoclinic arrangement with a space group of P21/c, while those with two, three, and four methylene chain lengths manifest triclinic crystal structures with a space group of P1. The optical measurements exhibit apparent odd–even effects as a function of the length of the organic ligand. The first-order phase transitions of BA2CoCl4 are distinctly observed at temperatures of 12.46 and 139.77 °C compared to the shorter EA2CoCl4 counterparts. Notably, this particular compound exhibits the highest magnetic saturation and coercive fields with Ms = 0.160 emu/g and Hc = 19.416 T, respectively. Furthermore, BA2CoCl4 demonstrates superior dielectric properties, as evidenced by the shortest diameter of the equivalent circuit in EIS. These findings underscore the potential of BA2CoCl4 for diverse applications in magnetic and electronic devices, highlighting its promising role in advanced technological applications.