40
4 Hydrogen Sulfide Decomposition and Nanotechnology
matrix were prepared by using cadmium iodide and PPS. The mixture of the two
compounds was heated at 285 °C (melting point of PPS) in a Pt crucible for 48 h.
The product thus obtained was analyzed with X-ray diffractions (XRD), transmission electron microscopy (TEM), and field-emission scanning electron microscope
(FESEM). The characterization of the product showed that the CdS nanocrystallites
of 6 to 28 nm in size were restrained on PPS matrix. 19.7% quantum yield of H 2
production was achieved with the prepared nanomaterials [17].
Yao et al. have reported a facile method for the production of Pd–Cr 2 O 3 /CdS
nanocomposite to be used as a photocatalyst for the generation of H 2 from H 2 S.
For the preparation of the nanocomposites, the aqueous solution of H 2 PdCl 4 and Cr
(NO 3 ) 3 . nH 2 O was allowed to react with NaBH 4 . The accumulation of the nanoparticles during H 2 PdCl 4 reduction was prevented by the addition of polyvinylpyrolidone
(PVP) in the solution with thorough mixing. Afterward, CdS was added to the solution
with vigorous stirring resulting in the formation of Pd–Cr 2 O 3 /CdS nanocomposite.
A quantum yield of H 2 increased from 37.3% to 55.6% at 420 nm by optimizing
chromium oxide loading of CdS in nanocomposite catalyst. The prepared catalysts
depicted better photocatalytic ability as compared to the pristine Pd. This can be associated to the presence of interface for charge transfer. No characterization analysis
of the prepared composites was reported in the study [18].
Nanostructure of spinel semiconductors of varying morphologies has huge significant applications as photocatalyst. A group of investigators synthesized a cubic
spinel chemically stable nanostructure of CdIn 2 S 4 via simple hydrothermal process
as visible light active photocatalyst for the generation of hydrogen by decomposing
H 2 S. For the preparation of these nanostructures, mixture of Cd (NO 3 ) 2 · 4H 2 O,
In(NO 3 ) 3 · 3H 2 O, and excessive thiourea was placed in stainless-steel autoclave lined
with teflon along with double distilled water at 140 °C for 60 h. The product was
obtained in form of yellow precipitates. The obtained product was given ethanol
wash and was dried at 70 °C. The marigold morphology was shown by the samples
in aqueous medium whereas nanotubes with 25 nm diameter were formed in organic
solvent (methanol) under similar conditions. Different characterization techniques
like XRD, TEM, and FESEM were used for the analysis of the prepared nanostructures. The nanocatalyst exhibited excellent photocatalytic activity in both mediums.
The CdIn 2 S 4 nanostructures showed give hydrogen quantum yields of 17.1% with
nanotube morphology whereas 16.8% with marigold-like morphology in visible
light. The promising ability of the catalyst for the generation of hydrogen is directly
associated to the high crystallinity of the prepared catalyst [19].
A quantum dot-glass nanosystem of CdS 0.5 Se 0 and CdSe was prepared and used
for the hydrogen production from hydrogen sulfide by Sanjay et al. The synthesized
nonensemble was grown on germanate glass matrix via facile melt quench technique.
The glass used for the preparation of the nanosystem consists of GeO 2 , Na 2 O K 2 O,
ZnO, TiO 2 , and B 2 O 3 .Al 2 O 3 . The CdSe and CdS 0.5 Se 0 5 were used as dopants on
the glass surface. The nanosystem was prepared by making the adequately homogenized mixture of host glass powder and the dopant CdS0.5Se0.5/CdSe. Electrical
furnace was used for melting of the mixture at 900–950 °C for 2 h. Later on, the
product was quenched and annealed at 425 °C in an adjustable furnace. Afterward,
4 Hydrogen Sulfide Decomposition and Nanotechnology
matrix were prepared by using cadmium iodide and PPS. The mixture of the two
compounds was heated at 285 °C (melting point of PPS) in a Pt crucible for 48 h.
The product thus obtained was analyzed with X-ray diffractions (XRD), transmission electron microscopy (TEM), and field-emission scanning electron microscope
(FESEM). The characterization of the product showed that the CdS nanocrystallites
of 6 to 28 nm in size were restrained on PPS matrix. 19.7% quantum yield of H 2
production was achieved with the prepared nanomaterials [17].
Yao et al. have reported a facile method for the production of Pd–Cr 2 O 3 /CdS
nanocomposite to be used as a photocatalyst for the generation of H 2 from H 2 S.
For the preparation of the nanocomposites, the aqueous solution of H 2 PdCl 4 and Cr
(NO 3 ) 3 . nH 2 O was allowed to react with NaBH 4 . The accumulation of the nanoparticles during H 2 PdCl 4 reduction was prevented by the addition of polyvinylpyrolidone
(PVP) in the solution with thorough mixing. Afterward, CdS was added to the solution
with vigorous stirring resulting in the formation of Pd–Cr 2 O 3 /CdS nanocomposite.
A quantum yield of H 2 increased from 37.3% to 55.6% at 420 nm by optimizing
chromium oxide loading of CdS in nanocomposite catalyst. The prepared catalysts
depicted better photocatalytic ability as compared to the pristine Pd. This can be associated to the presence of interface for charge transfer. No characterization analysis
of the prepared composites was reported in the study [18].
Nanostructure of spinel semiconductors of varying morphologies has huge significant applications as photocatalyst. A group of investigators synthesized a cubic
spinel chemically stable nanostructure of CdIn 2 S 4 via simple hydrothermal process
as visible light active photocatalyst for the generation of hydrogen by decomposing
H 2 S. For the preparation of these nanostructures, mixture of Cd (NO 3 ) 2 · 4H 2 O,
In(NO 3 ) 3 · 3H 2 O, and excessive thiourea was placed in stainless-steel autoclave lined
with teflon along with double distilled water at 140 °C for 60 h. The product was
obtained in form of yellow precipitates. The obtained product was given ethanol
wash and was dried at 70 °C. The marigold morphology was shown by the samples
in aqueous medium whereas nanotubes with 25 nm diameter were formed in organic
solvent (methanol) under similar conditions. Different characterization techniques
like XRD, TEM, and FESEM were used for the analysis of the prepared nanostructures. The nanocatalyst exhibited excellent photocatalytic activity in both mediums.
The CdIn 2 S 4 nanostructures showed give hydrogen quantum yields of 17.1% with
nanotube morphology whereas 16.8% with marigold-like morphology in visible
light. The promising ability of the catalyst for the generation of hydrogen is directly
associated to the high crystallinity of the prepared catalyst [19].
A quantum dot-glass nanosystem of CdS 0.5 Se 0 and CdSe was prepared and used
for the hydrogen production from hydrogen sulfide by Sanjay et al. The synthesized
nonensemble was grown on germanate glass matrix via facile melt quench technique.
The glass used for the preparation of the nanosystem consists of GeO 2 , Na 2 O K 2 O,
ZnO, TiO 2 , and B 2 O 3 .Al 2 O 3 . The CdSe and CdS 0.5 Se 0 5 were used as dopants on
the glass surface. The nanosystem was prepared by making the adequately homogenized mixture of host glass powder and the dopant CdS0.5Se0.5/CdSe. Electrical
furnace was used for melting of the mixture at 900–950 °C for 2 h. Later on, the
product was quenched and annealed at 425 °C in an adjustable furnace. Afterward,