Space Group Research Articles

Phase identification and photophysical characteristics of vanadate-based nanophosphors for lighting and latent fingerprinting applications

Monoclinic structure-based Er3+-activated Ba2BiV3O11 nanophosphors have been developed via an easy and cost-efficacious urea-aided solution combustion (SC) procedure. Various spectroscopic and structural investigations thoroughly examine the produced powders. The crystal structure has been resolved by employing a combination of X-ray diffraction (XRD) and the Rietveld refinement practice. The developed powdered nanosamples are crystallized in a monoclinic crystal system with P21/a space group. Further, to evaluate the composition of elements and their relative distribution, energy dispersive X-ray (EDAX) analysis was performed. The band gap values for the host matrix and the optimal nanophosphors were measured using a DR spectrophotometer; the obtained values were 3.47 eV and 3.40 eV, respectively. The strongest excitation peak at 381 nm is closely-matched with the characteristic wavelength of commercialized near ultraviolet (NUV) based LEDs. The characteristic emission spectra of Ba2Bi1-xErxV3O11 (x = 0.01–0.1) phosphors show the strongest emission at 553 nm (4S3/2 → 4I15/2). Additionally, photometric parameters such as quantum efficiency (86 %), color coordinates (x = 0.2568 and y = 0.4551), and correlated color temperature (CCT = 7722 K) are obtained from PL data and are strongly advised for use in wLEDs, color displays, imaging, lighting, and latent fingerprint applications.

Investigating the Formation of Different (NH4)2[M(H2O)5(NH3CH2CH2COO)]2[V10O28]·nH2O (M = CoII, NiII, ZnII, n = 4; M = CdII, MnII, n = 2) Crystallohydrates

Three hybrid compounds based on decavanadates, i.e., (NH4)2[Co(H2O)5(β-HAla)]2[V10O28]·4H2O (1), (NH4)2[Ni(H2O)5(β-HAla)]2[V10O28]·4H2O (2), and (NH4)2[Cd(H2O)5(β-HAla)]2[V10O28]·2H2O (3), (where β-Hala = zwitterionic form of β-alanine) were prepared by reactions in mildly acidic conditions (pH ~ 4) at room temperature. These compounds crystallise in two structure types, both crystallising in monoclinic P21/n space group but with dissimilar cell packing, i.e., as tetrahydrates (1 and 2) and as a dihydrate (3). An influence of crystal radii and spin state of the central atom in [M(H2O)5(β-HAla)]2+ complex cations on the crystal packing leading to the formation of different crystallohydrate forms was investigated together with previously prepared (NH4)2[Zn(H2O)5(β-HAla)]2[V10O28]·4H2O (4) and (NH4)2[Mn(H2O)5(β-HAla)]2[V10O28]·2H2O (5) and spin states of [M(H2O)5(β-HAla)]2+ (M = Co2+, Ni2+, and Mn2+) cations in solution were confirmed by 1H-NMR paramagnetic effects. FT-IR and FT-Raman spectra for 1–5 are in agreement with the X-ray structure analysis results.

“Yb modification of bismuth Ferrite: Unveiling Optical, Dielectric, and electrochemical properties for advanced applications”

This study explores the detailed impact of Yb3+ substitutional doping on the structural, optical, dielectric, and electrochemical characteristics of bismuth ferrite. Rigorous structural analysis conducted via X-ray diffraction confirmed the formation of a rhombohedral distorted perovskite structure, within the R3C space group. The investigation of crystallite size showed a reducing trend as Yb3+ content increased. Morphological studies revealed the presence of finely dispersed nanocrystalline grains, exhibiting particle size within the range from 281 to 197 nm. Raman spectroscopy unveiled notable phonon mode shifts towards higher wavenumbers, correlating with increased Yb3+ doping concentrations. Additionally, a discernible reduction in bandgap energy, from 2.15 to 1.98 eV, was observed with increasing doping levels. An improved dielectric response was observed with Yb3+ doping. Electrochemical assessments, employing cyclic voltammetry and galvanostatic charge–discharge techniques, revealed the superior electrochemical performance of the 30 % Yb-doped bismuth ferrite-modified electrode, demonstrating a specific capacitance of 575 Fg−1 at a scan rate of 10 mVs−1. These findings underscore the tailored engineering of Yb-doped bismuth ferrite nanoparticles, positioning them as promising candidates for the next generation of supercapacitor devices.

Synthesis and crystal structure of new Mn (III) complex; a target catalyst for direct conversion of thiols after heterogenization

In this study, we are interested in the synthesizing of a new water-soluble complex of Mn (III) formulated as [Mn(pzo)(dipic)(H2O)2]2·3H2O; hereafter referred to as complex 1 where pzo− = pyrazonate and dipic2− = pyridine-2,6-dicarboxylate, under hydrothermal conditions. The molecular structure of complex 1 is primarily determined by single crystal X-ray diffraction (SC-XRD) which shows two mono-nuclear complexes of Mn (III) with three lattice water molecules. According to SC-XRD, complex 1 crystallizes in space group P1¯ of a triclinic system. The center of Mn (III) is seven-coordinated with a distorted pentagonal-bipyramidal geometry with three oxygen atoms and two nitrogen atoms in the equatorial plane. Two oxygen atoms of two water molecules are coordinated in the axial positions. In addition, the structure of complex 1 has been studied by elemental analysis (CHN), Fourier-transform infrared spectroscopy (FT-IR (, thermogravimetric analysis/differential thermal analysis/differential thermogravimetry (TGA/DTA/DTG). Complex 1 has been immobilized on the silica-coated Fe3O4 nanoparticles to produce an efficient and recyclable heterogeneous catalyst formulated as Fe3O4@SiO2@1; hereafter referred to as catalyst 1. Catalyst 1 was characterized by inductively coupled plasma optical emission spectrometry (ICP-OES), energy-dispersive X-ray spectrometer (EDS), FT-IR, scanning electron micrograph (SEM), powder X-ray diffraction pattern (PXRD), and Brunner-Emmet-Teller (BET). 1 was used as a new heterogeneous catalyst for the oxidative coupling of thiols to their corresponding disulfides using 30 % H2O2. Under optimum reaction conditions, catalyst 1 exhibited high catalytic activity. 1 can be recovered by a magnet and reused for at least 7 consecutive cycles without significant loss of catalytic performance.

Crystal engineering with novel antipyrine derivatives: Insights from X-ray diffraction, Hirshfeld surface analysis, and DFT calculations on intermolecular interactions

In this study, we report the synthesis, structural characterization by X-ray diffraction, vibrational (Infrared and Raman) investigation, Hirshfeld surface analysis, and DFT calculations of three new antipyrine derivatives (1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) bearing amide groups (1–3). The compounds were synthesized in good yields and characterized spectroscopically. X-ray diffraction revealed that compound 1 crystallizes as a monohydrate in the monoclinic space group P21/c, while compound 3 also crystallizes as a monohydrate in the orthorhombic space group Pccn, exhibiting quasi-isomorphism with 1. Compound 2 crystallizes in the P21/c space group, forming H-bonded centrosymmetric dimers. The crystal packing is stabilized by NH···O and CH···O hydrogen bonds, along with CH···π interactions. FTIR and Raman spectroscopic analysis, supported by DFT calculations, identified key vibrational modes in the amide and pyrazole moieties. Hirshfeld surface analysis indicated that the molecular sheets are primarily formed by hydrogen bonds, with stabilization dominated by electrostatic energy contributions. DFT calculations (PBE0-D3/def2-TZVP) and QTAIM/NCIplot analyses revealed that the H-bonding interactions are energetically significant.

Complex magnetic ordering in the noncentrosymmetric metal PrCuGe3

We report on the successful synthesis of PrCuGe3 which crystallizes in the tetragonal BaNiSn3-type structure (space group: I4mm) with lattice parameters, a = 4.1470(2) Å and c = 10.185(3) Å. The material is characterized using dc magnetic susceptibility χ(T), ac magnetic susceptibility χac(T), isothermal magnetization M(B), specific heat Cp(T), and electrical resistivity ρ(T) measurements. PrCuGe3 undergoes a long-range ferromagnetic ordering at TC = 23 K, which is followed by another transition below Ttr = 17 K. TC has a quite small anomaly in Cp(T) and ρ(T) despite displaying large associated anomalies in both χ(T) and χac(T) and a sizable ferromagnetic ordered moment. Instead the transition at Ttr has a much larger anomaly in Cp(T) and ρ(T) but essentially no signal in χ(T) and χac(T). Such observations in PrCuGe3 are nontrivial. A Sommerfeld coefficient γ = 375 mJ/(mol K2) is extracted from specific heat which indicates a significant enhancement of the quasi-particle mass at low temperature. Hence, PrCuGe3 exemplifies a system with the coexistence of complex magnetic ordering and a putative heavy-fermion state.

Analogous Chain Selenite Chlorides Ba2M(SeO3)2Cl2 (M = Cu2+, Ni2+, Co2+, Mn2+) and Pb2Cu(SeO3)2Cl2 with Tunable Spin S: Syntheses and Characterizations.

A series of analogous chain selenite chlorides Ba2M(SeO3)2Cl2 (M = Cu 1, Ni 2, Co 3, Mn 4) and Pb2Cu(SeO3)2Cl2 5 with tunable spin S from S = 1/2 to S = 5/2 have been hydrothermally synthesized and characterized. These analogues crystallized in the orthorhombic Pnnm space group (monoclinic P21/n space group for 5) all containing M2+-SeO3-M2+ spin chains, which are further separated by the Ba2+ ions (Pb2+ for 5). The magnetic susceptibility results of 1, 2, and 5 show broad maxima around 80.0, 18.9, and 78.0 K, respectively, indicating good one-dimensional (1D) magnetism. Meanwhile, no long-range order (LRO) is observed down to 2 K for both 1 and 5, while the isostructural compounds 2, 3, and 4 exhibit LRO at 3.4 K, 10.8 K, and 5.7 K, respectively, which are further confirmed by the heat capacity and electron spin resonance results, as well as the observed spin-flop transitions in the M-H curves measured at 2 K below TN. The magnetizations of 1-5 at 7 T are still far from saturation. In addition, thermal stability and FT-IR and UV-vis-NIR spectroscopy of 1-5 are reported.

Structural and optical properties of green-synthesised tricobalt tetroxide nanoparticles

In this study, we investigated the structural and optical properties of garlic extract-based green-synthesised tricobalt tetroxide nanoparticles. Transmission electron microscopy revealed a particle size range of 8–22 nm for the prepared powder sample. Powder x-ray diffraction data and Rietveld refinement results confirmed the spinel cubic crystal structure of the tricobalt tetroxide nanoparticles, with an average crystallite size of 11.23 nm. This crystal structure corresponds to the Fd3̅m space group and has an average lattice constant of 0.791 nm. The bond lengths of Co3+–O2− and Co2+–O2− are measured to be 0.188 nm and 0.190 nm, respectively. The FTIR data provided evidence of the presence of various functional bands, which helped qualitatively determine the purity of the sample. The UV–vis spectrum estimated two direct energy band gap values (3.7 eV and 2.2 eV) that may be useful for efficient interaction with a wide range of ray spectra to create more electron–hole pairs for various photo-responsive applications, such as dye degradation, solar cells, and optoelectronic components.

A Rare-Earth-Based Borate Optical Crystal with Enlarged Dihedral Angles of Distinct [BO3] Groups Exhibiting a Wide UV Transparent Range.

Borates, as advanced optical materials, have garnered wide interest due to their diverse structural configurations and great potential for applications in the ultraviolet (UV) regions. Herein, we synthesized a new rare-earth borate crystal, namely, K2NaYB2O6, which is classified as one of the ABReB2O6 compounds, where A and B represent alkali metal and Re denotes rare-earth metal. K2NaYB2O6 adopts in the monoclinic space group P21/c (No. 14), showcasing a three-dimensional (3D) framework composed of a planar triangular configuration of [BO3] units and distortive [YO7] polyhedra. Notably, both dihedral angles between distinct [BO3] units reach 79.6°, which represents an unprecedented structural feature in monoclinic ABReB2O6-type crystals. Moreover, the compound has a short UV absorption edge at around 204 nm, corresponding to a wide band gap of approximately 5.67 eV. Additionally, it possesses a moderate birefringence of 0.028 at 1064 nm. Further analysis utilizing theoretical calculations suggests that the optical behaviors of K2NaYB2O6 are mainly governed by its basic structural unit [BO3] triangles and distorted [YO7] polyhedra. These findings enrich the structure chemistry of rare-earth borates and offer valuable insights for the design of optical crystals in the UV wavelength range.

(η6-Benzene)-chlorido-[(S)-2-(4-isopropyl-4,5-di-hydro-oxazol-2-yl)phenolato]ruthenium(II).

The title compound, [Ru(C12H14NO2)Cl(η6-C6H6)], exhibits a half-sandwich tripod stand structure and crystallizes in the ortho-rhom-bic space group P212121. The arene group is η6 π-coordinated to the Ru atom with a centroid-to-metal distance of 1.6590 (5) Å, with the (S)-2-(4-isopropyl-4,5-di-hydro-oxazol-2-yl)phenolate chelate ligand forming a bite angle of 86.88 (19)° through its N and phenolate O atoms. The pseudo-octa-hedral geometry assumed by the complex is completed by a chloride ligand. The coordination of the optically pure bidentate ligand induces metal centered chirality onto the complex with a Flack parameter of -0.056.

Copper molybdenum sulfide coupled with multi-walled carbon nanotube nanocomposite for robust water splitting process

Developing eco-friendly and efficient non-noble catalysts is crucial for cleaner energy production, nevertheless, optimizing the catalyst is challengeable. The Cu2MoS4 were successfully synthesized with various amount of MWCNTs. The suitable amount of high conductivity of MWCNT can greatly accelerate its HER and OER kinetics, which was demonstrated with the obtained results. XRD spectra revealed tetragonal Cu2MoS4 structure with I 4‾ 2 m space group. Carbon existence was substantiated by Raman spectra, and the ID/IG value of Cu2MoS4/MWCNT-100 was 0.98. The Cu2MoS4 nanoplates were strongly anchored to MWCNTs, as demonstrated by the morphological analysis of SEM and TEM images. The optimized catalyst (denoted as Cu2MoS4/MWCNT-100) exhibits high bifunctional with low 140 mV overpotential value and 193 mV@10 mA/cm2 for HER and OER and a lower Tafel slope value of 93 mV/dec and 51 mV/dec for HER and OER. Moreover, it revealed good catalytic activity with high electrical conductivity (0.361 Ω and 0.897 Ω for HER and OER) and high capacitance value (5.9 mF/cm2 and 9.4 mF/cm2 for HER and OER) with better stability. Lastly, we construct overall water splitting electrolyzer by optimized electrocatalyst as both anode and cathode entail cell voltage as 1.57 V only to deliver 10 mA/cm2 with a faradaic efficiency of 98.75 % for H2 and 93.28 % for O2 and it was believed as active material for water splitting.

Electrical conductivity and relaxation mechanisms of nanocrystalline Ba0.75Ca0.2Cs0.05TiO3

Ca and Cs doped barium titanate lead-free ceramic with the formula Ba0.75Ca0.2Cs0.05TiO3 has been prepared by the solid-state reaction method. X-ray diffraction (XRD) confirms the crystallization of the sample in a tetragonal structure with a P4mm space group. The phase purity and grain morphology were evaluated using X-ray diffraction and scanning electron microscopy (SEM). The material exhibits a primary phase of Ba0.75Ca0.2Cs0.05TiO3 with a minor secondary phase of BaO2, and the average grain size is determined to be 1.66 μm. Using non-destructive complex impedance spectroscopy (CIS), we extensively studied the electrical behavior, including complex impedance (Z*), complex modulus (M*), electrical conductivity, and relaxation mechanisms, of Ba0.75Ca0.2Cs0.05TiO3 over a wide temperature (85 K–290 K) and frequency range. The ac conductivity analysis reveals that the dominant conduction mechanism is the non-overlapping small polaron tunneling (NSPT) model. The impedance analysis indicates a single semi-circle in the real and imaginary parts, suggesting a single relaxation mechanism. Additionally, the activation energy was calculated to be approximately 0.0489 eV. These findings contribute to the understanding of the structural and electrical properties of Ba0.75Ca0.2Cs0.05TiO3, highlighting its potential applications in electronic devices such as capacitors, thermistors, and ferroelectric random access memories (FRAMs).

Synthesis of Zintl Phase Metal Silicide Thermoelectric Materials in Magnesium/Zinc Flux.

Zintl phases have potential applications as thermoelectric materials for power generation and cooling owing to their complex crystal structures and unique electronic properties. We carried out reactions of silicon with barium and strontium in excess Mg/Zn flux to synthesize (Ba/Sr)5+xMg19-xSi12 Zintl phases, investigating the effect of varying Ba/Sr ratio on site mixing and thermoelectric properties. (Ba/Sr)5+xMg19-xSi12 compounds with 0 < x < 3 are charge-balanced Zintl phases which adopt the hexagonal Ho5Ni19P12 structure type (space group P6̅2m). Density of states calculations indicate that these materials are semimetals. Single-crystal X-ray diffraction data and elemental analysis for Ba5Mg19Si12, Ba4.86Sr2.94Mg16.20Si12, Ba3.63Sr4.20Mg16.17Si12, Ba1.93Sr5.99Mg16.08Si12, and Sr7.82Mg16.18Si12 show occupation of barium and strontium cations in Ho sites, while strontium mixes with magnesium on a specific Ni site. Powder XRD data of products show that they are single phase throughout the sample. Thermoelectric measurements indicate that increasing strontium content and mixing on three cation sites decreases thermal conductivity; it is hypothesized that improved overall thermoelectric behavior is likely due to the rattling of the Sr cations in their positions.

Na3Sc(PO4)2: Thermal behaviors, distorted β-K2SO4-type structure and dielectric properties

The Na3Sc(PO4)2 (NSPO) compound was obtained by solid-state synthesis method and has a new type of distorted β-K2SO4 (arcanite) crystal structure that was refined based on powder XRD data in the space group (SG) P21/c, with unit cell parameters: a = 11.5533(1) Å, b = 5.31759(5) Å, c = 16.7650(2) Å, β = 97.6439(6)°. The NSPO is a metastable phase with an optimal synthesis temperature range between 1173 and 1233 K. When a mixture of Na2CO3, NH4H2PO4 and Sc2O3 is annealed below this temperature range, the NaSICON-type compound and Na-polyphosphates is formed. However, annealing above T∼1245 K leads to the decomposition onset into the NaSICON-type compound (Na3Sc2(PO4)3), Na3PO4 and terminates at T∼1289 K. NSPO phase is dielectric with σbulk = 4.4 × 10−7 S/cm at 300 K. Increasing the temperature from 300 to 1000 K leads to an increase in σbulk by four orders (σbulk = 5.6 × 10−3 S/cm at 1000 K).

Preparation and properties of CsMoO2F3:Mn4+ red phosphor with anti-thermal quenching and high color rendering index

The CsMoO2F3:Mn4+ red phosphors were prepared by the lower coprecipitation method. The XRD data of the powder were refined by Rietveld using GSAS software. The crystal structure of the powder was orthogonal structure, and the space group was Imma. The strongest excitation band of the sample was located at 468 nm and the strongest emission band at 633 nm. When the Mn4+ doping ratio was 11 %, the CsMoO2F3:Mn4+ red phosphor had the strongest luminescence intensity with a color purity of 99.25 %. CsMoO2F3:Mn4+ red phosphor mixed with commercial YAG:Ce3+ yellow phosphor was coated on a blue LED chip and encapsulated into a white LED. The resulting device at a drive current of 50 mA had a 95.0 color rendering index and a correlated color temperature of 4320 K, with a radiant luminous efficacy of 356.3 lm/W. CsMoO2F3:Mn4+ red phosphor had better thermal stability than the previous Mn4+-doped fluorine oxide phosphors. At 423 K, the luminous intensity at this time was 117 % of that at room temperature (303 K), with excellent heat resistance.

Insights into Co (II)-based hybrid materials for photocatalytic and antioxidant applications

Metal-organic materials are widely used as scaffolds to create porous materials for various applications. However, research on solid compositions from hybrid materials (HB) is limited. This study examines two hybrid components using spectroscopic techniques and single crystal X-ray diffraction. The crystal structure analysis reveals a monoclinic system for compounds Co(HCO2)2·2H2O (I) and (C6H10N2)2[CoCl4]Cl2 (II) in the P21/c space group. Compound I features cobalt octahedra with coordinated formate ions and water molecules, while compound II contains organic cations, anions, and free chlorides with interconnected structural motifs. UV light at 400 nm induces high photocatalytic activity in both complexes, leading to significant degradation rates within 80 minutes. Trapping experiments identify activated species as h+ and •O2−. Antioxidant activity assessments highlight their antioxidative potentials.

One-step synthesis of 2-Methyl-2,4-Diphenyl-2,3-Dihydro-1H-Benzo[b][1,4]diazepine: Investigating crystal structure, hirshfeld surface analysis and supercapacitor applications

This study reports the synthesis, spectroscopic characterization and detailed crystal structure analysis of a benzodiazepine compound, 2-methyl-2,4-diphenyl-2,3-dihydro-1H-benzo[b][1,4]diazepine, synthesized from 1,2-phenylenediamine and acetophenone. The crystal structure, determined via single crystal X-ray analysis, reveals the compound's placement within the monoclinic system with the P 21/c space group. The asymmetric unit comprises the main molecule and an uncoordinated water molecule linked through an intramolecular O–H···N hydrogen bond. The crystal packing is influenced by centrosymmetric dimers formed by uncoordinated water molecules through O–H···N hydrogen bonds, along with weak C–H···π interactions. Hirshfeld surface analysis highlights the significance of H … H and H … C/C … H interactions in the crystal packing, providing insight into the intermolecular forces at play. Supercapacitance performance of the GCPE/LDABA electrode was assessed and specific capacitance value of 17.89 mF g−1 was achieved in a 0.1 M Na2SO4 electrolyte. Long-term stability of the GCPE/LDABA electrode was maintained up to 2000 cycles. This study not only elucidates the structural features of the title compound but also sheds light on its potential utility through an investigation into its electrochemical performance via supercapacitor application.

Design and construction of bio carbon derived Bi2Fe4O9 nanocomposites sensor for clad modified optical fiber sensors for detection of ethanol gas

Bio carbon (BC) derived Bi2Fe4O9 hybrid sensor was fabricated via sonochemical approach. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and N2 adsorption-desorption were used to determine the structural, morphological and porosity characteristics, respectively. The materials' gas-sensing properties were evaluated using a clad-modified optical fiber sensor. The orthorhombic structure with Pbam space group of Bi2Fe4O9 confirmed by the relative diffraction pattern. All sharp intense diffracted patterns might be indexed based on the standard value ((JCPDS card No. 74-1098). Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images illustrate those granular sheets with aggregated spherical shaped morphology of BC and Bi2Fe4O9, respectively. The pristine Bi2Fe4O9 exhibits Raman modes at 378 cm−1 and 617 cm−1, which is ascribed to the orthorhombic structure. The orthorhombic structure was already confirmed from XRD results. BFOG5 sample shows high SSA (107.5 m2/g) and pore size (38.4 nm), which is nearly 2.2 times greater than that of pristine Bi2Fe4O9 (54.3 m2/g and 23.4 nm). Fiber optic sensor was fabricated and tested for ethanol gas with various gas concentrations (0–500 ppm). The sensitivity (defined as slope of fitted line) enhanced from 14.69 (count/%) for bare Bi2Fe4O9 to 33.94 (count/%) for Bi2Fe4O9/BC (BFOG5). The response and recovery time was 25 s and 20 s for Bi2Fe4O9/BC (BFOG5) sensor, which is higher than that of bare Bi2Fe4O9 (42 s and 33 s). Our findings pave the way for a unique hybrid Bi2Fe4O9/BC composite to be used in a highly sensitive C2H5OH gas sensor system at RT.

The novel cocrystals of acacetin with 4,4′-bipyridine and 2,2′-bipyridine: Crystal structures analysis, stability and dissolution evaluation

To our best knowledge, acacetin has great potential for market development and clinical application due to its various pharmacological effects including antioxidant, anti-inflammatory, anti-cancer, neuroprotective, hepatoprotective, cardioprotective and so on. However, low solubility and poor bioavailability overshadow its prospect for new drug development and application. In order to optimize the solubility of acacetin, a scientific and reasonable cocrystal design was launched. In this study, the cocrystal of acacetin-4,4′-bipyridine and acacetin-2,2′-bipyridine were successfully prepared and systematically characterized by single-crystal X-ray diffraction, powder X-ray diffraction, fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis. With the efforts of structural analysis and theoretical calculation, it was found that the two formed cocrystals including acacetin-4,4′-bipyridine and acacetin-2,2′-bipyridine possessed significant distinctions in terms of the type of space group and crystal system, the lattice arrangement as well as the forces and hydrogen bonds connections involved in the generation of cocrystals. By the evaluation of stability and dissolution, the results indicated that two cocrystals could keep stable under high temperature, high humidity as well as light condition and significant enhancement in the solubility and dissolution rate of acacetin were achieved by the formation of two new cocrystals which might be contributed to the increase of its bioavailability. This study was of significance to not only investigate the differences of two cocrystals in the aspects of space group, lattice arrangement, intermolecular force and thermodynamic stability, but also provided a new approach to optimize the solubility of acacetin.

Gompherna globosa flower extract-driven ZnO nanoparticles for enhanced antimicrobial and photocatalytic properties

The aqueous extract of Gomphrena globosa flowers was utilized for the first time as an effective capping and reducing agent for the synthesis of zinc oxide nanoparticles (ZnO NPs). The synthesized nanoparticles were examined using x-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive x-ray analysis (EDAX), Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) and UV–vis spectroscopy. XRD revealed the single-phase wurtzite structure of ZnO nanoparticles with a P63mc space group with an average size of 23 nm. The band gap of synthesized ZnO nanoparticles was determined as 3.16 eV from UV–vis spectroscopy. The rod-shaped structure of the synthesized ZnO NPs was revealed by SEM. The presence of the elements Zn & O was confirmed by EDAX. TEM and SAED confirmed that the average particle size was 26 nm and that the material was polycrystalline. The bio-inspired ZnO NPs achieved outstanding degradation activity of 95.4% against Malachite Green dye after 20 min of UV illumination. The antibacterial properties of the green synthesized nanoparticles were assessed in relation to gram-positive (Staphylococcus sp., Bacillus sp.,) and gram-negative (E. coli, Klebsiella sp.) bacteria. ZnO nanoparticles possess strong antifungal property against a pathogenic fungus Aspergillus niger. This study shows that green-synthesized ZnO nanoparticles derived from Gomphrena globosa flower extract are recommended for use in anti-microbial and photocatalytic applications.