44
4 Hydrogen Sulfide Decomposition and Nanotechnology
the nanostructures was in the range of ∼4–5 nm. The nanostructure showed ∼3957
µ mol/h rate of hydrogen evolution [27]. The chemical reaction for the evolution of
hydrogen with p-type N-doped ZnO from H 2 S can be given as.
H 2 S + OH
−
↔ SH
−
+ H 2 O.
N − ZnO → h
+
+ e
−
h
+
= valence band hole; e
−
= conduction band electron
.
2SH
−
+ 2h
+
→ 2S
2−
+ 2H
+
(oxidation reaction).
2H
+
+ 2e
−
→ H 2
(reduction reaction).
4.5 Other Nanomaterials and Hydrogen Sulfide
Decomposition
In an investigation, hierarchical nanostructure-like dandelion flowers and nanorods
of Bi 2 S 3 were developed by solvothermal process. The Bi 2 S 3 nanomaterials were
developed making the solution of Bi (NO) 3 · 5H 2 O and thiourea in a mixture of water
and ethylene glycol and were stirred for 1 h. The whole mixture was then placed in
stainless-steel autoclave lined with Teflon at 150 °C. After the completion of the reaction, the system was allowed to cool at room temperature. Black precipitates were
obtained in the form of product which were washed with water and ethanol at 80 °C.
FESEM, XRD, and TEM analysis were used for the characterization of the synthesized nanomaterials. The prepared nanomaterials were utilized for the photocatalytic
decomposition of H 2 S for H 2 generation under visible light. The prepared Bi 2 S 3 hierarchical nanostructure depicted remarkable hydrogen generation of 8.88 mmol/g/h
under daylight (between 11.30 am and 2.30 pm on bright sunny day) whereas the
nanorods generated 7.08 mmol/g/h of hydrogen under similar conditions from the
decomposition of H 2 S. This can be associated to the fact that the hierarchical nanostructure has multiple surface defects which improve the separation of the charge
carriers [28].
In another study, CuGaO 2 and its indium-doped analogue CuGa 1−0.065 In 0.065 O 2
delafossite oxides co-catalysts nanostructures were fabricated and utilized for the
generation of hydrogen from H 2 S. The nanocatalysts were prepared via solid-state
process. XRD analysis of the materials depicted that they have hexagonal rhombohedral structure. The morphological analysis with FESEM of the nanocatalysts
indicated that CuGaO 2 has deformed plate-like particles while CuGa 1−0.065 In 0.065 O 2
have systematic hexagonal rod-like arrangements. The prepared catalysts were able
to decompose hydrogen sulfide in aqueous KOH solution in visible light radiations.
At the incident radiation of λ = 550 nm, quantum yield of 13.6% for hydrogen
4 Hydrogen Sulfide Decomposition and Nanotechnology
the nanostructures was in the range of ∼4–5 nm. The nanostructure showed ∼3957
µ mol/h rate of hydrogen evolution [27]. The chemical reaction for the evolution of
hydrogen with p-type N-doped ZnO from H 2 S can be given as.
H 2 S + OH
−
↔ SH
−
+ H 2 O.
N − ZnO → h
+
+ e
−
h
+
= valence band hole; e
−
= conduction band electron
.
2SH
−
+ 2h
+
→ 2S
2−
+ 2H
+
(oxidation reaction).
2H
+
+ 2e
−
→ H 2
(reduction reaction).
4.5 Other Nanomaterials and Hydrogen Sulfide
Decomposition
In an investigation, hierarchical nanostructure-like dandelion flowers and nanorods
of Bi 2 S 3 were developed by solvothermal process. The Bi 2 S 3 nanomaterials were
developed making the solution of Bi (NO) 3 · 5H 2 O and thiourea in a mixture of water
and ethylene glycol and were stirred for 1 h. The whole mixture was then placed in
stainless-steel autoclave lined with Teflon at 150 °C. After the completion of the reaction, the system was allowed to cool at room temperature. Black precipitates were
obtained in the form of product which were washed with water and ethanol at 80 °C.
FESEM, XRD, and TEM analysis were used for the characterization of the synthesized nanomaterials. The prepared nanomaterials were utilized for the photocatalytic
decomposition of H 2 S for H 2 generation under visible light. The prepared Bi 2 S 3 hierarchical nanostructure depicted remarkable hydrogen generation of 8.88 mmol/g/h
under daylight (between 11.30 am and 2.30 pm on bright sunny day) whereas the
nanorods generated 7.08 mmol/g/h of hydrogen under similar conditions from the
decomposition of H 2 S. This can be associated to the fact that the hierarchical nanostructure has multiple surface defects which improve the separation of the charge
carriers [28].
In another study, CuGaO 2 and its indium-doped analogue CuGa 1−0.065 In 0.065 O 2
delafossite oxides co-catalysts nanostructures were fabricated and utilized for the
generation of hydrogen from H 2 S. The nanocatalysts were prepared via solid-state
process. XRD analysis of the materials depicted that they have hexagonal rhombohedral structure. The morphological analysis with FESEM of the nanocatalysts
indicated that CuGaO 2 has deformed plate-like particles while CuGa 1−0.065 In 0.065 O 2
have systematic hexagonal rod-like arrangements. The prepared catalysts were able
to decompose hydrogen sulfide in aqueous KOH solution in visible light radiations.
At the incident radiation of λ = 550 nm, quantum yield of 13.6% for hydrogen