42
4 Hydrogen Sulfide Decomposition and Nanotechnology
and this resulted in the deposition of the film onto the inner surface of the pipe. Six
layers were applied in the similar manner, and the pipe was dried for 5 min before the
application of the next layer. Afterward, the TiO 2 -coated quartz pipe was calcined
at 500 °C for 2 h. This quartz pipe coated with TiO 2 film was used as the photochemical reactor. The prepared films were analyzed in XRD, X-ray photoelectron
spectroscopy (XPS), and SEM. From the characterization, it was found that the TiO 2
film with mean crystalline size of 24 nm was formed [23].
Nilima et al. have developed nanostructures of N-doped TiO 2 in marigold-like
morphology with solvothermal process for H 2 generation from H 2 S. The N-doped
TiO 2 was prepared making the solution of titanium tetra-isopropoxide in methanol
followed by the addition of hydrazine hydrate. This resulted in the formation of white
precipitate indicating the formation of complex between Ti
4+ and hydrazine hydrate.
Later on, solution of guanidine carbonate in acetic acid was added in the mixture,
which dissolved the formed complex (white precipitates). The whole mixture was
then placed in the solution in sealed autoclave with Teflon lining at 150° C for 9–16 h.
The product thus obtained was washed and dried at 80
o C. The structural examination
of the prepared nanomaterials has shown that the Ti is present in anatase form in the
synthesized nanostructures. The N-doping in the nanostructures is confirmed by
photoluminescence and photoemission spectroscopy. The microscopic analysis has
shown that the thickness of petal in N–TiO 2 marigold-like nanostructures is around
∼2–3 nm. These nanostructures have been proven to be effective photocatalyst for
the dissociation of H 2 S for the generation of hydrogen under sunlight [24].
4.4 Zinc-Based Nanomaterials and Hydrogen Sulfide
Decomposition
Zinc-based photocatalysts are also involved in the decomposition of the H 2 S for
evolution of H 2 . Nanostructured ZnIn 2 S 4 has been found to be very active in the
photocatalytic decomposition of H 2 S for the production of sustainable hydrogen. In
an investigation, hydrothermal process was employed for the fabrication of ZnIn 2 S 4
nanoparticles. The said nanostructures were developed by placing the mixture of Zn
(NO 3 ) 2 .6H 2 O, In(NO 3 ) 3 .5H 2 O, and excessive thiourea and double distilled water in
stainless-steel autoclave lined with Teflon, along with double distilled water at 150 °C
for 30 h. Yellow precipitates were obtained as product. The obtained product was
given ethanol wash and was dried at 70 °C. The marigold morphology of the prepared
nanostructures was studied with FESEM, and it was found that the nanomaterials
have marigold-like morphology with the size of flower in the range of 3–5 µ m
and the thickness of the petal was ~ 3–5 nm. 5287 µ mol/h evolution of hydrogen
was achieved by utilizing these nanostructures via the decomposition of H 2 S under
visible light radiations. The chemical reaction for the evolution of hydrogen with the
said catalyst can be given as [25].
4 Hydrogen Sulfide Decomposition and Nanotechnology
and this resulted in the deposition of the film onto the inner surface of the pipe. Six
layers were applied in the similar manner, and the pipe was dried for 5 min before the
application of the next layer. Afterward, the TiO 2 -coated quartz pipe was calcined
at 500 °C for 2 h. This quartz pipe coated with TiO 2 film was used as the photochemical reactor. The prepared films were analyzed in XRD, X-ray photoelectron
spectroscopy (XPS), and SEM. From the characterization, it was found that the TiO 2
film with mean crystalline size of 24 nm was formed [23].
Nilima et al. have developed nanostructures of N-doped TiO 2 in marigold-like
morphology with solvothermal process for H 2 generation from H 2 S. The N-doped
TiO 2 was prepared making the solution of titanium tetra-isopropoxide in methanol
followed by the addition of hydrazine hydrate. This resulted in the formation of white
precipitate indicating the formation of complex between Ti
4+ and hydrazine hydrate.
Later on, solution of guanidine carbonate in acetic acid was added in the mixture,
which dissolved the formed complex (white precipitates). The whole mixture was
then placed in the solution in sealed autoclave with Teflon lining at 150° C for 9–16 h.
The product thus obtained was washed and dried at 80
o C. The structural examination
of the prepared nanomaterials has shown that the Ti is present in anatase form in the
synthesized nanostructures. The N-doping in the nanostructures is confirmed by
photoluminescence and photoemission spectroscopy. The microscopic analysis has
shown that the thickness of petal in N–TiO 2 marigold-like nanostructures is around
∼2–3 nm. These nanostructures have been proven to be effective photocatalyst for
the dissociation of H 2 S for the generation of hydrogen under sunlight [24].
4.4 Zinc-Based Nanomaterials and Hydrogen Sulfide
Decomposition
Zinc-based photocatalysts are also involved in the decomposition of the H 2 S for
evolution of H 2 . Nanostructured ZnIn 2 S 4 has been found to be very active in the
photocatalytic decomposition of H 2 S for the production of sustainable hydrogen. In
an investigation, hydrothermal process was employed for the fabrication of ZnIn 2 S 4
nanoparticles. The said nanostructures were developed by placing the mixture of Zn
(NO 3 ) 2 .6H 2 O, In(NO 3 ) 3 .5H 2 O, and excessive thiourea and double distilled water in
stainless-steel autoclave lined with Teflon, along with double distilled water at 150 °C
for 30 h. Yellow precipitates were obtained as product. The obtained product was
given ethanol wash and was dried at 70 °C. The marigold morphology of the prepared
nanostructures was studied with FESEM, and it was found that the nanomaterials
have marigold-like morphology with the size of flower in the range of 3–5 µ m
and the thickness of the petal was ~ 3–5 nm. 5287 µ mol/h evolution of hydrogen
was achieved by utilizing these nanostructures via the decomposition of H 2 S under
visible light radiations. The chemical reaction for the evolution of hydrogen with the
said catalyst can be given as [25].