Cyanide Removal by ZnTiO/TiO/HO/UVB System: A Theoretical-Experimental Approach.

Cyanide is a highly toxic substance present in wastewater from various industries. This study investigates the removal of cyanide species (CS) from aqueous solutions using the ZnTiO/TiO/HO/UVB system. ZnTiO/TiO nanoparticles synthesized by the sol-gel method were characterized by powder X-ray diffractometry (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS).

Porous Geopolymer/ZnTiO/TiO Composite for Adsorption and Photocatalytic Degradation of Methylene Blue Dye.

In this study, GP (geopolymer) and GTA (geopolymer/ZnTiO/TiO) geopolymeric materials were prepared from metakaolin (MK) and characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), energy dispersive X-rays (EDX), specific surface area (SSA), and point of zero charge (PZC). The adsorption capacity and photocatalytic activity of the compounds prepared in the form of pellets was determined by degradation of the methylene blue (MB) dye in batch reactors, at pH = 7.0 ± 0.

Comparative Study of the Effect of Doping ZnTiO with Rare Earths (La and Ce) on the Adsorption and Photodegradation of Cyanide in Aqueous Systems.

Cyanide is a highly toxic compound that can pose serious health problems to both humans and aquatic organisms. Therefore, the present comparative study focuses on the removal of total cyanide from aqueous solutions by photocatalytic adsorption and degradation methods using ZnTiO (ZTO), La/ZnTiO (La/ZTO), and Ce/ZnTiO (Ce/ZTO). The nanoparticles were synthesized by the sol-gel method and characterized by X-ray powder diffractometry (XRD), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), Diffuse reflectance spectroscopy (DRS), and Specific surface area (SSA).

The Effect of La on the Methylene Blue Dye Removal Capacity of the La/ZnTiO Photocatalyst, a DFT Study.

Theoretically, lanthanum can bond with surface oxygens of ZnTiO to form La-O-Ti bonds, resulting in the change of both the band structure and the electron state of the surface. To verify this statement, DFT calculations were performed using a model with a dispersed lanthanum atom on the surface (101) of ZnTiO. The negative heat segmentation values obtained suggest that the incorporation of La on the surface of ZnTiO is thermodynamically stable.

Phonon-driven ultrafast exciton dissociation at donor-acceptor polymer heterojunctions.

A quantum-dynamical analysis of exciton dissociation at polymer heterojunctions is presented, using a hierarchical electron-phonon model parametrized for three electronic states and 28 vibrational modes. Two representative interfacial configurations are considered, both of which exhibit an ultrafast exciton decay. The efficiency of the process depends critically on the presence of intermediate bridge states, and on the dynamical interplay of high- vs low-frequency phonon modes.

Phonon-driven exciton dissociation at donor-acceptor polymer heterojunctions: direct versus bridge-mediated vibronic coupling pathways.

We present a molecular-level, quantum dynamical analysis of phonon-driven exciton dissociation at polymer heterojunctions, using a linear vibronic coupling model parametrized for 3 electronic states and 24 vibrational modes. Quantum dynamical simulations were carried out using the multiconfiguration time-dependent Hartree method. In this study, which significantly extends the two-state model of Tamura et al.

Excited state calculations on fluorene-based polymer blends: effect of stacking orientation and solvation.

Polyfluorene-based polymer blends have been utilized in the development of optoelectronic devices. The constituent copolymers are chemically designed to facilitate more efficient electron/hole mobility, thereby enhancing control over exciton formation and dissociation. When appropriate pairs of these are blended together, intermolecular charged-particle localizations are induced, leading to significant intermolecular charge-transfer character and luminescence that exhibit some sensitivity to their interfacial orientation.

Exciton regeneration dynamics in model donor-acceptor polymer heterojunctions.

We present a theoretical investigation on various semiconducting materials that exhibit photovoltaic and photoluminecent properties. Our focus is on the relaxation dynamics that occur upon photoexcitation of a couple of type II donor-acceptor heterojunction systems. In addition to the diabatic approach our two-band exciton model employs to study the phonon-assisted relaxations, we adopt the Marcus-Hush semiclassical method to incorporate lattice reorganization.

Exciton dissociation dynamics in model donor-acceptor polymer heterojunctions. I. Energetics and spectra.

In this paper we consider the essential electronic excited states in parallel chains of semiconducting polymers that are currently being explored for photovoltaic and light-emitting diode applications. In particular, we focus upon various type II donor-acceptor heterojunctions and explore the relation between the exciton binding energy to the band offset in determining the device characteristic of a particular type II heterojunction material. As a general rule, when the exciton binding energy is greater than the band offset at the heterojunction, the exciton will remain the lowest-energy excited state and the junction will make an efficient light-emitting diode.