FULL PAPER 1700472 (1 of 6) Significant Enhancement of Hydrogen Production in MoS 2 /Cu 2 ZnSnS 4 Nanoparticles (original) (raw)
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Zn2x(CuIn)1−xS2 photocatalysts synthesis by a hydrothermal process using H4EDTA as complexing agent
International Journal of Hydrogen Energy, 2012
The study of the Zn 2x (CuIn) 1Àx S 2 (0 x 1) solid solutions formation by hydrothermal synthesis using ethylenediaminetetraacetic acid (H 4 EDTA) as a complexant and surfactant agent is reported for the first time. Different synthesis parameters were varied: the H 4 EDTA concentration, the initial pH value, the Tu concentration, the duration and temperature of autoclaving process. The as obtained powders were characterized by Xray powder diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and UV/vis/NIR diffuse reflection spectroscopy (DRS). The XRD and EDX results show that, with a careful adjustment of the reaction conditions, especially of the H 4 EDTA concentration and initial pH value of the precursor solution, a mixture of solid solutions with sphalerite type structure can be obtained, which transforms into a single phase solid solution after heat treatment. The particles, as revealed by SEM investigations, have nanoporous hexagonal microplates morphology, about 1 mm thick and several microns in diameter. The Cu 0.159 In 0.111 Zn 1.778 S 2 photocatalyst obtained by this method presents photocatalytic activity for hydrogen evolution from aqueous solutions containing S 2À ions as sacrificial agent, even without cocatalyst.
Catalysis Today, 2019
Photocatalytic production of hydrogen has been investigated over irradiated aqueous dispersions of mixed Cd-Zn sulfide catalysts (CZS) promoted with nickel or nickel phosphide in the presence of sulfide/sulfite ions as sacrificial electron donors. The CZS composites were prepared by a co-precipitation method followed by calcination in air at temperatures in the range of 300 to 600 o C. It has been found that heat treatment at 500 o C results in materials with increased activity for H2 evolution, which is attributed to the formation of the Zn0.78Cd0.22S phase. Photocatalytic performance of CZS(500) is further improved following addition of small amounts of Ni or Ni2P on the photocatalyst surface. The activity of the optimized materials, loaded with 0.05 wt.% Ni or 0.25 wt.% Ni2P, exhibit similar activity with a Pt-promoted CZS(500) catalyst, and is one order of magnitude higher than that of the reference TiO2 catalyst of the same platinum loading (0.25 wt.% Pt). Results of long-term stability tests show that the 0.25%Ni2P/CZS(500) catalyst is very stable in the presence of S 2-/SO3 2ions in solution, with cadmium leaching not exceeding 0.1% after 65 h under irradiation. Experiments performed with the use of low (or negative) cost waste materials, such as real wastewater resulting from film printing processes or glycerol solutions, demonstrate that the 0.25%Ni2P/CZS(500) photocatalyst exhibits stable H2 evolution even in the absence of S 2-/SO3 2ions and has the potential to be used as a solar light-responsive photocatalyst for practical applications.
2020
Transition metal dichalcogenides (TMDs) are promising materials for photocatalytic functions. In class of TMDs, MoS 2 is comprehensively explored as a co-catalyst due to the extraordinary activity for photocatalytic activity of organic dye degradation. But the catalytic activities of MoS 2 are generated through S ions on depiction edges. Also numerous of S ions existed on basal planes are catalytically inactive. The insertion of external metals in MoS 2 organism is extensive way for activation of basal planes surface to enhance concentration of catalytically active sites. For this purpose, nanoparticles of Nickel (Ni) doped MoS 2 are prepared by hydrothermal technique. Structural and morphological analysis are characterized by XRD and SEM, respectively. XRD results showed that Ni is completely doped into MoS 2. SEM showed that pure MoS 2 has sheet like structure and Ni doped MoS 2 has mix disc and flower like structure. Band gap energy was observed in declining range of 2.30-1.76 eV. The photocatalytic activity of pure MoS 2 and Ni doped MoS 2 were evaluated by degrading MB and RhB dyes under UV light irradiation. MB dye degradation of MB was 71% for pure MoS 2. For 1% to 5% Ni doping in MoS 2 , MB dye degradated from 85% to 96%. It means that MB dye degradation of MB was enhanced continuously by increasing the concentration of Ni doping. RhB dye degradation of RhB was 62% for pure MoS 2. For 1% to 5% Ni doping in MoS 2 , the RhB dye degradated from 77% to 91%.
Zn2(CuIn)1−S2 photocatalysts synthesis by a hydrothermal process using H4EDTA as complexing agent
International Journal of Hydrogen Energy, 2012
The study of the Zn 2x (CuIn) 1Àx S 2 (0 x 1) solid solutions formation by hydrothermal synthesis using ethylenediaminetetraacetic acid (H 4 EDTA) as a complexant and surfactant agent is reported for the first time. Different synthesis parameters were varied: the H 4 EDTA concentration, the initial pH value, the Tu concentration, the duration and temperature of autoclaving process. The as obtained powders were characterized by Xray powder diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and UV/vis/NIR diffuse reflection spectroscopy (DRS). The XRD and EDX results show that, with a careful adjustment of the reaction conditions, especially of the H 4 EDTA concentration and initial pH value of the precursor solution, a mixture of solid solutions with sphalerite type structure can be obtained, which transforms into a single phase solid solution after heat treatment. The particles, as revealed by SEM investigations, have nanoporous hexagonal microplates morphology, about 1 mm thick and several microns in diameter. The Cu 0.159 In 0.111 Zn 1.778 S 2 photocatalyst obtained by this method presents photocatalytic activity for hydrogen evolution from aqueous solutions containing S 2À ions as sacrificial agent, even without cocatalyst.
Materials Science in Semiconductor Processing, 2021
The present article reports the hydrothermal synthesis of quaternary Cu 2 MnSnS 4 (CMTS) nanostructures under subcritical reaction conditions. The effect of different chalcogen (sulfur) precursor sources (L-cysteine, elemental sulfur and sodium sulfide) on the growth and properties of the nanostructures is studied. The sulfur precursors showed prominent influence on the structural and morphological properties of the nanostructures. Structural properties indicated the growth of single phase crystalline materials. The crystal phase was controlled and determined by the reactivity of the sulfur sources. Metastable wurtzite phase was achieved with the mildly reactive precursor while tetragonal phase was obtained in the case of highly reactive precursors. Morphological studies showed formation of nanoflakes and anisotropic two-dimensional irregular nanostructures. Surface area analysis indicated that the nanoflakes are mesoporous in nature and exhibited a high specific surface area of 32.24 m 2 /g. The electrical studies demonstrated p-type conductivity of the material. Optical properties revealed optimum energy band gap value (~1.7 eV) of the nanostructures, suitable for the solar energy conversion applications. The magnetic properties indicated ferromagnetic behavior of the CMTS nanoflakes. The nanostructures were investigated as catalysts for photocatalytic decolaration of malachite green (MG) dye under UV-Visible light illumination. The nanoflakes showed good activity against the dye and photodegraded 95% of the dye in an illumination duration of 140 min. The photocatalysts exhibited good stability during the photocatalytic processes.