Efficient conversion of solar energy into useful chemical fuels is a major scientific challenge. Water-splitting dyesensitized photoelectrochemical cells (WS-DSPECs) utilize mesoporous oxide supports sensitized with molecular dyes and catalysts to drive the water-splitting reaction. Despite a growing body of work, the overall efficiencies of WS-DSPECs remain low, in large part because of poor e...

In this work we report the application of a recently developed experimental protocol using Pulsed Field Gradient (PFG) Nuclear Magnetic Resonance (NMR) techniques to simultaneously assess bulk pore and surface diffusion coefficients in liquid saturated porous catalysts. This method has been developed to study solvent effects on the diffusion of methyl ethyl ketone (MEK) in mesoporous 1 wt% Pd/A...

Numerical simulation and experimental investigation were used for study of laminar forced convective heat transfer of Al2O3/water nanofluid. Single phase model with temperaturedependent properties was employed for numerical simulation of transport phenomena in nanofluid. The results of experiments and computer-aided simulation indicated remarkable enhancement of convective heat transfer of base...

Hydrogen is an important chemical in many industries and it is expected to become one of the major fuels for energy generation in the future. Unfortunately, hydrogen does not exist in its elemental form in nature and therefore has to be produced from hydrocarbons, hydrogen-containing compounds or water. Above its critical point (374.8C and 22.1MPa), water has lower density and viscosity, and a ...

We report on a thickness-dependent wetting property of WS2/Al2O3 and WS2/SiO2/Si structures. We prepared WS2 films with gradient thickness by annealing thickness-controlled WO3 films at 800 °C in sulfur atmosphere. Raman spectroscopy measurements showed step-like variation in the thickness of WS2 over substrates several centimeters in dimension. On fresh surfaces, we observed a significant chan...

The dephasing dynamics of a vibrational coherence may reveal the interactions of chemical functional groups with their environment. To investigate this process at a surface, we employ free induction decay sum frequency generation (FID-SFG) to measure the time that it takes for free OH stretch oscillators at the charged (pH ≈ 13, KOH) interface of alumina/water (Al2O3/H2O) to lose their collecti...

In this paper a new equation for calculating the nanofluid viscosity by considering the Brownian motion of nanoparticles is introduced. The relative velocity between the base fluid and nanoparticles has been taken into account. This equation presents the nanofluid viscosity as a function of the temperature, the mean nanoparticle diameter, the nanoparticle volume fraction, the nanoparticle densi...

alumina-supported cs3[re(c2o4)3] precursor has been synthesized  for preparation of re-cs/g-al2o3 catalyst. cs3[re(c2o4)3]  has been prepared from the reaction of recl3 with  h2c2o4.2h2o and cscl in water. the complex has been characterized by elemental analysis and various spectroscopy techniques such as ft-ir, uv-vis and 13c-nmr. the complex was supported on γ-al2o3 by column chromatography. ...

for better understanding the effect of nanofluid flow in a porous medium, a set of experiments were conducted on a horizontal glass micromodel for al2o3-water nanofluids. to characterize the flow of nanofluids the same experiment was done by pure water. the glass micromodel was constructed by a photolithography technique. the al2o3-water nanofluids were produced by a two-step method and no surf...