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A tetraphenylethylene (TPE) derivative, TPEPhDAT, modified by diaminotriazine (DAT), was prepared by successive Suzuki–Miyaura coupling and ring-closing reactions. This compound exhibits aggregation-induced emission enhancement (AIEE) properties in the DMSO/MeOH system, with a fluorescence emission intensity in the aggregated state that is 5-fold higher than that of its counterpart in a dilute solution. Moreover, the DAT structure of the molecule is a good acceptor of protons; thus, the TPEPhDAT molecule exhibits acid-responsive fluorescence. TPEPhDAT was protonated by trifluoroacetic acid (TFA), leading to fluorescence quenching, which was reversibly restored by treatment with ammonia (on–off switch). Time-dependent density functional theory (TDDFT) computational studies have shown that protonation enhances the electron-withdrawing capacity of the triazine nucleus and reduces the bandgap. The protonated TPEPhDAT conformation became more distorted, and the fluorescence lifetime was attenuated, which may have produced a twisted intramolecular charge transfer (TICT) effect, leading to fluorescence redshift and quenching. MeOH can easily remove the protonated TPEPhDAT, and this acid-induced discoloration and erasable property can be applied in anti-counterfeiting.

Greenly synthesized nanoparticles have garnered attention due to their low environmental footprint, but impurities limit their applications. A novel semi-organic method for synthesizing silver nanoparticles (AgNPs) using bio-based chelating fuels (Beta vulgaris subsp., Spinacia oleracea, and Ipomoea batatas) reduces the undesirable impurities. The study also showcases the impact of bio-based chelating fuel on various characteristics of AgNPs in comparison to synthetic chelating fuel. The antimicrobial efficacy of the synthesized AgNPs in conjunction with honey was also assessed against E. coli. The XRD analysis showed cubic structure of AgNPs. The FESEM and TEM analysis showed that the well-connected spherical-shaped AgNPs (∼3–120 nm diameter) while EDS confirmed the presence of Ag in all samples. The TEM analysis also revealed layers of carbonates in AgNPs synthesized using bio-based chelating fuels. XPS investigation confirmed the absence of any prominent impurities in prepared samples and AgNPs have not experienced oxidation on their surface. However, notable surface charging effects due to the uneven conductivity of the particles were observed. The broth dilution method showed that all mixtures containing AgNPs in combination with honey exhibited a significant bacterial growth reduction over a period of 120 h. The highest growth reduction of ∼75 % is obtained for the mixture having AgNPs (Ipomoea batatas) while the least growth reduction of ∼51 % is obtained for the mixture having AgNPs (Beta vulgaris subsp.). The findings affirm that AgNPs can be successfully synthesized using bio-based chelating fuels with negligible ecological consequences and devoid of contaminants. Moreover, the synthesized AgNPs can be employed in conjunction with honey for antibacterial purposes.

In the present study, single phase nickel based disulphide (NiS2) and diselenide (NiSe2) nanostructures were prepared hydrothermally in a short time span (4 h) under subcritical temperature (160 °C). The nanostructures grow in cubic crystal phases. Average crystallite sizes and intrinsic microstrains were determined using Williamson–Hall (W–H) plot analysis. Hollow NiS2 nanospheres and bipyramidal NiSe2 nanostructures are reported that are suitable for surface related applications. Thermal gravimetric analysis (TGA) indicated high stability of the nanostructures at elevated temperatures. Optical studies indicated visible light activeness of the nanostructures exhibiting sharp band edges. The nanostructures are mesoporous in nature with NiS2 and NiSe2 having respectively a large specific surface area of 310 m2/g and 177 m2/g. A primarily work done to determine the electrochemical nature of the nanostructures showed the materials are pseudo-capacitive in nature with specific capacitances of 1022 F/g and 480 F/g respectively for NiS2 and NiSe2. The photo-catalytic activity of the nanostructures was explored against a colourless pollutant; phenol. The nanostructures degraded most of the phenol (>90 %) under visible light illumination and the reusability experiments performed determined industrial value of the photocatalysts.

Melt quenching technique was used to prepare (30-x)Li2O–xNa2O–40B2O3–30GeO2 glasses (x = 0, 5, 10, 20 & 30 mol %). The room temperature infrared spectra of the powdered glass samples were recorded in the range of 400–2000cm−1. Raman measurements were performed in the range of 200–2000cm−1 at room temperature. Raman and Infrared spectroscopy was utilized for structural study of this glass system. Specific modes of vibration and peak position were identified from de-convolution of infrared and Raman spectra using Gaussian fitting. Ge–O–Ge bonds’ symmetrical stretching vibrations related to 3 members GeO4 rings were allotted to the IR band of 483 cm−1. The strongest Raman band was allotted to symmetrical stretching vibrations of Ge–O in GeO4 having one non-bridging oxygen with 3 bridging oxygens at 797 cm−1. The observed Raman and IR spectra of various specimens are utilized here to explain the structural characteristics of current glass.

Various strategies have been adapted to fabricate stable organic-inorganic hybrid perovskite (PVT) solar cells (PSCs). The triple-cation (CH3NH3+ (MA+), CH3(NH2)2+ (FA+), and Cs+) along with dual-anion (I− and Br−)-based PVT (TC-PVT) layer offers better stability than single cation-based PVTs. The deprivation of the PVT absorber is also influenced by the interface of the absorber with the charge transport layer (electron transport layer (ETL) and hole transport layer (HTL)). Here, the degradation of the TC-PVT coated on Al-doped zinc oxide (AZO) as well as FTO/AZO/TC-PVT/HTL structured PSC was examined for various Al to Zn molar ratio (RAl/Zn) of AZO. The PL decay study of FTO/AZO/TC-PVT revealed that the lowest degradation in the power (35.38%) was observed for the AZO with RAl/Zn of 5%. Furthermore, the PV cell parameters of the PSCs were analytically determined to explore the losses in the PSCs during degradation. The shunt resistance reduction was maximum (50.32%) for RAl/Zn = 10%, whereas, minimum shunt loss (7.33%) for RAl/Zn of 2%. The highest loss due to series resistance was observed for RAl/Zn of 0%. The changes in diode ideality factor (n) and reverse saturation current density (J0) were the smallest for RAl/Znof 10%.

The structural, optical, and dielectric properties of pure NiO and yttrium (Y) doped NiO (Y: NiO) were studied in the present article for optoelectronic application. The pristine and different concentrations of 1.0, 2.5, 5.0, 7.5, and 10 wt.% doped Y: NiO nanoparticles (NPs) were synthesized by flash combustion route. X-ray diffraction patterns (XRD), Raman spectroscopy and scanning electron microscopy (SEM) images were used to study the structural properties of as-prepared nanoparticles. The average crystallite sizes (29.8–6.7 nm) and grains size (159.2–17.9 nm) were found to be decreased with an increase in Y contents. The dislocation density (1.12–21.75 × 10−3 1/nm2), lattice strain (2.79–12.46 × 10−3) and surface area (29.48–131.13 cm2/g) were increased on increasing Y contents. Direct optical band gaps of prepared samples were estimated using the Tauc's relation in the range of 3.52–3.37 eV. Photoluminescent spectra of prepared samples exhibit spectra at 355 nm, 451–482 nm, and 493 nm emission bands, which confirm the existence of oxygen and nickel vacancies. The improvement in the dielectric constant (143), dielectric loss (1233), and loss tangent (8.67) were observed for 5.0 wt.% Y doped NiO from the dielectric analysis of the samples. The electrical conductivities of Y: NiO NPs were also improved compared to pure NiO NPs. The improvement in the optical and dielectric properties of NiO in the substitution of yttrium (Y) can be used for optoelectronics applications.

Sol-gel procedure was taken into consideration to produce ferrite series with chemical formula MnYbyFe2-yO4 with y = 0.00 to 0.10 (step = 0.025). Structural, electrical and magnetic aspects of ytterbium (Yb) switched Mn-ferrites were the main focus. Every sample exhibited cubic phase spinel assembly. Exchange of ytterbium with iron in the system produced enlargement in coercivity while abridgment in remanence and saturation magnetization. Involvement of Yb ion in the ferrite assembly led to reduction of both real and imaginary constituents of permittivity. The ytterbium introduction in the lattice enhanced the value of impedance. The examination of hysteresis loop was done under the range of -2K to +2KOe. Temperature dependent resistivity, activation energy and drift mobility were carried out by two probe method. The characterization outcomes recommended that the compounds are appropriate for microwave absorption usages.

Abstract Surface area and surface active sites are two important key parameters in enhancing the gas sensing as well as photocatalytic properties of the parent material. With this motivation, herein, we report a facile synthesis of Reduced Graphene Oxide/Tungsten Oxide RGO/WO3 hierarchical nanostructures via simple hydrothermal route, and their validation in accomplishment of improved H2S sensing and highly efficient solar driven photo-degradation of RhB Dye. The self-made RGO using modified Hummer’s method, is utilized to develop the RGO/WO3 nanocomposites with 0.15, 0.3 and 0.5 wt% of RGO in WO3 matrix. As-developed nanocomposites were analyzed using various physicochemical techniques such as XRD, FE-SEM, TEM/HRTEM, and EDAX. The creation of hierarchic marigold frameworks culminated in a well affiliated mesoporous system, offering efficient gas delivery networks, leading to a significant increase in sensing response to H2S. The optimized sensor (RGO/WO3 with 0.3 wt% loading) exhibited selective response towards H2S, which is ~ 13 times higher (Ra/Rg = 22.9) than pristine WO3 (Ra/Rg = 1.78) sensor. Looking at bi-directional application, graphene platform boosted the photocatalytic activity (94% degradation of Rhodamine B dye in 210 min) under natural sunlight. The RGO’s role in increasing the active surface and surface area is clarified by the H2S gas response analysis and solar-driven photo-degradation of RhB dye solution. The outcome of this study provides the new insights to RGO/WO3 based nanocomposites’ research spreadsheet, in view of multidisciplinary applications.

This article presents the variation of structural, electronic, thermal and optical properties of a halide perovskite CsYbBr3 with increasing pressure, employing density functional theory. The pressure effect was determined in range of 0–15 GPa. In which stability of CsYbBr3 remains valid, as, verified from negative values of enthalpy of formation and phonon dispersion curves. A significant change was observed in lattice constant, bond lengths, bulk modulus and its pressure derivative, volume and ground state energy, with increasing pressure. The calculated electronic properties presented CsYbBr3 as a semiconductor with direct band gap of 3.61 eV. However, pressure rise shift the Yb-d states toward the Fermi level and causes a decrease in band gap. At 12 GPa, CsYbBr3 presents the semi metallic nature while further increase in pressure makes it as metallic. Moreover, Debye temperature (Grüneisen parameter) was observed to increase (decrease) with pressure rise while the lattice thermal conductivity was found to increase. The calculated optical properties exposed the suitability of CsYbBr3 in pressure tunable opto-electronic devices.

Silver-coated ZrO2 and individual ZrO2 nanoparticles have been synthesized using the simple reduction and co-precipitation methods, respectively. The synthesized products were examined using the X-ray diffraction, energy-dispersive X-ray and UV–visible spectroscopy, which confirmed the successful synthesis of materials. Scanning electron microscopy and transmission electron microscopy revealed the round-shaped nanoparticles of both materials. The cyclic voltammograms revealed the well-defined redox peaks and recommended the pseudocapacitive nature of the electrodes. The silver-coated zirconia showed higher specific capacitance of 792 F/g at 10 mV/s as compared to individual zirconia (10.22 F/g). Silver-coated ZrO2 also showed good power density of 274.5 W/kg at current density of 5 mA/cm2 through the galvanostatic charge discharge profile. Hence, the results suggest that silver-coated ZrO2 showed improved electrochemical performance as compared individual ZrO2 due to higher electrical conductivity and specific surface area. Hence, silvercoated ZrO2 nanoparticles can be employed as an electrode material for supercapacitor applications.

The solar cells and thermoelectric generators are the main sources of renewable energy. In current article, we have analyzed the electronic, optical, and transport characteristics of K2TiI6 and Rb2TiI6 by density functional theory (DFT) based Wien2k code through modified Becke and Johnson (mBJ) potential. The structural and thermodynamic stability are certified by tolerance factor (0.99–1.0) and negative formation energy. The bonding nature is illustrated by color charge density. The band gap of 1.39 eV and 1.48 eV for K2TiI6 and Rb2TiI6 demonstrate the maximum absorption of light takes place in visible region (1.5 eV–3 eV), which makes them new potential materials for solar cells. Moreover, the reflection of light and optical loss is negligible in the visible region. The transport characteristics have been explained by classical Boltzman transport (CBT) based BoltzTraP code in terms of thermal to electrical conductivity ratio, Seebeck coefficient, and figure of merit. The figure of merit lies between 0.75 to 0.76, which is decent for thermoelectric characteristics.

Modification of conventional photoanode with oxide nanoparticles is a practical tactic to improve the performance of electrochemical devices. In this study, erbium oxide (Er2O3) nanoparticles were mixed with the TiO2 paste and photovoltaic performance of the dye-sensitized solar cell (DSSC) was investigated. The highest power conversion efficiency of 6.39% was reached with the 1 wt.% of Er2O3 in photoanode, while in the similar condition the device with the pure TiO2 photoanode achieved the power conversion efficiency of 3.54%. This improvement in the power conversion efficiency was attributed to declining in charge recombination, improved open-circuit voltage and short-circuit current due to the presence of the critical amount of Er2O3. XPS analysis confirms the structural coherence between the Er2O3 and TiO2, which enhanced the optical performance of the composite photoanode. Composite photoanodes were further characterized by FESEM-EDX, XRD, and AFM for structural and morphological studies.

Exploring the cost-effective and environment-friendly two-dimensional materials for miniaturized portable device applications has received remarkable attention in recent years. In this article, we explore two new atomically thin polymorphs of ZnO derived from the pressure-driven rock salt (NaCl) and GeP- Phases. These 2D ZnO structures are originated from the 110-facet of NaCl- and GeP-like ZnO polymorphs employing a vacuum 20 Å separation. The energy stability, structural parameters, electronic structure, and optical spectra of these 2D ZnO polymorphs have been comprehensively studied from first-principles calculations. The two monolayers of ZnO exhibited energetic stability as large as their bulk counterparts. Similarly, following their bulk counterparts, both monolayers are found semiconductors of indirect bandgap nature with Eg of 1.06 and 2.55 eV as estimated theoretically for NaCl-and GeP-types of ZnO monolayers, respectively. The two monolayers demonstrated optical absorption as high as 35.61 × 104 cm−1 and 30.26 × 104 cm−1 for NaCl-ZnO and GeP-ZnO respectively. Moreover, NaCl-ZnO yields transparency over infrared, visible, and UV light regions below the energy of 8.0 eV, whereas GeP-ZnO possesses transparent nature below ~ 12 eV of the electromagnetic spectrum. Overall, these ZnO monolayers exhibit relatively small optical reflection, considerable refraction, and significant absorption indicating that a large portion of incident UV light is absorbed by these monolayers. This study is believed to unveil the potential of these two monolayers of ZnO for nanoscale electronic, optoelectronic, and photovoltaic applications.