UV Vis Absorption Spectra Research Articles

Synthesis and characterization of new naphthalene diimides (NDIs) for application in electronic devices

This paper describes the synthesis of new naphthalene diimide (NDI) derivatives obtained in good yields from the reaction between 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) and different p-alkoxy-substituted anilines. The photophysical properties of the NDIs were investigated in solution and the solid state. UV–visible absorption spectra in 1,4-dioxane, dichloromethane, and acetonitrile showed absorption maxima at approximately 375 nm, related to symmetry and spin allowed 1π-π* electronic transitions. These compounds did not exhibit fluorescence emission in the studied solvents. Electrochemical studies have indicated that the presence of different alkyl chains significantly affects the capacity of NDIs when used as organic cathodes in Al-graphite batteries due to variations in their ability to intercalate tetrachloroaluminate. The organic cathodes incorporating NDIs with varying alkyl chain lengths exhibited distinct capacities: 123.5 mA h g⁻1 for 3a, 101.6 mA h g⁻1 for 3b, and 157.3 mA h g⁻1 for 3c, with a capacity retention of approximately 54 % after 15 charge‒discharge cycles. These findings highlight the crucial role of alkyl chain modification in optimizing the electrochemical performance of organic cathodes.

Novel White Phosphor Bi3+ co-doped SrCeO3: 2 wt% Sm3+ Synthesized via Fuel Excess Gel Combustion Synthesis for wLED Applications.

Co-doping strategy is done if the emission from the activator is relatively low with existing excitation energy. Thus, to enrich the emission from an activator, the sensitizer like Bi3+ is co-doped onto the host and this intermediator transfers its emission energy to the activator. Prior to the study, no investigations had been conducted, marking the foundational exploration of the sensitizer effect within the rare earth-doped SrCeO3 matrix aimed at enhancing luminescence properties. The current study focuses on the innovation of single-phase robust white phosphors, SrCeO3: 2wt% Sm3+: xBi3+ (x = 0 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%) to coat near UV LED chips for high CRI wLED applications. The novel perovskites were synthesized using a low-temperature fuel excess gel combustion method, utilizing citric acid as the fuel and ammonium nitrate as an extra oxidizer. Upon co-doping SrCeO3: 2wt% Sm3+ with bismuth, the impact of changing sensitizer concentration on both the development of crystalline phases, morphology, elemental composition, band gap energy, and the luminescent properties of ceramic powders were explored through X-ray diffraction, FE-SEM, Energy dispersive spectra, UV-visible absorption spectra, and photoluminescence characterization methods. The experimental results revealed the orthorhombic single-phase formation of SrCeO3: 2wt% Sm3+: xBi3+perovskites yielding high crystallinity and luminescence maximum at critical sensitizer concentration 1 wt% Bi3+. Also, the bright white light emission of all the perovskites was confirmed using the CIE color diagram. Thus, nano-perovskite SrCe0.97Sm0.02O3: 1wt% Bi3+ acts as an inevitable direct phosphor coating the near UV chip in LEDs, which can be a great revolution in energy savings applications.

Ti3+ self-doped TiO2 nanoparticles immobilized on self-pillared pentasil zeolite nanosheets: An efficient visible-light-driven degradation photocatalyst

Ti3+ defective TiO2 nanoparticles (TiO2-NPs) were synthesized through slow hydrolyzation of tetrabutyl titanate and low-temperature annealing, followed by loading on self-pillared pentasil (SPP) zeolite nanosheets to construct a TiO2/zeolite hybrid composite by solid-state dispersion. The obtained TiO2-NPs/SPP composite exhibited a distinct red-shift in the UV–vis absorption spectrum and a significantly reduced band gap due to the introduced Ti3+ defects and the consequent oxygen vacancies (VO), leading to an enhanced visible-light responsivity. The diverse porosity and house-of-cards nanosheet morphology of the SPP support not only promoted the efficient loading and stable immobilization of TiO2-NPs nanoparicles through micropore migration and surface adhesion but also endowed the adsorbability to the TiO2-NPs/SPP composite. The adsorptive photodegradation of methylene blue (MB) was used to evaluated the photocatalytic performance of TiO2-NPs/SPP, and a 95.6 % degradation rate of MB was observed after 3 h illumination with visible-light. The adsorptive effect strongly promoted the accessibility of MB molecules to the active TiO2 species, leading to a remarkable enhancement in degradation efficiency. Moreover, a superior recyclability embodied in the retention of 96.4 % photocatalytic activity after three regeneration cycles indicated the TiO2-NPs/SPP composite to be practical for water pollutant degradation.

The interaction between resveratrol and catalase was studied by multispectral method and molecular docking simulation

In this research, we delved into the interaction mechanism between Resveratrol (RES) and Catalase (CAT) utilizing a suite of advanced analytical techniques, including multispectral analysis and molecular docking simulation. A comprehensive assessment of their binding characteristics, modalities, distances, and the subsequent impact on CAT's secondary structure was conducted through fluorescence spectroscopy, ultraviolet spectroscopy, circular dichroism, three-dimensional fluorescence spectroscopy, synchronous fluorescence spectroscopy, and molecular docking simulation. By employing the Stern-Volmer equation to determine KSV and Kq values, Our findings indicate that the RES-CAT interaction results in static fluorescence quenching, By conducting experiments, the binding constant KA and the number of binding sites n for CAT and RES were determined, with the number of binding sites n being close to 1, indicating the presence of a specific binding site between CAT and RES. Parameters at 298 K. The negative values of ΔH and ΔS suggest that van der Waals forces and hydrogen bonding are predominant in mediating the interaction between CAT and RES. The negativity of ΔG indicates the spontaneity of the reaction. The Fӧrster resonance energy transfer theory calculation revealed a binding distance of 4.917 nm, substantiating the occurrence of non-radiative energy transfer between RES and CAT. Furthermore, the UV-VIS absorption spectrum, synchronous fluorescence spectrum, three-dimensional fluorescence spectrum, and circular dichroism analyses collectively demonstrated that RES induces alterations in CAT's secondary structure, augmenting the polarity around tryptophan (Trp) residues, reducing hydrophobic interactions, and bolstering hydrophilicity. This work offers novel insights into the antioxidant mechanisms of resveratrol within biological systems and holds significant theoretical and practical implications for the medical application and development of resveratrol.

Utilizing the 2nd harmonic Nd: YAG laser ablation in liquid for the production of copper oxide quantum dots: Influence of laser fluence and ablation duration

One environmentally friendly technique for creating colloids of nanoparticles is pulsed laser ablation in liquid, which stands out for its ability to create nanoparticles free of contamination without the use of hazardous chemicals. In the present work, A Q-Switched Nanosecond Nd: YAG laser was utilized to precisely produce colloidal copper oxide nanoparticles (CuONPs) through the laser ablation of a copper target immersed in distilled water. The impact of the laser fluence and laser ablation time on the size, morphology, and concentration of the generated CuONPs was investigated experimentally. The UV–visible absorption spectra of CuONPs display surface plasmonic resonance peaks in the UV region, which are attributed to interband transitions. The energy band gaps of the colloidal CuONPs were determined using UV–visible spectroscopy, and they ranged between 3.45 and 3.72 eV at various ablation times and laser fluences. The TEM micrographs were used to assess the size and morphology of the CuONPs, while the concentration and elemental composition were determined using ICP and EDXA spectroscopy. The TEM images of the CuONPs indicate a spherical shape at various laser ablation times and laser fluences. The average size of the CuONPs decreased to the quantum size range. The experimental results show that increasing laser fluence from 28.6 to 51.5 × 103 J/cm2 while keeping laser ablation time fixed for 30 min resulted in a reduction in the average size of the nanoparticles from 8.5 to 4.6 nm, respectively. Moreover, increasing laser ablation time from 10 to 50 min at a constant incident laser fluence of 34.3 × 103 J/cm2 decreased the average size of the CuONPs from 6.8 to 4.3 nm, respectively. The concentration of the synthesized CuONPs increased as laser fluence and laser ablation time increased.

Structural, optical, and morphological properties of PVC-BaTiO3 nanocomposite films

This work aims to fabricate barium titanate (BaTiO3) nanoparticles and study the effect of adding different contents of BaTiO3 nanoparticles on the structural, optical, and electrical properties of PVC polymer matrices. The PVC/BaTiO3 nanocomposite films were characterized by X-ray diffraction, FT-IR spectroscopy, and SEM. In addition, dielectric properties were studied within the frequency range of 0.1 KHz–6 MHZ. The XRD analysis reveals an amorphous nature of pure PVC with two characteristic peaks at 2θ = 17.09° and 2θ = 23.25°, and it reveals that BaTiO3 has sharp and narrow peaks. In PVC/BaTiO3 nanocomposite films, all XRD peaks of BaTiO3 appeared in all the samples with an increase in the average particle size from ∼46 nm to 55 nm. There is no shift of IR position in PVC bands, but the decreased intensity of some bands suggests complexation between PVC and BaTiO3. The UV–visible absorption spectrum of pure PVC has a band at λ = 278 nm. This band was shifted to 252 nm after adding BaTiO3 content. UV–visible transmission spectra demonstrate a decrease in the transmittance as an increase of BaTiO3 content from 89.23 % for pure PVC to 5.23 % for 0.1 wt% of BaTiO3. The values of the optical bandgap decrease with increasing BaTiO3 contents due to defect formation in PVC matrices. The optical parameters of the prepared nanocomposite films were also enhanced. The AC conductivity shows an increase with both frequency and BaTiO3 concentration, leading to enhanced movement of charge carriers and relaxation of interface polarization.

Computational investigation for electronic, structural, linear/nonlinear optical responses for newly designed organometallic quantum dots

AbstractThe interaction of metallic ($$M^{ + 3}$$ M + 3 )-cations ($$M = {\text{Al}},{\text{Cu}},{\text{Zn}},{\text{In}},{\text{Ga}},{\text{Ge}},{\text{Sb}},{\text{Sn}}$$ M = Al , Cu , Zn , In , Ga , Ge , Sb , Sn ) with an active organic linker result in the formation of organometallic quantum dots (OMQDs). The B3LYP and WB97X interfaces via 6-311G++(d,p) route are used to test the stability, electrical, optical, and nonlinear-optics (NLO) properties. OMQD UV–Vis absorption spectra are computed. Some OMQD have singlet spin states, while others have doublet spin states. Cation mobility and the organic linker nature have a significant impact on both optical and NLO properties. For electron rush via the conduction domain, doublet spins provide more advanced turnabilities than singlets. For singlet-spin Cu-3HPHP QDs, an anomalous NLO response is endorsed. Both Zn-3HPHP and Sn-3HPHP QDs are recognized as the finest contenders. Zn-3HPHP and Sn-3HPHP appear to be the next covenant for highly efficient optoelectronics and avalanche photodetectors.

Surprising Effects of Al2O3 Coating on Tribocatalytic Degradation of Organic Dyes by CdS Nanoparticles

With a band gap of 2.4 eV, CdS has been extensively explored for photocatalytic applications under visible light irradiation. In this study, CdS nanoparticles have been investigated for the tribocatalytic degradation of concentrated Rhodamine B (RhB) and methyl orange (MO) solutions. For CdS nanoparticles in a glass beaker, 78.9% of 50 mg/L RhB and 69.8% of 20 mg/L MO solutions were degraded after 8 h and 24 h of magnetic stirring using Teflon magnetic rotary disks, respectively. While for CdS nanoparticles in a beaker with Al2O3 coated on its bottom, 99.8% of the RhB solution was degraded after 8 h of magnetic stirring and 95.6% of the MO solution was degraded after 12 h of magnetic stirring. Moreover, another contrast was observed between the two beaker bottoms—a new peak at 250 nm in UV–visible absorption spectra was only observed for the MO degradation by CdS in the as-received glass beaker, which indicates that MO molecules were only broken into smaller organic molecules in that case. These findings are meaningful for expanding the catalytic applications of CdS and for achieving a better understanding of tribocatalysis as well.

Efficient degradation of emerging pollutant-malachite green in water by pulsed discharge plasma on water surface in cooperation with Fe2+/PMS

The effective and rapid treatment of emerging pollutants in water is an essential solution to the pollution of water environment. The emerging pollutant-malachite green (MG) wastewater was treated using pulsed discharge plasma on water surface system (WSP) combining Fe2+/PMS. Compared with WSP alone, the addition of 125 μM Fe2+ and 0.5 mM peroxymonosulfate (PMS) in WSP could enhance the degradation efficiency and energy efficiency of MG by 32.8% and 9.7% respectively, with the synergistic factor of up to 2.056. UV–Vis absorption spectra and mineralization further demonstrated the synergistic effect. When the peak voltage and air flow rate were 22 kV and 0.7 L/min, the degradation efficiency and kinetic constant of MG could reach 97.9% and 0.259 min−1, respectively. MG degradation with high conductivity (1000 μS/cm) by WSP + Fe2+/PMS not only exhibited the better purification effect, but also could maintain the faster reaction rate. The active species involved in the degradation of MG in WSP + Fe2+/PMS system were mainly ·OH, SO4·−, O2·− and e*−. Furthermore, H2O2 and O3 also have a certain oxidizing effect on MG. Cl−, SO42−, HCO3− and humic acid (HA) could inhibit MG degradation to some extent, but still removed more than 80% of MG in water. The WSP + Fe2+/PMS reaction system was suitable for the treatment of other emerging pollutants in water. The results of LC-MS analysis revealed that the N-demethylation reaction and decomposition of conjugated structure were the important pathways for MG degradation. The H2O2 and acidic liquid environment provided by WSP laid the foundation for the formation of Fenton, and the introduced Fe2+ could fully undergo the Fenton and activation reaction with H2O2 and a small amount of PMS in the liquid phase, which enhanced the generation of active species, especially ·OH.

Colorimetric sensors for discriminatory detection of arsenite ions: Application in milk, honey and water samples and molecular logic gates

Millions of people are exposed to dangerous arsenic levels in drinking water, highlighting the urgent need for affordable, continuous on-site arsenic monitoring methods. It is crucial to specifically detect arsenite among inorganic arsenic anions because it is more poisonous than arsenate. Addressing these concerns, the present study developed 5-(4-nitrophenyl)-2-furaldehyde based two colorimetric chemosensors, N5R3 and N5R4, with different signaling groups for the selective detection of arsenite anions over arsenate in DMSO/H2O (6:4, v/v). The red-shift in the UV–Vis absorption spectra supported the distinct color changes of sensors N5R3 and N5R4 displayed upon binding with arsenite. Sensors demonstrated stability over a pH range of 6 to 12 and exhibited stability over a considerable time period. Among the chemosensors, N5R3 exhibited the lowest detection limit of 7.41 ppb with a high binding constant of 2.9976 × 106 M−1 for arsenite. The 1:1 binding interactions between the chemosensors and arsenite were confirmed using B-H plot and Job’s plot analysis. The intramolecular charge transfer (ICT) mechanism for detecting arsenite was proposed through UV and 1H NMR titrations, electrochemical studies, mass spectral analysis and DFT calculations. The interactions between the sensor and arsenite anions were further analyzed using global reactivity parameters (GRPs). Practical applications were demonstrated through the utilization of test strips and molecular logic gates. Both chemosensors efficiently recognized arsenite in real water, honey, and milk samples.

Color-Stable Formulations for 3D-Photoprintable Dental Materials.

Color stability is crucial for dental materials to ensure they perfectly match a patient's tooth color. This is particularly challenging in photoresist-based additive manufacturing. Although some studies have addressed this issue, the exact causes of discoloration and ways to minimize it remain unclear. In this study, the intrinsic causes of discoloration in materials intended for 3D printing are investigated by examining thin-film samples (1200 µm) of various compositions, which are stored under different conditions. The samples are evaluated by measuring the UV-Vis absorption spectra at regular intervals to monitor changes. The findings reveal that both the composition of the formulations and the storage conditions significantly influence the discoloration behavior. Furthermore, methods have been developed to reduce or completely prevent discoloration. The use of photoinitiators with sterically demanding benzoyl moieties, as well as the addition of stabilizers, effectively decreases the intensity of emerging discoloration. Furthermore, incorporating the oxidizing agent cumene hydroperoxide (CHP) results in materials that maintain color stability.

Construction of Ternary Ce Metal-Organic Framework/Bi/BiOCl Heterojunction towards Optimized Photocatalytic Performance.

Photocatalysis is the most promising green approach to solve antibiotic pollution in water, but the actual treatment effect is limited by photocatalytic activity. Herein, Bi and BiOCl were loaded onto the surface of Ce-MOF (metal-organic framework) using an electrostatic adsorption method, and a special ternary heterojunction of Ce/Bi/BiOCl was successfully prepared as a photocatalyst for the degradation of tetracycline (TC). FTIR demonstrated that the obtained photocatalyst contains functional groups such as -COOH belonging to Ce-MOF and characteristic crystal planes of Bi and BiOCl, indicating the successful construction of a ternary photocatalyst. The results of UV-vis absorption spectra confirm that the band gap of Ce/Bi/BiOCl heterojunction is reduced from 3.35 eV to 2.7 eV, resulting in an enhanced light absorption capability in the visible light region. The special ternary heterojunction constructed by Ce-MOF, Bi, and BiOCl could achieve a narrow band gap and reasonable band structure, thereby enhancing the separation of photogenerated charges. Consequently, the photocatalytic performance of the Ce/Bi/BiOCl ternary heterojunction was significantly enhanced compared to Ce-MOF, Bi, and BiOCl. Therefore, Ce/Bi/BiOCl can achieve a photocatalytic degradation rate of 97.7% within 20 min, which is much better than Bi (14.8%) and BiOCl (67.9%). This work successfully constructed MOF-based ternary photocatalysts and revealed the relationship between ternary heterojunctions and photocatalytic activity. This provides inspiration for constructing other heterogeneous catalysts for use in the field of photocatalysis.

A new method for the rapid identification of external water types in rainwater pipeline networks using UV–Vis absorption spectroscopy

Ultraviolet–visible (UV–Vis) absorption spectroscopy, due to its high sensitivity and capability for real-time online monitoring, is one of the most promising tools for the rapid identification of external water in rainwater pipe networks. However, difficulties in obtaining actual samples lead to insufficient real samples, and the complex composition of wastewater can affect the accurate traceability analysis of external water in rainwater pipe networks. In this study, a new method for identifying external water in rainwater pipe networks with a small number of samples is proposed. In this method, the Generative Adversarial Network (GAN) algorithm was initially used to generate spectral data from the absorption spectra of water samples; subsequently, the multiplicative scatter correction (MSC) algorithm was applied to process the UV–Vis absorption spectra of different types of water samples; following this, the Variational Mode Decomposition (VMD) algorithm was employed to decompose and recombine the spectra after MSC; and finally, the long short-term memory (LSTM) algorithm was used to establish the identification model between the recombined spectra and the water source types, and to determine the optimal number of decomposed spectra K. The research results show that when the number of decomposed spectra K is 5, the identification accuracy for different sources of domestic sewage, surface water, and industrial wastewater is the highest, with an overall accuracy of 98.81%. Additionally, the performance of this method was validated by mixed water samples (combinations of rainwater and domestic sewage, rainwater and surface water, and rainwater and industrial wastewater). The results indicate that the accuracy of the proposed method in identifying the source of external water in rainwater reaches 98.99%, with detection time within 10 s. Therefore, the proposed method can become a potential approach for rapid identification and traceability analysis of external water in rainwater pipe networks.

Two three-dimensional coordination polymers as fluorescence probes for the detection of nitrobenzene, tetracycline, fluazinam and their application in green pepper

Two coordination polymers (CPs), [Zn5(L)2(phen)5](1) and [Cd2(HL)(2,2-bpy)(H2O)3](2), were synthesized by using 2′,3,3′,5,5′-Diphenyl ether pentacarboxylic acid (H5L), phenanthroline (phen), and 2,2′-bipyridine (2,2′-bpy) under hydrothermal conditions. The L5- ligand adopts the μ6-к2: к2: к1: к1: к1: к1 mode in 1 and the μ5-к2: к2: к2: к2: к1 mode in 2. Sensing experiments show that 1 and 2 are fluorescence probes with high sensitivity and rapid detection of nitro explosives, antibiotics, and pesticides. In order to verify the ability of 2 to detect FLU in actual samples, we performed a spiked recovery experiment in green pepper water. The spiked recoveries were 97.77–101.18 %. Interestingly, because H5L is not completely deprotonated in 2, there is abundant hydrogen bonding, which makes the fluorescence quenching rate higher and the detection limit lower. The possible fluorescence quenching mechanism of 1 and 2 can be explained by their UV–VIS absorption spectra and orbital energy levels.

Synthesis and characterization of novel double perovskite K2AgBiBr6

Over the past few years, Lead-free halide double perovskites have attracted a tremendous attention such that it is demonstrated by the power conversion efficiency's sharp increase of over 25 %. It has also stimulated a widespread application of halide metal perovskites in other fields, such as light-emitting diodes, field-effect transistors, detectors, and lasers. Double perovskites have been put forth as an alternative to hybrid lead halide perovskites in the last decade because of their efficiency in doing away with the existing toxicity and instability. It is probably the first attempt, to date, that lead-free halide double perovskite K2AgBiBr6 has been made with a cheap, easy-to-use solution-state reaction method. To determine their structure, single crystal X-ray diffraction and PXRD analysis have been employed. The synthesized K2AgBiBr6 adopts the cubic structure with Fm‾3m symmetry and lattice parameters of a = 6.606 (9) Å at room temperature, according to the diffraction result. Energy dispersive X-ray spectroscopy (EDX), elemental mapping, and scanning electron microscopy (SEM) have all been employed to analyze the morphology and elemental composition. Elements including K, Bi, Ag, and Br have been confirmed to be present in the synthesized sample by the EDX technique. For K2AgBiBr6, the 2.859 eV (indirect) and 3.076 eV (direct) bandgaps have been estimated by employing the UV–Vis absorption spectra. Furthermore, the K2AgBiBr6 double perovskite nanocrystal's thermogravimetric analysis/differential thermal and differential scanning analysis (TG/DTA and DSC) curves at 20–800 °C have been measured. An analysis has been conducted on the mechanism of thermal decomposition of synthesized double perovskite. This work demonstrates great promise for future band gap engineering-based photovoltaic and other optoelectronic applications, and it offers a novel path to obtaining premium K2AgBiBr6 double perovskite.

Structural, optical and magnetic properties of chemically grown copper oxide nanoparticles: An insight into anticancer activities

Self-assembling nanorods like copper oxide (CuO) nanoparticles (NPs) have been successfully synthesized using two different copper cationic precursors to investigate their structural, optical, and magnetic properties. These NPs are employed in anticancer applications. Both the CuO-NPs have been tested for their toxicity on human cells. The XRD patterns confirm the formation of monoclinic crystal structures for both the systems. The FESEM microstructural surface morphology shows high agglomeration and a typical elemental composition is evaluated from EDAX analysis. The HRTEM analysis reveals high crystalline CuO nanorods with diameters in the range of 60 ∼ 94 nm and 09∼ 22 nm for two different nanoparticles named CuO-NPs1 and CuO-NPs2, respectively. The optical band gap of CuO-NPs has been calculated from UV–visible absorption spectra and is found to be 2.18 eV and 2.55 eV for CuO-NPs1 and CuO-NPs2, respectively. FTIR analysis provides insights into the chemical compositions of both the CuO-NPs. Magnetization study using vibrating sample magnetometer (VSM) indicates antiferromagnetic-like properties associated with weak ferromagnetic behaviour. Cytotoxicity tests on MCF-7 cell lines show that CuO-NPs2 exhibit more pronounced effect with IC50 of 22.95 μg/mL. The toxicity of both the CuO-NPs are also assessed using human lymphocytes, suggesting that CuO-NPs could be promoted as anticancer agents while remaining non-toxic to biological systems.

Nitrated benzothiadiazole-based D-A electrochromic polymers with tunable spectral properties

Nitrated benzothiadiazole (BT) is the promising acceptor units in constructing D-A-D electrochromic polymers, but its researches in the electrochromic field was very limited so far. In this work, four kinds of nitrated polymer precursors (Th-NO2-BT, EDOT-NO2-BT, Th-2NO2-BT, and EDOT-2NO2-BT) were synthesized by Stille coupling reaction with EDOT and thiophene units as the end groups (electron donor units) and mono-nitrated benzothiadiazole and di-nitrated benzothiadiazole as the core groups (electron acceptor units). The chemical structure and optical properties of the precursor were investigated by means of 1H NMR, UV–vis absorption and fluorescence spectra; the corresponding mono-nitrated polymer films were obtained in CH2Cl2-Bu4NPF6 system by electrochemical deposition method. The optical band gap of di-nitrated polymer precursor is obviously larger than the corresponding mono-nitrated polymer precursor (both ultraviolet and fluorescence spectra are obviously blue-shifted), accompanied with the obvious increased initial oxidation potential. Due to the fluorescence quenching effect of -NO2 group, their absolute quantum yields are all very low (0.0006–0.015). The spectroelectrochemistry and electrochromic kinetics of mono-nitrated polymer films (P(Th-NO2-BT) and P(EDOT-NO2-BT)) were studied. It was found that P(EDOT-NO2-BT) can show better electrochromic performance than P(Th-NO2-BT), with dark green in the neutral state and more obvious electrochromic performance in the near-infrared region (optical contrast: 38.4 %, coloration efficiency: 129.1 cm2/C, and fast response time: 1.4 s). This systematically study about the effects of nitro substitution effect on the properties of D-A electrochromic polymers, which will further expand the selection of the new acceptor units and the application prospect of nitrated electrochromic materials.

Synthesis, structure, theoretical calculation and photocatalytic property of a novel Mn(II) supra-molecular compound containing SCN- and 2,2′-bipyridine ligands

A novel supra-molecular compound [Mn(SCN)2(byp)2] 1 (byp = 2,2′-bipyridine) was synthesized under hydrothermal conditions. Noteworthily, the SCN- in the title compound is derived from the in situ reaction of salicylaldehyde thiosemicarbazone. X-ray single-crystal diffraction analysis shows compound 1 is only a mononuclear structure, but it is expanded into a 3D supramolecular structure via H-bonds and π···π stacking. Hirshfeld Surface analysis shows C⋯H, H⋯H and S⋯H interaction are the main contribution of intermolecular interactions in the formation of compound 1. All of title compounds were characterized by IR spectroscopy, elemental analysis, XRD, XPS and TG analysis. The energy framework of compound 1 is dominated by dispersion interaction. The photocatalytic degradation ability of compound 1 for methylene blue is verified by photocatalytic degradation experiments (pH = 4: 44.6 %; pH = 7: 76.2 %; pH = 10: 78.8 %). Furthermore, the potential photocatalytic mechanism of compound 1 is inferred by UV–vis absorption spectra and Mott–Schottky curve.

Synthesis of new synthetic hybrid glasses using metallic nano-particles and rare-earth: Effect of plasmonic diluents

Borophosphate-based glass materials have the potential to revolutionize optical technology because of their outstanding optical properties, long-lasting nature, and cost-effectiveness. The present research addresses the intricate functions of rare earth and metallic nanoparticles (NPs) in borophosphate glass, which have significant potential for optical photonic and medical applications by incorporating Dy3+ ions and Cu NPs. We developed novel hybrid glasses through the melt-quenching technique, which includes the creation of functional groups and the establishment of bonds between P2O5 and B2O3, as confirmed by FTIR and Raman spectroscopy. UV–visible absorption spectra were used to identify the presence of Cu⁺ and Cu (Saeed et al., 2021) [2]⁺ ions and Cu nanoparticles, with the absorption peaks indicating their respective states. Furthermore, the underlying mechanisms of energy transfer in a glass matrix that is co-doped with dysprosium ions (Dy3+) have been studied. The experimental findings of this research not only provide valuable information about the physical properties of borophosphate glass but also emphasize the collaborative relationship between the rare-earth ion and copper nano-powders. The Tauc plot analysis demonstrated a correlation between the concentration of Cu and Dy dopants and a decrease in the energy band gap of the glass. This suggests that these dopants influence the electronic structure of the glass. This study opens up possibilities for creating innovative photonic materials with customized optical attributes.

Development of a colorimetric sensor for selective manganese detection using green-synthesized silver nanoparticles from Withania somnifera

This study reports the green synthesis of silver nanoparticles (AgNPs) using the fruit extract of Withania somnifera and their application as a colorimetric sensor for selective manganese (Mn2+) ion detection. The synthesis of AgNPs was optimized by varying pH, reaction time, and concentrations of fruit extract and AgNO3. UV–visible spectroscopy revealed that the highest absorbance of AgNPs occurred at pH 11, indicating optimal conditions for NPs formation. The absorbance behavior over time demonstrated the nucleation and stabilization processes, with optimal stability achieved after 1800 min. Increasing concentrations of fruit extract and AgNO3 enhanced NPs synthesis, reaching a plateau at 1.0 mL of extract and 1.0 mM AgNO3, respectively. Transmission electron microscopy (TEM) confirmed the formation of spherical AgNPs of 43–85 nm. Fourier-transform infrared spectroscopy (FTIR) indicated the involvement of functional groups such as O-H and C=O in the reduction and stabilization of AgNPs. The green-synthesized AgNPs exhibited notable antioxidant activity, with moderate free radical scavenging abilities compared to ascorbic acid. The colorimetric detection of Mn2+ was achieved through the aggregation of AgNPs, leading to a visible color change. UV–vis absorption spectra showed a prominent peak at 412 nm, with a linear relationship between absorbance change and Mn2+ concentration, demonstrating high sensitivity and selectivity. Comparative studies with other metal ions (Co2+, Cr3+, Ni2+) confirmed the specificity of AgNPs towards Mn2+. In conclusion, the green-synthesized AgNPs from W. somnifera offer a cost-effective and environmentally friendly approach for Mn2+ detection, with significant potential for environmental monitoring and biomedical applications.