Strategies to Enhance ZnO Photocatalyst's Performance for Water Treatment: A Comprehensive Review.

Despite the photocatalytic organic pollutant degradation using ZnO started in 1910-1911, many challenges are still ahead, and several critical issues have to be addressed. Large band gap, and short life-time of photogenerated electrons and holes are critical issues negatively affect the photocatalytic activity of ZnO. Various approaches have been introduced to overcome these issues including intrinsic doping, extrinsic doping, and heterostructure. This review introduces unique and deep insights into tuning of the photocatalytic activity of ZnO. It starts by description of how to tune the photocatalytic activity of pristine ZnO through tuning its morphology, surface area, exposed face, and intrinsic defects. Afterward, the review explains how the Z-scheme approach succeed to address the redox weakened issue of heterojunction approach. In general, this review provides a clear image that helps the researcher to tune the photocatalytic activity of pristine ZnO and its heterostructure.

Effect of nucleants in photothermally assisted crystallization.

Laser-induced crystallization is emerging as a promising technique to crystallize biomolecules like amino acids and proteins. The use of external materials as nucleants and novel seeding methods open new paths for protein crystallization. We report here the results of experiments that explore the effect of nucleants on laser-based crystallization of microlitre droplets of small molecules, amino acids, and proteins. The role of parameters like solute concentration, droplet volume, type and size of the nucleant, and laser power, are systematically investigated. In addition to crystallization of standard molecules like NaCl, KCl, and glycine, we demonstrate the crystallization of negatively (l-histidine), and positively (l-aspartic acid) charged amino acids and lysozyme protein. Single crystal X-ray diffraction and Raman spectroscopy studies unequivocally indicate that the nucleants do not alter the molecular structure of glycine, hydrogen bonding patterns, and packing. Localized vaporization of the solvent near the nucleant due to photothermal heating has enabled us to achieve rapid crystallization - within 3 s - at laser intensities of 0.1 MW cm-2, significantly lower than those reported earlier, with both saturated and unsaturated solutions. The outcome of the current experiments may be of utility in tackling various crystallization problems during the formation of crystals large enough to perform X-ray crystallography.

Synthesis, anticancer, structural, and computational docking studies of 3-benzylchroman-4-one derivatives.

A series of 3-Benzylchroman-4-ones were synthesized and screened for anticancer activity by MTT assay. The compounds were evaluated against two cancerous cell lines BT549 (human breast carcinoma), HeLa (human cervical carcinoma), and one noncancerous cell line vero (normal kidney epithelial cells). 3b was found to be the most active molecule against BT549 cells (IC50 = 20.1 µM) and 3h against HeLa cells (IC50 = 20.45 µM). 3b also exhibited moderate activity against HeLa cells (IC50 = 42.8 µM). The molecular structures of 3h and 3i were solved by single crystal X-ray crystallographic technique. Additionally, the molecular docking studies between the tumour suppressor protein p53 with the lead compound 3h, which exhibited better anticancer activity against HeLa cells was examined.

Mineralogy of agricultural soil of selected regions of South Western Karnataka, Peninsular India.

Agricultural soils of selected regions of Southwestern Karnataka, Peninsular India, were subjected to systematic mineralogical characterization along with the study of soil physical properties. Physical properties such as soil texture and micro porosity were studied using particle size analyses and positron annihilation lifetime analysis (PALS) technique, respectively. The latter was used to analyze micro porosity of agricultural soil. Both major and minor minerals were identified and confirmed by some analytical techniques like thin section study, powder X-ray diffraction, X-ray fluorescence spectroscopy and Fourier transform infrared spectroscopy.

Hydrothermal fabrication of selectively doped organic assisted advanced ZnO nanomaterial for solar driven photocatalysis.

Hydrothermal fabrication of selectively doped (Ag(+)+Pd(3+)) advanced ZnO nanomaterial has been carried out under mild pressure temperature conditions (autogeneous; 150°C). Gluconic acid has been used as a surface modifier to effectively control the particle size and morphology of these ZnO nanoparticles. The experimental parameters were tuned to achieve optimum conditions for the synthesis of selectively doped ZnO nanomaterials with an experimental duration of 4 hr. These selectively doped ZnO nanoparticles were characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy and scanning electron microscopy (SEM). The solar driven photocatalytic studies have been carried out for organic dyes, i.e., Procion MX-5B dye, Cibacron Brilliant Yellow dye, Indigo Carmine dye, separately and all three mixed, by using gluconic acid modified selectively doped advanced ZnO nanomaterial. The influence of catalyst, its concentration and initial dye concentration resulted in the photocatalytic efficiency of 89% under daylight.

N-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-di-hydro-1H-pyrazol-4-yl)-2-(4-nitro-phen-yl)acetamide.

In the title compound, C19H18N4O4, the nitro-phenyl and phenyl rings are twisted by 67.0 (6) and 37.4 (4)°, respectively, with respect to the pyrazole ring plane [maximum deviation = 0.0042 (16) Å]. The dihedral angle between the mean planes of the phenyl rings is 59.3 (3)°. The amide group, with a C-N-C-C torsion angle of 177.54 (13)°, is twisted away from the plane of the pyrazole ring in an anti-periplanar conformation. In the crystal, N-H⋯O hydrogen bonds involving the carbonyl group on the pyrazole ring and the amide group, together with weak C-H⋯O inter-actions forming R 2 (2)(10) graph-set motifs, link the mol-ecules into chains along [100]. Additional weak C-H⋯O inter-actions involving the nitro-phenyl rings further link the mol-ecules along [001], also forming R 2 (2)(10) graph-set motifs, thereby generating (010) layers.

Crystal structure of N-[3-(2-chloro-benzo-yl)-5-ethyl-thio-phen-2-yl]-2-[(E)-(2-hy-droxy-benzyl-idene)amino]-acetamide.

In the title compound, C22H19ClN2O3S, the dihedral angle between the mean planes of the thio-phene ring and the chloro-phenyl and hy-droxy-phenyl rings are 70.1 (1) and 40.2 (4)°, respectively. The benzene rings are twisted with respect to each other by 88.9 (3)°. The imine bond lies in an E conformation. Intra-molecular O-H⋯N and N-H⋯O hydrogen bonds each generate S(6) ring motifs. In the crystal, weak C-H⋯O inter-actions link the mol-ecules, forming chains along the c axis and zigzag chains along the b axis, generating sheets lying parallel to (100).

Crystal structure of N-(3-benzoyl-4,5,6,7-tetra-hydro-1-benzo-thio-phen-2-yl)benzamide.

In the title compound, C22H19NO2S, the cyclo-hexene ring adopts a half-chair conformation. The dihedral angles between the plane of the thio-phene ring and those of its amide- and carbonyl-bonded benzene rings are 7.1 (1) and 59.0 (2)°, respectively. An intra-molecular N-H⋯O hydrogen bond generates an S(6) ring. In the crystal, very weak aromatic π-π stacking inter-actions [centroid-centroid separation = 3.9009 (10) Å] are observed.

[2-(Benzyl-idene-amino)-4,5,6,7-tetra-hydro-benzo[b]thio-phen-3-yl](phen-yl)methanone.

In the title compound, C22H19NOS, the cyclo-hexene ring of the tetra-hydro-benzo-thio-phenyl ring system adopts a slightly distorted half-chair conformation and is twisted slightly [7.5 (8)° for the major disorder component] from the mean plane of the thio-phene ring. The dihedral angles between the mean planes of the thio-phene ring and the phenyl rings are 65.7 (3) and 8.3 (4)°. The phenyl rings are twisted with respect to each other by 73.8 (7)°. Disorder was modeled for four C atoms of the cyclo-hexene ring over two sets of sites with an occupancy ratio of 0.659 (2):0.341 (2). In the crystal, a single weak C-H⋯O inter-action links the mol-ecules into [001] chains.

{2-[(2-Bromo-5-meth-oxy-benzyl-idene)amino]-4,5,6,7-tetra-hydro-benzo[b]thiophen-3-yl}(phen-yl)methanone.

In the title compound, C23H20BrNO2S, disorder was modeled for the outer two C atoms of the cyclo-hexene ring over two sets of sites with an occupancy ratio of 0.580 (11):0.420 (11). Both rings have a half-chair conformation. The dihedral angles between the mean plane of the thio-phene ring and the benzene and phenyl rings are 9.2 (2) and 66.1 (2)°, respectively. The benzene and phenyl rings are inclined to each other by 74.8 (8)°. In the crystal, mol-ecules are linked by pairs of C-H⋯O hydrogen bonds, forming inversion dimers.

{2-[(4-Nitro-benzyl-idene)amino]-4,5,6,7-tetrahydro-1-benzo-thio-phen-3-yl}(phen-yl)methanone.

In the title compound, C22H18N2O3S, disorder is found in the benzoyl group (A and B), as well as for four C atoms of the cyclo-hexene ring. Two orientations were modeled in a 0.583 (5):0.417 (5) ratio. The cyclo-hexene ring is in a distorted chair conformation. The dihedral angles between the mean plane of the thio-phene ring and the 4-nitro-benzene and phenyl rings are 30.9 (8) and 64.8 (3) (A) and 62.4 (7)° (B). The mean planes of the 4-nitro-benzene and the phenyl rings are almost perpendicular to each other, with dihedral angles of 85.4 (1) (A) and 83.9 (8)° (B). An extensive array of weak C-H⋯O inter-actions consolidate mol-ecules into a three-dimensional architecture, forming chains along [001] and [010] and layers parallel to (011).

{2-[(2-Hy-droxy-benzyl-idene)amino]-4,5,6,7-tetra-hydro-1-benzo-thio-phen-3-yl}(phen-yl)methanone.

In the title compound, C22H19NO2S, the cyclo-hexene ring adopts a slightly distorted half-chair conformation. The dihedral angles between the mean planes of the thio-phene ring and the phenyl and 2-hy-droxy-phenyl rings are 70.4 (5) and 12.1 (9)°, respectively. The phenyl and 2-hy-droxy-phenyl rings are twisted with respect to one another by 81.0 (6)°. A short intra-molecular O-H⋯N hydrogen bond is observed. In the crystal, weak C-H⋯O inter-actions link the mol-ecules into zigzag chains diagonally along [100] .

{2-[(1H-Indol-3-yl-methyl-idene)amino]-4,5,6,7-tetra-hydro-benzo[b]thio-phen-3-yl}(phen-yl)methanone.

The title compound, C24H20N2OS, crystallizes with two independent mol-ecules (A and B) in the asymmetric unit, in each of which the cyclo-hexene rings adopt half-chair conformations. The mean plane of the indole ring is twisted from those of the phenyl and thio-phene rings by 69.0 (7) and 8.3 (5)°, respectively, in mol-ecule A and by 65.4 (9) and 6.7 (5)°, respectively, in mol-ecule B. The dihedral angles between the mean planes of the phenyl and thio-phene rings are 63.0 (4) and 58.8 (9)° in mol-ecules A and B, respectively. In the crystal, N-H⋯O hydrogen bonds lead to the formation of an infinite chain along [101]. In addition, π-π stacking inter-actions are observed involving the thio-phene and pyrrole rings of the two mol-ecules, with a shortest inter-centroid distance of 3.468 (2) Å.

Desvenlafaxinium chloranilate ethyl acetate solvate.

In the cation of the title compound, C16H26NO2 (+)·C6HCl2O4 (-)·C4H8O2, the 1-hy-droxy-cyclo-hexyl ring adopts a slightly distorted chair conformation. The dihedral angle between the mean planes of the 1-hy-droxy-cyclo-hexyl and 4-hy-droxy-phenyl rings is 84.0 (8)°. In the anion, the hydroxyl H atom is twisted slightly out of the ring plane with a C-C-O-H torsion angle of -171.9°. Disorder was modeled for the methyl group of the acetate group in the solvate with an occupancy ratio of 0.583 (15): 0.417 (15). In the crystal, O-H⋯O hydrogen bonds are observed between cations and between cations and anions, while bifuricated N-H⋯(O,O) cation-anion hydrogen bonds are also present, forming chains along [010] and [100]. In addition weak cation-anion and cation-solvate C-H⋯O inter-actions occur.

Ceria Boosting on In Situ Nitrogen-Doped Graphene Oxide for Efficient Bifunctional ORR/OER Activity.

In the present work, a highly efficient and excellent electrocatalyst material for bifunctional oxygen reduction/evolution reaction (ORR/OER) was synthesized using the microwave-assisted hydrothermal method. In brief, ultrafine hexagonal cerium oxide (CeO2) nanoparticles were tailored on the layered surface of in situ nitrogen-doped graphene oxide (NGO) sheets. The nanocomposites exhibited a high anodic onset potential of 0.925 V vs. RHE for ORR activity and 1.2 V for OER activity with a very high current density in 0.5 M KOH. The influence of oxygen cluster on Ce3+/Ce4+ ion decoration on outward/inward in situ nitrogen-coupled GO enhanced the physicochemical properties of composites and in turn increased electron transferability. The microwave-assisted hydrothermal coupling technique provides a higher density, active sites on CeO2@NGO composites, and oxygen deficiency structures in ultrafine Ce-O particles and boosts higher charge transferability in the composites. It is believed that the physical states of Ce-N- C, Ce-C=O, and a higher amount of oxygen participation with ceria increase the density of composites that in turn increases the efficiency. N-doped graphene oxide promotes high current conduction and rapid electron transferability while reducing the external transport resistance in oxygen electrocatalysis by sufficient mass transfer through in-built channels. This study may provide insights into the knowledge of Ce-enabled bifunctional activity to guide the design of a robust catalyst for electrochemical performance.

Venom peptides - A comprehensive translational perspective in pain management.

Venom peptides have been evolving complex therapeutic interventions that potently and selectively modulate a range of targets such as ion channels, receptors, and signaling pathways of physiological processes making it potential therapeutic. Several venom peptides were deduced in vivo for clinical development targeting pain management, diabetes, cardiovascular diseases, antimicrobial activity. Several contributions have been detailed for a clear perspective for a better understanding of venomous animals, their venom, and their pharmacological effects. Here we unravel and summarize the recent advances in wide venom peptides across varieties of species for their therapeutics prospects.

In situ surface modification of molybdenum-doped organic-inorganic hybrid TiO2 nanoparticles under hydrothermal conditions and treatment of pharmaceutical effluent.

Molybdenum-doped TiO2 organic-inorganic hybrid nanoparticles were synthesized under mild hydrothermal conditions by in situ surface modification using n-butylamine. This was carried out at 150 degrees C at autogeneous pressure over 18 h. n-Butylamine was selected as a surfactant since it produced nanoparticles of the desired size and shape. The products were characterized using powder X-ray diffraction, Fourier transform infrared spectrometry, dynamic light-scattering spectroscopy, UV-Vis spectroscopy and transmission electron microscopy. Chemical oxygen demand was estimated in order to determine the photodegradation efficiency of the molybdenum-doped TiO2 hybrid nanoparticles in the treatment of pharmaceutical effluents. It was found that molybdenum-doped TiO2 hybrid nanoparticles showed higher photocatalytic efficiency than untreated TiO2 nanoparticles.

Polymer-wrapped single-walled carbon nanotubes: a transformation toward better applications in healthcare.

Carbon nanotubes (CNTs) possess outstanding properties that could be useful in several technological, drug delivery, and diagnostic applications. However, their unique physical and chemical properties are hindered due to their poor solubility. This article review's the different ways and means of solubility enhancement of single-wall carbon nanotubes (SWNTs). The advantages of SWNTs over the multi-walled carbon nanotubes (MWNTs) and the method of non-covalent modification for solubility enhancement has been the key interest in this review. The review also highlights a few examples of dispersant design. The review includes some interesting utility of SWNTs being wrapped with polymer especially in biological media that could mediate proper drug delivery to target cells. Further, the use of wrapped SWNTs with phospholipids, nucleic acid, and amphiphillic polymers as biosensors is of research interest. The review aims at summarizing the developments relating to wrapped SWNTs to generate further research prospects in healthcare.

Nanoparticles synthesis using supercritical fluid technology - towards biomedical applications.

Supercritical fluid (SCF) technology has become an important tool of materials processing in the last two decades. Supercritical CO(2) and H(2)O are extensively being used in the preparation of a great variety of nanomaterials. The greatest requirement in the application of nanomaterials is its size and morphology control, which determine the application potential of the nanoparticles, as their properties vary significantly with size. Although significance of SCF technology has been described earlier by various authors, the importance of this technology for the fabrication of inorganic and hybrid nanomaterials in biomedical applications has not been discussed thoroughly. This review presents the nanomaterial preparation systematically using SCF technology with reference to the processing of biomedical materials. The basic principles of each one of the processes have been described in detail giving their merits and perspectives. The actual experimental data and results have been discussed in detail with respect to the selected nanomaterials for biomedical applications. The SCF synthesis of nanoparticles like phosphors, magnetic materials, carbon nanotubes, etc. have been discussed as they have potential applications in bio-imaging, hyperthermia, cancer therapy, neutron capture therapy, targeted drug delivery systems and so on. The more recent approach towards the in situ surface modification, dispersibility, single nanocrystal formation, and morphology control of the nanoparticles has been discussed in detail.

Direct Z-Scheme Cs2O-Bi2O3-ZnO Heterostructures as Efficient Sunlight-Driven Photocatalysts.

Limited light absorption, inefficient electron-hole separation, and unsuitable positions of conduction band bottom and/or valence band top are three major critical issues associated with high-efficiency photocatalytic water treatment. An attempt has been carried out here to address these issues through the synthesis of direct Z-scheme Cs2O-Bi2O3-ZnO heterostructures via a facile, fast, and economic method: solution combustions synthesis. The photocatalytic performances are examined by the 4-chlorophenol degradation test under simulated sunlight irradiation. UV-vis diffuse reflectance spectroscopy analysis, electrochemical impedance test, and the observed transient photocurrent responses prove not only the significant role of Cs2O in extending light absorption to visible and near-infrared regions but also its involvement in charge carrier separation. Radical-trapping experiments verify the direct Z-scheme approach followed by the charge carriers in heterostructured Cs2O-Bi2O3-ZnO photocatalysts. The Z-scheme charge carrier pathway induced by the presence of Cs2O has emerged as the reason behind the efficient charge carrier separation and high photocatalytic activity.