Chemistry of Inorganic Materials最新文献

Furfuryl alcohol (FOL) is a biomass derivative used in polymer and fine chemical industries. Hydrogenation of FOL was reported to give tetrahydrofurfuryl alcohol (THFA), while its hydrogenolysis gave 1,2-pentanediol (1,2-PeD) and 1,5-pentanediol (1,5-PeD) in pressurized hydrogen by platinum group metals (e.g., Ru, Pd, and Pt). Herein, cobalt tungstate (CoWO₄) catalyzed selective hydrogenation or hydrogenolysis of FOL to give THFA or 1,2-PeD in the absence of pressurized hydrogen. Crystalline CoWO₄ was synthesized hydrothermally at a relatively lower temperature (<160 ​°C) and shorter time (<10 ​h) compared to reported procedures (180–200 ​°C, 15–24 ​h). Lower hydrothermal temperature (<150 ​°C) yields low-crystalline CoWO₄. Catalytic differences of CoWO₄ in crystalline and low-crystalline phases were observed in hydrogenolysis of FOL in alcohols. We found that 1,2-PeD of 67% was selectively achieved in 2-propanol at 160 ​°C for 7 ​h by low-crystalline CoWO₄ (5 ​mol%), while the same reaction in ethanol gave 54% THFA. The reaction was proposed to be a pseudo first-order towards FOL with the experimental energy barrier of 107 ​kJ/mol and turnover frequency (TOF) up to 3.6 ​h⁻¹.

Magnetic nanoparticles (MNPs) owing to its broad application spectrum are gaining popularity in recent years. The current review article offers a one-stop-reference for young scientists as it encompasses the literature reports on method of synthesis and functionalization of MNPs based systems and their potential applications spectrum in diverse fields. This review summarizes in details about different methods reported in literature for the synthesis of MNPs, need of functionalization of MNPs, immobilization of active species onto the surface of functionalized MNPs and their applications in carrying out biologically important organic transformation. Applications of MNPs are not only restricted to the field of catalysis but also showed potential applications in different sectors. Over the last few decades, there has been increasing global concern over public health issues due to contamination of water bodies with harmful dyes and toxic metals. Monitoring and subsequent removal of these harmful dyes and toxic metals from the contaminated water is one of the major environmental remediation interests today. In this context, MNPs based absorbents have shown exuberant potential to remove deleterious pollutants from water bodies owing to their high removal efficiency, low cost, faster kinetics, easy accessibility and design flexibility. Besides, MNPs have also proved their potential in the field of enzyme and pharmaceutical industries. MNPs being the major class of nanoscale materials are revolutionizing the current clinical diagnostic and therapeutic techniques and are currently employed as next generation drug carriers. Furthermore, Magnetic NP-Based Biosensors was also employed for detection of the presence of SARS-CoV-2, a ribonucleic acid (RNA) virus responsible for nearly 6.1 million deaths occurred due to COVID-19 pandemic. MNPs based system also showed their potential in fuel industry as it is used in the production of biodiesel which emerges as a promising alternative to fossil fuel derived energy sources because it is eco-friendly, clean and biodegradable in nature. In short, we have provided in-depth details about the MNPs, their synthesis, functionalization and their applications in diverse fields.

Due to the toxicity and the complex fabrication process lead-based perovskite solar cells are difficult to fabricate commercially though the power conversion efficiency has reached 25.2 ​%. In the current scenario, lead free perovskite solar cell devices are gaining interest among the researchers and the bilayer structure is showing significant improvement in the efficiency. In this work, with the help of SCAPS 1D, a lead free single-layer perovskite (CH₃NH₃SnBr₃) solar cell and a bilayer structure (CH₃NH₃SnBr₃/CIGS) have been investigated to compare the photovoltaic performance by using PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) and SnTe as an electron transport layer (ETL) and hole transport layer (HTL) respectively. Different device parameters i.e. thickness, defect density, doping concentration and series-shunt resistance of the device was optimized to obtain the best performance. In the case of a single absorber layer, power conversion efficiency (PCE), open circuit voltage ($V_{\text{oc}})$, fill factor (FF) and the short circuit current density $\left(J_{\text{sc}}\right)$ were achieved 20.58 ​%, 0.931 ​V, 64.95 ​% and 34.03 ${\text{mA}.\text{cm}}^{-2}$ respectively. However, it is observed that bilayer structure (FTO/PCBM/CH₃NH₃SnBr₃/CIGS/ZnTe/SnTe/Au) obtains 22.68 ​% of PCE, 0.916 ​V of $V_{\text{oc}}$, 71.46 ​% of FF and 34.66 ${\text{mA}.\text{cm}}^{-2}$ of $J_{\text{sc}}$. This study suggests that a proper bilayer structure is beneficial to improve the device performance in terms of J_sc and FF by increasing the carrier generation and reducing the back surface field recombination.

The wide utilization of perovskite material as an absorber layer in solar cells necessitates favorable alignment with the perovskite's conduction band, governed by FTO/TiO₂ (SnO₂). Instead of an ideal electric-selective contact, further improvement of the hole-selective contact is crucial to enhance hole extraction and minimize carrier recombination at the interface between perovskite and spiro-OMeTAD. In this study, we employed series of polar organic molecules [2,4-dimethyl-6,8-bis(4-(methylthio)phenyl)pyrrolo [1,2-a]pyrimidine-7-carbonitrile (PCNS), 2,4-dimethyl-6,8-diphenylpyrrolo [1,2-a]pyrimidine-7-carbonitrile (PCN), and 2,4-dimethyl-6-8-(pyren-1-yl)pyrrolo [1,2-a]pyrimidine-7-carbonitrole (PCNP)] with cyano groups as the interfacial passivate layer to facilitate energy band matching between the perovskite and the hole transport layer as confirmed by the energy band bending at the perovskite surface. Consequently, we achieved effective charge carrier extraction and suitable bandgap alignment. A detailed comparative analysis of the photophysical and electrical properties among the three molecules elucidated the origin of higher open circuit voltage (1.18 ​V) and improved fill factor (83.15 %) in the solar cell device based on PCN molecule (24.22 %).

This study analyzes the structural characteristics of mesoporous carbon (CMK-3) and how they affect the specific capacity of Li-ion batteries (LIBs). To achieve this, CMK-3 is synthesized with and without the addition of oxalic acid as a catalyst to polymerize furfuryl alcohol (carbon precursor) in the template-assisted synthesis process using mesoporous silica. CMK-3 (without oxalic acid) and CMK-3_O (with oxalic acid) exhibit rod-like particles with cylindrical pores, showing high specific surface area (SSA) of 998 and 1067 ​m² ​g⁻¹ and oxygen-to-carbon ratios of 0.23 and 0.43, respectively. At 178 ​mA ​g⁻¹, the electrodes demonstrate specific capacities of 993 ​mA ​h ​g⁻¹ (CMK-3) and 520 ​mA ​h ​g⁻¹ (CMK-3_O). According to the cyclic voltammetry technique, the non-diffusion-controlled process (approximately 55 ​%) significantly contributes to the total charge storage in CMK-3. Although electrodes (CMK-3 and CMK-3_O) have similar SSA, this study highlights the significance of the disordered and defective structure in achieving a higher specific capacity from the same material without any changes in morphology, particle size, or synthesis route. Consequently, this work emphasizes the necessity of considering the structural properties of porous carbon electrodes when developing high-performance batteries for electric vehicles, where specific capacity and cyclic stability are crucial.

The interactions of the fine decomposed peat (FDP) of Arroio Silva, SC, Brazil, with the Al(III) ion were studied. The infrared (IR) spectrum confirmed the presence of the characteristic functional groups of peat. Kinetic studies revealed that, with a high correlation coefficient, the pseudo-second-order model shows a good agreement between the experimental and calculated q_e values. This indicates that in the adsorption of Al(III) ion the determining step is a chemical adsorption, involving chelation. The process is described by the Langmuir adsorption model, which is limited to the formation of a monolayer of metallic ions. According to this model, the maximum adsorption capacities at pH 1.0, 2.5 and 4.0 were, respectively, 5.42, 5.89 and 6.09 ​mg of aluminum per gram of peat. The suggested adsorption mechanism involves the complexation of the Al(III) ion with the oxygenated groups present in the peat. The electron microscopy analysis showed a rough and porous surface and the determination of the point of zero charge (PZC) indicates that the interactions of the Al(III) ion with the peat are much stronger than simple electrostatic interactions. The molar amounts of the most important functional groups present and the equilibrium constants of Al(III) ion interactions with these groups were calculated and the distribution curves were obtained. At pH values up to pH ​= ​4.4, the Al(III) ion is preferably coordinated with the phthalic group. At higher pH values several interactions occur, for instance, between: a monohydroxide and the phthalic group, Al(OH)(Pht); a dihydroxide, a phthalic and a catechol group, which predominates at pH values of 4.5 to 8.2, [Al(OH)₂(Pht)(Cat)]^3-; and a monohydroxide bisphtalic, [Al(OH)(Pht)₂]^2-, a dihydroxide, a catechol and a salicylate group, [Al(OH)₂(Cat)(Sal)]^3-, which competes with the aluminate ion, Al(OH)₄^- . The linear relationship of Stern-Volmer suppression of the fluorescence of the aromatic groups present in the peat with the Al(III) ion confirms the equilibrium results.

A new avenue for modifying the physical and chemical characteristics of the semiconducting polymers is opened by the incorporation of conducting polymers coated with inorganic nanoparticles into the semiconducting host polymers. For the manufacture of polyaniline (PANI) composites containing copper sulfide (PANI@CuS) and subsequent introduction to polyvinyl alcohol (PVA), an in-suite polymerization process was used. In the current study, PVA/PANI@CuS hybrid nanocomposites (NCs) were prepared using an environmentally friendly solution casting technique with PANI@CuS concentrations of 0, 1, 2, 3 and 4 ​wt%. To assess their morphological, electrical, optical, and surface characteristics, the prepared polymer hybrid nanocomposites were put through a variety of analytical techniques. The molecular connection between CuS, PANI, and PVA is visible thanks to X-ray diffraction and FT-IR investigations. The refractive index rises from 1.40 to 1.73 while the band gap in the UV–Visible decreases from 6.17 to 3.43, providing information on the optical characteristics. Additionally, photoluminescence spectra exhibit a 150 ​nm Stokes shift towards higher wavelengths, opening up additional opportunities for photovoltaic applications. The electrical characteristics were examined using a scanning electron microscope (SEM), and it was discovered that the conduction mechanism adheres to the Poole-Frenkel effect. The obtained findings demonstrate that the addition of PANI@CuS significantly improves the host polymer matrix's opto-electronic characteristics.