Boosting the performance of LaCoO3/MoS2 perovskite interface for sustainable decontaminants under visible light-driven photocatalysis

The novel composite LaCoO3/MoS2 hybrid nanostructure was synthesized via a combination of sol-gel, hydrothermal, and ultrasonication methods. Alizarin Red S (ARS) and Rhodamine B (RhB) were employed as a model pollutant, to assess the photodegradation efficiency of synthesized catalysts. The effect of MoS2 (2.5%, 5%, 7.5%, and 10%) on LaCoO3 (LCO) and its photocatalytic performance was studied. The properties of synthesized catalysts were assessed using various material characterization techniques. The photocatalytic dye degradation of ARS and RhB was investigated under visible light. Among the synthesized catalyst LM-5% composite (LaCoO3 with 5% MoS2) is determined to be the best photocatalyst as it degrades 96 % (ARS) and 90 % (RhB) in 40 min and 80 min, respectively. The photocatalyst is stable even after multiple runs and exhibits negligible loss in degradation efficiency during the cyclic test. Trapping experiments reveal the significance of superoxide anion and hydroxyl radicals against the photodegradation of ARS and RhB. The kinetics of photodegradation of ARS and RhB by LM-5% is found to be 5.70 × 10-2 and 2.25 × 10-2 min-1, respectively. Herein, we demonstrated a catalyst possessing excellent photodegradation activity which may ignite the possibilities of using efficient photocatalysts for environmental remediation.

Enhanced photocatalytic activity of ZnO hexagonal tube/r-GO composite on degradation of organic aqueous pollutant and study of charge transport properties

ZnO hexagonal tube and ZnO/r-GO nanocomposites were synthesized by hydrothermal method and the nanostructures were characterized by XRD, UV-DRS, PL, FTIR, FESEM, and TEM techniques. The main violet emission peak of the synthesized nanostructures is due to the transition between interstitial zinc and hole (valence band) of ZnO. The potential of ZnO/r-GO nanocomposite was evaluated using methyl orange (MO) and rhodamine-B (RhB), and the results were compared with the activity of synthesized ZnO nanostructures. More than 95% of MO and RhB were by ZnO/r-GO nanocomposite and it was found to be higher than that of ZnO hexagonal tube. The degradation MO and RhB were found to follow first-order kinetics and it has a rate constant of 7.68 × 10^-2and 7.83 × 10^-2 min^-1, respectively. These results are mainly due to the enhanced charge transport property. Trapping experiments show that superoxide radical anion and hydroxide radicals are chief species responsible for the degradation of MO and RhB. The chemical stability of the nanocomposite was evaluated by cycle test experiments and it reveals that the catalyst can be reused up to few cycles without considerable loss of photocatalytic activity. This work affords a simple stratagem to integrate ZnO hexagonal tubes and r-GO nanosheets to construct effective catalysts for the degradation of organic compounds.

Investigation on the structural, linear/nonlinear optical and electrical characteristics of Cd- and Mn-doped polar lithium sulfate monohydrate crystals

Doped LSMH single crystals exhibited good transmittance percentage, lower birefringence, enhanced SHG efficiency and good piezoelectric response compared to undoped LSMH crystals.

Enhanced visible light induced photocatalytic activity on the degradation of organic pollutants by SnO nanoparticle decorated hierarchical ZnO nanostructures

One (1D) and two-dimensional (2D) nanostructures of zinc oxide and tin oxide (ZnO/SnO) nanocomposites were synthesized by a hydrothermal method using ethylenediamine (EDA) as a capping ligand.

Studies on the growth, spectral, structural, electrical, optical and mechanical properties of Uronium 3-carboxy-4-hydroxybenzenesulfonate single crystal for third-order nonlinear optical applications

Organic Uronium 3-carboxy-4-hydroxybenzenesulfonate (UCHBS) nonlinear optical single crystal was grown by solution growth technique. The solubility and nucleation studies were performed for UCHBS at different temperatures 30, 35, 40, 45, 50 and 55°C. The crystal structure of UCHBS was elucidated from single crystal X-ray diffraction study. High resolution X-ray diffraction technique was employed to study the perfection and internal defects of UCHBS crystal. Infrared and Raman spectra were recorded to analyze the vibrational behavior of chemical bonds and its functional groups. The physico-chemical changes, stability and decomposition stages of the UCHBS compound were established by TG-DTA studies. The dielectric phenomenon of UCHBS crystal was studied at different temperatures with respect to frequency. Linear optical properties of transmittance, cut-off wavelength, band gap of UCHBS were found from UV-visible spectral studies. Third-order nonlinear optical susceptibility, nonlinear refractive index, nonlinear optical absorption coefficient values were measured by Z-scan technique. The mechanical properties of UCHBS crystal was studied by using Vicker's microhardness test. The growth features of UCHBS crystal were analyzed from etching studies.

Studies on the growth, structural, spectral and third-order nonlinear optical properties of ammonium 3-carboxy-4-hydroxy benzenesulfonate monohydrate single crystal

An organic nonlinear optical bulk single crystal, Ammonium 3-carboxy-4-hydroxy benzenesulfonate monohydrate (ACHBS) was successfully grown by solution growth technique. Single crystal X-ray diffraction study confirms that, the grown crystal belongs to P21/c space group. Powder X-ray diffraction and high resolution X-ray diffraction analyses revealed the crystallinity of the grown crystal. Infrared spectral analysis showed the vibrational behavior of chemical bonds and its functional groups. The thermal stability and decomposition stages of the grown crystal were studied by TG-DTA analysis. UV-Visible transmittance studies showed the transparency region and cut-off wavelength of the grown crystal. The third-order nonlinear optical susceptibility of the grown crystal was estimated by Z-scan technique using He-Ne laser source. The mechanical property of the grown crystal was studied by using Vicker's microhardness test.

Study on structural, morphological, optical and thermal properties of guanidine carbonate doped nickel sulfate hexahydrate crystal

The single crystal of guanidine carbonate doped nickel sulfate hexahydrate was grown from solution for ultraviolet filters. The single crystal XRD confirms that the grown single crystal belongs to the tetragonal system with the space group of P4₁2₁2. The crystallinity of the grown crystal was estimated by powder X-ray diffraction studies. The optical transmission and thermal stability of as-grown guanidine carbonate doped nickel sulfate single crystals have been studied. The optical transmission spectrum demonstrates the characteristics of ultraviolet filters. The TG/DTA studies confirm the thermal properties of grown crystals. Thermo-gravimetric analysis showed that the dehydration temperature of the guanidine carbonate doped nickel sulfate crystal is about 100 °C, which is much higher than that of pure nickel sulfate hexahydrate (NSH) crystals which is 72 °C. The growth behaviors and dislocation density were detected under the high resolution XRD and etching studies respectively.

Crystal structure of 4-(dimethylamino)pyridinium 4-aminobenzoate dihydrate

In the title hydrated molecular salt, C7H11N2+·C7H6NO2−·2H2O, the cation is protonated at the pyridine N atom and the dihedral angle between the benzene ring and the CO2−group in the anion is 8.5 (2)°. In the crystal, the cation forms an N—H...O hydrogen bond to the anion and the anion forms two N—H...O hydrogen bonds to adjacent water molecules. Both water molecules form two O—H...O hydrogen bonds to carboxylate O atoms. In combination, these hydrogen bonds generate a three-dimensional network and two weak C—H...π interactions are also observed.

Controlled synthesis of organic ligand passivated ZnO nanostructures and their photocatalytic activity under visible light irradiation

Zinc oxide (ZnO) nanostructures were synthesized and their photocatalytic activity was evaluated using methylene blue (MB) as a model pollutant.

Glycinium 3-carb-oxy-4-hy-droxy-benzene-sulfonate

In the anion of the title salt, C₂H₆NO₂⁺·C₇H₅O₆S⁻, the dihedral angle between the carb­oxy­lic acid group and the benzene ring is 5.02 (12)°. In the crystal, the anions are linked into inversion dimers through pairs of O—H⋯O hydrogen bonds between the carb­oxy­lic acid groups and sulfonate O atoms. A pair of C—H⋯O inter­actions is also observed within each dimer. The anion dimers and the cations are linked into a three-dimensional network by N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds.

Benzotriazolium 4-methyl-benzene-sulfonate

In the title molecular salt, C₆H₆N₃⁺·C₇H₇O₃S⁻, the components are linked by N—H⋯O hydrogen bonds into zigzag chains along [100]. These chains are further connected by weak C—H⋯O, C—H⋯π and π–π (centroid-to-centroid distances = 3.510, 3.701 and 3.754 Å) inter­actions into a three-dimensional network.

Synthesis, growth, structural, optical and thermal properties of an organic single crystal: 4-nitroaniline 4-aminobenzoic acid

The organic single crystals of 4-nitroaniline 4-aminobenzoic acid (4NAABA) were grown from ethanol solvent. The lattice parameters of the grown crystal have been confirmed from single crystal XRD analysis. The powder XRD pattern shows the various planes of grown crystal. The FTIR and (1)H NMR spectral analysis confirm the presence of various functional groups and the placement of proton in 4NAABA compound respectively. The UV absorption was carried out which shows the cutoff wavelength around 459 nm. The optical band gap of the crystal has been evaluated from the transmission spectra and absorption coefficient by extrapolation technique. In addition, a fluorescence spectral analysis is carried out for 4NAABA crystals. The thermal properties of crystals were evaluated from thermogravimetrical analysis. It shows that the grown crystal is stable up to 160°C and the crystal has sharp melting point at 151°C.

1H-Benzotriazole–4-hydroxybenzoic acid (1/1)

The asymmetric unit of the title compound, C₆H₅N₃·C₇H₆O₃, comprises independent benzotriazole and 4-hydroxybenzoic acid molecules. The dihedral angle between the benzene ring and the benzotriazole ring system is 15.18 (7)°. The mean plane of the carb­oxyl group is twisted at an angle of 18.55 (1)° with respect to the benzene ring. The crystal structure is stabilized by weak inter­molecular N—H⋯N, O—H⋯N, O—H⋯O and C—H⋯O inter­actions, forming a three-dimensional network.

Uronium 3-carboxy-4-hydroxybenzenesulfonate

In the title compound, CH₅N₂O⁺·C₇H₅O₆S⁻, the dihedral angle between the benzene ring and the mean plane of the uronium cation is 76.02 (8)°. The carboxyl group in the anion is twisted by 1.47 (9)° from the benzene ring. In the crystal, the cation is linked to the anion by weak O—H⋯O and N—H⋯O hydrogen bonds and π–π inter­actions [centroid–centroid distance = 3.8859 (8) Å], forming a three-dimensional network.

1-Methyl-4-(4-methylstyryl)pyridinium 4-methylbenzenesulfonate

In the title salt, C₁₅H₁₆N⁺·C₇H₇O₃S⁻, the dihedral angle between the pyridine and benzene rings of the cation is 5.98 (18)°. In the crystal, adjacent anions and cations are linked by weak non-classical C—H⋯O hydrogen bonds and π–π inter­actions, with a centroid–centroid distance of 3.749 (2) Å.