The effect of TiO2 nanotube morphological engineering and ZnS quantum dots on the water splitting reaction: A theoretical and experimental study

Abstract

a b s t r a c t Ordered arrays of TiO 2 nanotubes with smooth and rippled morphologies were prepared by one-step titanium oxidation in NH 4 F and ethylene glycol solution. The samples were then decorated with ZnS using a microwave-assisted solvothermal method. The experiments under constant or pulsed applied voltage resulted in smooth and rippled TiO 2 material morphologies, respectively. Field emission scanning electron microscopy, incident photonto-current efficiency, linear sweep voltammetry and electrochemical impedance spectroscopy were used to investigate the structure and morphology of the TiO 2 nanotubes, along with their photoelectrochemical activity in the water splitting reaction. An envelope function was proposed to correlate the anisotropic morphologies and broad distribution of mobility due to the random nature of charge carrier transport. The smooth and rippled morphologies were evaluated using the transmission line model. First-principles quantum mechanical calculations based on the density functional theory at the B3LYP level are conducted to obtain a better understanding of optical properties of TiO 2 .

Reading at exposed surfaces: theoretical insights into photocatalytic activity of ZnWO4

“…Photocatalysis is an appealing approach toward tackling environmental and global energy problems. Over the past decade, semiconductor photocatalysts with tailored morphologies have attracted intense research interest in many research fields, such as the photocatalytic degradation of pollutants 51 , water splitting [52][53][54] , and photocatalytic antibacterial fields 55,56 , owing to their many intrinsic shape-dependent properties 57,58 . Additionally, the exposed surfaces appearing on the morphology do not only determine the intrinsic physical and chemical properties, but also provide new technological applications in catalysis, optics, electronics, and magnetics.…”

Influence of Fe-Doping on the Structural and Electronic Properties of the TiO2 Anatase:Rutile

“…Band gap can be modified according to the lattice constant, composition, and morphology. Pereira et al 19 studied the effect of TiO 2 nanotube morphology with deposited ZnS nanoparticles through a theoretical and experimental approach. The Rietveld refinement showed that it is possible to deposit ZnS along the TiO 2 nanotube, and band structure calculations showed a decrease in the band gap values.…”

Hibiscus sabdariffa L. Anthocyanins Immobilization on TiO2 Nanotubes and Its Electrochemical Characterization as a Hydrogen Peroxide Sensing Electrode

“…It has received attention for its potential applications in sensing, solar cells, catalysis, electronics, optics and biomedicine. 14 Titanium dioxide nanotubes can be combined with other materials such as other metal oxides [15][16][17] noble metal nanoparticles 18,19 quantum dots 20,21 and carbon nanomaterials 22 to offer improved properties for its variety of applications. Besides, this nanostructure is characterized by their effective electron transfer behavior and highly adsorptive property for organic compounds z E-mail: monica.cerro@udlap.mx due to their abundant adsorption sites.…”