Green Synthesis of Surfactant Capped CTAB@Ag Nanoparticles and Study of Its Catalytic Activity

In the present study, ginger extract, which is widely available as a medicinal herb, is used to develop a facile method for green synthesis of bare Ag and surfactant capped CTAB@Ag nanoparticles via Hydrothermal route. The as-prepared Ag nanoparticles were characterized by UV-Vis spectroscopy, photoluminescence (PL), X-ray Diffraction (XRD), Infrared spectroscopy (IR), and Scanning electron microscopy (SEM). The catalytic properties of as prepared bare and surfactant capped CTAB@Ag nanoparticles were also investigated in reductive degradation of Methyl Orange (MO) dye and 4-Nitrophenol (4-NP). Surfactant-capped CTAB@Ag nanoparticles exhibit superior catalytic properties in the degradation of MO and conversion of 4-nitro phenol to 4-amino phenol when compared to bare silver nanoparticles.

Synergistic Excited State involved Catalytic Reduction of (NH3-trz)[Fe(dipic)2] Complex by SnO2/TiO2 Nanocomposite

The photocatalytic activity of well-fabricated, economical SnO2/TiO2 nanocomposite synthesized via hydrothermal route was validated using the (NH3-trz)[Fe(dipic)2] complex under ultra-violet illumination. The structural features of (NH3-trz)[Fe(dipic)2] complex was explored in detail. The catalysts were systematically examined with XRD, SEM, FT-IR UV-vis, PL, micro-Raman, VSM, AFM, HRTEM. The photoreactivity of the model compound (NH3-trz)[Fe(dipic)2] in water/binary solvent systems was investigated. The rate of photoreaction (k) of nanocomposite (0.1432 sec-1) is higher than the SnO2 (0.0373 sec-1) and TiO2 (0.1422 sec-1) in H2O:PriOH (70:30%) than the rest of the solvents system. The pathways, mechanistic feature of accumulated reactive species on nanocomposite to induce adherent [Fe(dipic)2]- anion and photo-reductive products were studied. The generation of hydroxyl radical on the surface of each catalyst can be identified as 7-hydroxycoumarin and discussed.

Fabrication of 3D hierarchical Fe2O3/SnO2 photoanode for enhanced photoelectrochemical performance

Exploring and fabricating a suitable photoanode with high catalytic activity is critical for enhancing photoelectrochemical (PEC) performance. Herein, a novel 3D hierarchical Fe2O3/SnO2 photoanode was fabricated by a hydrothermal route, combining with an annealing process. The morphology, crystal structure were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photon spectroscopy (XPS), and X-ray diffraction (XRD), respectively. The results reveal the successful preparation of Fe2O3 nanothorns on the surface of SnO2 nanosheets. The as-fabricated 3D Fe2O3/SnO2 photoanode yields obviously promoted PEC performance with a photocurrent density of approximate 5.85 mA cm-2, measured in a mixture of Na2S (0.25 M) and Na2SO3 (0.35 M) aqueous solution at 1.23 V (vs. reversible hydrogen electrode, RHE). This value of photocurrent is about 53 times higher than that of the bare SnO2 photoanode. The obvious improved PEC properties can be attributed to the 3D Fe2O3/SnO2 heterostructures that offer outstanding light harvesting ability as well as improved charge transport and separation. These results suggest that exploring a suitable 3D hierarchical photoanode is an effective approach to boost PEC performance.approach to boost PEC performance.

Hydrothermally synthesized nanocrystalline photoactive SnS2 thin films: Effect of surface directing agent

In the present work, we have synthesized tin disulphide (SnS2) thin films by facile, low cost, single-step hydrothermal route using various surface directing agents. The SnS2 thin films were characterized...

Electroluminescence and Photocatalytic Hydrogen Evolution of S,N Co-doped Graphene Oxide Quantum Dots

A facile hydrothermal route to synthesize S,N co-doped graphene oxide quantum dots (S,N-GOQDs) with stable electroluminescence, photoluminescence, and photocatalytic properties was demonstrated. The synthesized S,N-GOQDs show high yield and excitation–independent...

A rapid in-situ electrochemical transformation of biphase Zn3(OH)2V2O7∙2H2O/NH4V4O10 composite for high capacity and long cycling life aqueous rechargeable zinc ion batteries

2D Zn3(OH)2V2O7∙2H2O/NH4V4O10 nanobelts are synthesized by a simple hydrothermal route. It is the first report that the Zn3(OH)2V2O7∙2H2O/NH4V4O10 (ZnVO/NVO) nanobelts transform into Zn3(OH)2V2O7∙2H2O-based materials by an in-situ electrochemical conversion, which...

Photocatalytic Performance of Ta2O5/BiVO4 Heterojunction for Hydrogen Production and Methylene Blue Photodegradation

Forming semiconductor heterojunction is promising for improved photocatalytic performance due to synergistic combination of the best properties of each material. The present study reports a simple hydrothermal strategy to form n-n heterojunction of Ta2O5 nanotubes and BiVO4 microstructures. The Ta2O5/BiVO4 heterojunctions were characterized by Raman spectroscopy, UV‑Vis diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and their photocatalytic activity was evaluated by hydrogen production and photodegradation of methylene blue (MB) dye in aqueous medium under AM 1.5 G (100 mW cm‑2) condition. The heterojunctions have optical absorption in the visible region (200‑500 nm) with crystal structures defined as monoclinic for BiVO4 and orthogonal for Ta2O5. For MB photodegradation, the Ta2O5/BiVO4 obtained via hydrothermal route showed a photodegradation of 72.3%, compared to 28.3% presented by the sample produced through the mechanical mixture, with the maintenance of 86.4% of its photocatalytic performance after 3 cycles of photodegradation. For H2 production, hydrothermally prepared Ta2O5/BiVO4 generated 10.2 μmol g-1 of H2 in 3 h; while Ta2O5 nanotubes and mechanical Ta2O5/BiVO4 mixture shows 6.82 and 2.80 μmol g-1, respectively. The results suggest that Ta2O5/BiVO4 is a promising material for applications in photocatalysis, promoting sustainable energy production through hydrogen and for the treatment of effluents containing cationic dyes.

Enhanced Photocatalytic Performance in Chromium(VI) Reduction and Dye Degradation using Sn3O4/SnS2 Nanocomposite and Mechanism Insight

Detection of residual organic and inorganic species in water bodies including drinking water has led to developing strategies for their removal. Here we report a very efficient method of photoreduction of Cr (VI) and photodegradation of methylene blue dye in aqueous medium using Z-scheme heterojunction based Sn3O4/SnS2 solar photocatalyst. The photocatalyst is synthesized by hydrothermal route and it is thoroughly characterized in terms of its structural, compositional, morphological and optical properties. About 100 % of Cr (VI) reduction in 60 min and 99.6 % of methylene blue degradation in 90 min is achieve under sunlight exposure at a photocatalytic rate of 0.066 min-1 and 0.043 min-1, respectively. The total organic carbon estimation of the post-degradation reaction medium corresponded to 85.1 % (MB) mineralization. The photocatalytic degradation is attributed to in-situ generation of reactive oxygen species (ROS) e.g., superoxide radicals, hydroxide radicals, and the role of ROS towards reduction and degradation of Cr (VI) and MB respectively, is confirmed from ROS scavenging studies. The dye degradation mechanism has been discussed by analyzing the degradation products via UPLC-Q-Tof-MS. The photocatalytic degradation of methylene blue by Sn3O4/SnS2 nanocomposites is significantly enhanced as compared to SnS2 photocatalyst, attributed to Z-scheme heterojunction and the charge carrier mobility.

Hydrothermal synthesis of ABi2Ta2O9Aurivillius phase: A comparative study of A-site cation size on structure, dielectric, optical properties

In this study, the double-layered Aurivillius phases CaBi2Ta2O9 (CBT) and PbBi2Ta2O9 (PBT) were prepared through a hydrothermal route with NaOH as a mineralizer. XRD analysis confirmed that the CBT and PBT compounds were successfully formed and adopted an orthorhombic crystal structure with an [Formula: see text]21am symmetry. Le Bail refinements of XRD data indicated that the unit cell volume of CBT was smaller than PBT and is associated with the smaller ionic radius of Ca[Formula: see text] compared to Pb[Formula: see text]. The surface morphology of both samples, as determined using SEM, demonstrated plate-like grains with anisotropic grain growth. It was found that the different ionic radii of [Formula: see text]-site cations (Ca[Formula: see text] and Pb[Formula: see text] strongly affected the structural, optical and electrical properties of the Aurivillius phase. The occupation of smaller Ca[Formula: see text] cations induced a higher structural distortion, which resulted in higher bandgap ([Formula: see text] energy and ferroelectric transition temperature ([Formula: see text] of CBT, compared to those of PBT.