Since its founding, the institute has also conducted research in the fields in physics, chemistry and biology. The scholarly institute is part of the University of Belgrade.
Efficient and sustainable synthesis of hydrogen peroxide (H2O2) is crucial for various industrial and environmental applications, yet conventional techniques always suffer from high energy consumption and environmental concerns. Here, we propose a strategy to boost piezocatalytic H2O2 production using an advanced Step-scheme (S-scheme) heterojunction formed between hexagonal silicon carbide (2H-SiC) and cubic silicon carbide (3C-SiC) polytypes, integrated in a nanocage architecture. Precise control of 2H/3C phase ratios has been accomplished by a low-temperature magnesiothermic reduction method, enabling the engineering of S-scheme heterojunctions within SiC nanocages with optimized interfacial properties. The resultant SiC catalysts deliver an impressive H2O2 production rate of 1323.2 μmol·g-1·h-1 in pure water, which surpasses the performance of many previously reported piezocatalysts, and is mainly attributed to the synergistic effect between heterojunctions and nanocage configuration. It is verified that the 2H-SiC phase contributes strong piezoelectric polarization, while the built-in electric field (BIEF) enabled by 2H-/3C-SiC heterojunctions facilitates effective charge separation, thus promoting efficient redox reactions. Moreover, the unique nanocage architecture optimizes the stress distribution to further enhance piezocatalytic response. This work provides a pathway for rationally designing high-performance piezocatalysts toward highly efficient and sustainable H2O2 production.
Wooden waste railroad ties preserved with coal tar creosote oil represent a specific source of polluting substances. The aim of this study was to investigate and compare extraction capacity due to solvent extraction of fifteen frequently used organic solvents for the purpose of decontamination treatment of waste wooden railroad ties, while recovering wood for reuse. Pure organic solvents, ethanol 96%, propan-2-ol, deionized water, dichloromethane, acetone, n-hexane, mixture n-hexane/acetone (V/V = 1/1), cyclohexane, methanol, N,N-dimethyl formamide, toluene, ethyl acetate, acetonitrile, amyl acetate, medical gasoline, n-pentane and n-butyl acetate were for leaching pollutants from waste railroad ties. The highest extraction capacity was achieved using dichloromethane, where 7.50 to 7.89 wt.% of total sixteen polycyclic aromatic hydrocarbons were extracted from waste railroad tie chips. The most promising solvents for the treatment exhibited extraction efficiency which decreases in a series dichloromethane > n-hexane/acetone > acetone > methanol > ethanol 96% > propan-2-ol > cyclohexane > toluene > n-hexane. Solvent extraction represents a novel approach for treatment of wooden waste railroad ties. The experiments are based on the search for a management process for the treatment of wood waste railroad ties that is simple, low energy consumption, efficient and could potentially be applied for large scale.
A practical and environmentally friendly microwave-assisted method was developed for synthesizing nano-structured monoclinic scheelite-type bismuth vanadate (ms-BiVO4) photocatalyst. This work, for the first time, highlights a favorable relationship between crystal size, microwave irradiation efficiency, and the time needed for its formation in water as the only solvent. Energetic and uniform microwave heating at 170 degrees C produces a light yellow powder after 10 min of irradiation. Uniformly dispersed, spherical nanocrystals with a size of approximately 20 nm and high crystallinity were determined using TEM and XRD, respectively. The band gap energy of ms-BiVO4 is estimated to be about 2.55 eV. The present functional groups were confirmed through FTIR analysis. The photocatalytic efficiency was assessed through degradation studies using Rhodamine B (RhB) dye under simulated sunlight irradiation, demonstrating an impressive degradation rate after 20 min of illumination at a pH 2 environment. The present study further elucidates the photocatalytic performance of ms-BiVO4, assessing factors influencing efficiency, including catalyst dosage, initial dye concentration, solution pH, and reaction time. Furthermore, the electrochemical performance of ms-BiVO4 as an electrode material was investigated, revealing that ms-BiVO4 is suitable for electrochemical sensing in complex matrices and techniques that demand high sensitivity and reproducibility.
Attaining and keeping accuracy levels in deployed low cost air quality multisensory systems (LCAQMS) is a challenging and costly task. Current methodologies, in particular, rely on repeated calibrations by colocation with references grade analyzers or, whenever possible, remote imputations. These are respectively affected by logistic costs and deployment delays or high quality remote data availability dependance. This work introduces a novel methodological approach which aims to obtain a continuous, in-place, innetwork recalibration procedure able to attain sufficiently accurate measurements from day zero in high density deployment scenarios while greatly reducing the total costs of ownership and operation. Based on the Federated Learning concept (FL), a limited subset of devices are collocated with reference stations obtaining data capable to produce local calibration models which contribute by harmonization to the development and deployment of a universal calibration model which can be exploited by all the deployed devices, notwithstanding their number. Preliminary, while encouraging, results, based on publicly available dataset exploitation, are here presented.
Abstract When applying attosecond pulse train (APT) (kicks) to the Aubry–André (AA) model, atto-localization appears. The velocity gauge is implicated. Atto-localization is proven considering kick also in the length gauge. This is a new type of localization and here its concrete analysis is presented. First, it is given how APT can be applied to this model. Then, for atto-localization, it is examined in detail what localization length is and how it changes with kicks. In particular, it has been established that after enough kicks the main feature of the AA model reflects across the localization length. This is a surprising result. It has also been verified on density of states. Further, the extended AA model is considered. Here, a concrete benefit of atto-localization has been shown.
