RESUMEN
Graphene has received much scientific attention as an electrode material for lithium-ion batteries because of its extraordinary physical and electrical properties. However, the lack of structural control and restacking issues have hindered its application as carbon-based anode materials for next generation lithium-ion batteries. To improve its performance, several modification approaches such as edge-functionalization and electron-donating/withdrawing substitution have been considered as promising strategies. In addition, group 7A elements have been recognized as critical elements due to their electronegativity and electron-withdrawing character, which are able to further improve the electronic and structural properties of materials. Herein, we elucidated the chemistry of nanographenes with edge-substituted group 7A elements as lithium-ion battery anodes. The halogenated nanographenes were synthesized via bottom-up organic synthesis to ensure the structural control. Our study reveals that the presence of halogens on the edge of nanographenes not only tunes the structural and electronic properties but also impacts the material stability, reactivity, and Li+ storage capability. Further systematic spectroscopic studies indicate that the charge polarization caused by halogen atoms could regulate the Li+ transport, charge transfer energy, and charge storage behavior in nanographenes. Overall, this study provides a new molecular design for nanographene anodes aiming for next-generation lithium-ion batteries.
RESUMEN
Calcium titanium oxide has emerged as a highly promising material for optoelectronic devices, with recent studies suggesting its potential for favorable thermoelectric properties. However, current experimental observations indicate a low thermoelectric performance, with a significant gap between these observations and theoretical predictions. Therefore, this study employs a combined approach of experiments and simulations to thoroughly investigate the impact of structural and directional differences on the thermoelectric properties of two-dimensional (2D) and three-dimensional (3D) metal halide perovskites. Two-dimensional (2D) and three-dimensional (3D) metal halide perovskites constitute the focus of examination in this study, where an in-depth exploration of their thermoelectric properties is conducted via a comprehensive methodology incorporating simulations and experimental analyses. The non-equilibrium molecular dynamics simulation (NEMD) was utilized to calculate the thermal conductivity of the perovskite material. Thermal conductivities along both in-plane and out-plane directions of 2D perovskite were computed. The NEMD simulation results show that the thermal conductivity of the 3D perovskite is approximately 0.443 W/mK, while the thermal conductivities of the parallel and vertical oriented 2D perovskites increase with n and range from 0.158 W/mK to 0.215 W/mK and 0.289 W/mK to 0.309 W/mK, respectively. Hence, the thermal conductivity of the 2D perovskites is noticeably lower than the 3D ones. Furthermore, the parallel oriented 2D perovskites exhibit more effective blocking of heat transfer behavior than the perpendicular oriented ones. The experimental results reveal that the Seebeck coefficient of the 2D perovskites reaches 3.79 × 102 µV/K. However, the electrical conductivity of the 2D perovskites is only 4.55 × 10-5 S/cm, which is one order of magnitude lower than that of the 3D perovskites. Consequently, the calculated thermoelectric figure of merit for the 2D perovskites is approximately 1.41 × 10-7, slightly lower than that of the 3D perovskites.
RESUMEN
Background/purpose: Oral submucosal fibrosis (OSF) is a premalignant disorder positively associated with betel nut chewing. Recent studies supported the promising benefits of histone deacetylase (HDAC) inhibitors for fibrosis treatment. Here we aim to clarify the pro-fibrogenic role of HDAC9 in regulating OSF. Materials and methods: Healthy and OSF specimens were collected to investigate the clinical significance of HDAC9. Chronic arecoline treatment process was used to induce arecoline-mediated myofibroblasts-related activation of primary buccal mucosa fibroblasts (BMFs). Functional analysis of collagen gel contraction, transwell migration, and wound-healing assays were performed to assess the change in pro-fibrogenic properties of BMFs and fibrotic BMFs (fBMFs). Lentiviral-mediated HDAC9 knockdown was used to verify the role of HDAC9 in the pro-fibrogenic process. Results: We found that arecoline significantly increased the mRNA and protein expression of HDAC9 of BMFs in a dose-dependent manner. Knockdown of HDAC9 in BMFs reversed the strengthened effects of arecoline on collagen gel contraction, cell migration, and wound-healing ability. We further demonstrated that knockdown of HDAC9 in fBMFs significantly attenuated its inherent pro-fibrogenic properties. Furthermore, we confirmed a significantly increased expression of HDAC9 mRNA in OSF compared to normal tissues, which suggested a positive correlation between the up-regulation of HDAC9 and OSF. Conclusion: We demonstrated that silencing of HDAC9 inhibited arecoline-induced activation and inherent pro-fibrogenic properties, suggesting potential therapeutics by targeting HDAC9 in the OSF treatment.
