2 research outputs found
Solubility and Chemical Thermodynamics of d,l-Alanine and d,l-Serine in Aqueous NaCl and KCl Solutions
The solubilities of d,l-alanine
and d,l-serine
in aqueous sodium chloride (NaCl) and potassium chloride (KCl) solutions
are determined at five equidistant temperatures by using “formol
titrimetry”. The thermodynamic parameters such as standard
transfer Gibbs energies, entropies, and enthalpies have been evaluated
at 298.15 K. Other important related parameters like molar mass, density,
molar volume, dipole moment, and solvent diameter, etc., of the experimental
solutions are also determined in the present study. Δ<i>G</i><sub>t,ch</sub><sup>0</sup>(<i>i</i>), i.e., chemical effects of the transfer Gibbs
energies, and <i>T</i>Δ<i>S</i><sub>t,ch</sub><sup>0</sup>(<i>i</i>), i.e., chemical effects of the transfer entropy of these amino
acids, are also evaluated and discussed, the factors which are dependent
on mainly nature of the solute, solvent, interactions between solute
and solvent, etc. The nature and the extent of the involved factors,
which are influencing the solvation of the amino acids in aqueous
NaCl and KCl solutions, are also explained by the different physical
and analytical approaches
Development of Sustainable Catalyst Coating of Ni<sub>2</sub>P Engineered SrTiO<sub>3</sub> Nanocubes for Hydrogen Generation
Ni2P has a significant
importance in the field
of photocatalytic
water splitting, irrespective of its narrow band gap (1.0 eV). The
photocatalytic performance of bare Ni2P is highly limited
due to the fast recombination rate of the electron–hole pairs.
However, it can be used suitably for tuning the band gap of wide band
gap semiconductors. The present study involves the development of
an effective heterojunction with tuned band gap by Ni2P
engineered SrTiO3 nanocubes in the form of a coating after
successful compositional tuning. This is accomplished by an in situ decoration of SrTiO3 nanocubes at the
active sites of Ni2P via a chemical reduction method. Morphological
and physical features of the developed catalyst are tuned in the coating
in order to have Ni2P as the major phase for maintaining
the physical structure and to impart enhancement in photocatalytic
performance and stability to the catalyst system. As the conduction
band of SrTiO3 lies at a more negative potential compared
to that of Ni2P, the excited electrons from SrTiO3 can easily be injected to the active sites of Ni2P for
proton reduction. Thus, in addition to tuning the composite energy
band gap, Ni2P acts as the reaction center for hydrogen
generation and as the stable catalyst bed for SrTiO3 nanocube
decoration. The appearance of SrTiO3 enriches the electron
density at the Ni2P active sites, and Ni2P with
negatively charged phosphorus has the ability to capture more protons
at these sites for accelerating the rate of hydrogen generation. The
enhancement in the microsurface properties of Ni2P in the
composite coating are evaluated with OSP technique. The hydrogen generation
rate as high as 7.03 mmol/g/h is achieved with the as-engineered catalyst
coating, with an apparent quantum yield of 23.72% at 400 nm. The catalyst
system shows a sustained hydrogen generation rate even after 15 cycles
confirming the suitability of large scale production for industrial
applications