Hemispherical shell-thin lamellar WS2 porous structures composited with CdS photocatalysts for enhanced H2 evolution
TL;DR: In this paper, hemispherical shell-thin lamellar Tungsten disulfide (WS2) porous structures have been designed to make use of synergistic effect between slow photo effect of WS2 pore and high electron transfer of 2D WS2 for promoting photocatalyst activity.
About: This article is published in Chemical Engineering Journal.The article was published on 2020-05-15. It has received 53 citations till now. The article focuses on the topics: Lamellar structure & Cadmium sulfide.
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TL;DR: In this article, the NiTiO3-CuI-GD ternary system was successfully constructed based on morphology modulation and energy band structure design, and the unique spatial arrangement of the composite catalyst was utilized to improve the hydrogen production activity under light.
Abstract: As the demand of fossil fuels continues to expand, hydrogen energy is considered a promising alternative energy. In this work, the NiTiO3-CuI-GD ternary system was successfully constructed based on morphology modulation and energy band structure design. First, the one-pot method was used to cleverly embed the cubes CuI in the stacked graphdiyne (GD) to prepare the hybrid CuI-GD, and CuI-GD was anchored on the surface of NiTiO3 by simple physical stirring. The unique spatial arrangement of the composite catalyst was utilized to improve the hydrogen production activity under light. Second, to combine various characterization tools and energy band structures, we proposed an step-scheme (S-scheme) heterojunction photocatalytic reaction mechanism, among them, the tubular NiTiO3 formed by the self-assembled of nanoparticles provided sufficient sites for the anchoring of CuI-GD, and the thin layer GD acted as an electron acceptor to capture a large number of electrons with the help of the conjugated carbon network; cubes CuI could consume holes in the reaction system; the loading of CuI-GD greatly improved the oxidation and reduction ability of the whole catalytic system. The S-scheme heterojunction accelerated the transfer of carriers and improved the separation efficiency. The experiment provides a new insight into the construction of an efficient and eco-friendly multicatalytic system.
63 citations
TL;DR: In this paper, a step-scheme heterojunction was constructed between two materials, and through this heterjunction, the spatial charge separation was boosted, which led to more useful electrons with a higher reduction ability that participated in a photocatalytic H2 evolution reaction.
54 citations
TL;DR: In this article, an excellent Z-scheme CdSe-Ag-WO3-Ag photocatalyst was constructed via continuous photo-assisted process, which exhibited superior photocatalytic activity in H2 evolution (448.31μmol•g−1 for 4h) with simultaneous degradation of CFZ (96.32% in just 30min).
50 citations
TL;DR: In this paper, an S-type heterojunction photocatalyst with high efficiency and low cost was proposed. But, it is still a great challenge to develop photocatalysts that can reach the scale of industrialization.
Abstract: It is still a great challenge to develop photocatalysts with high efficiency and low cost to reach the scale of industrialization. In this work, we prepared an S-type heterojunction photocatalyst w...
49 citations
01 Jan 2022
TL;DR: The construction of a tandem S-scheme heterojunction forms a built-in electric field at the interface between the catalysts and increases the photocatalytic reduction potential as mentioned in this paper .
Abstract: The construction of a tandem S-scheme heterojunction forms a built-in electric field at the interface between the catalysts and increases the photocatalytic reduction potential.
33 citations
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TL;DR: Mise au point comportant des definitions generales et la terminologie, la methodologie utilisee, les procedes experimentaux, les interpretations des donnees d'adsorption, les determinations de l'aire superficielle, and les donnes sur la mesoporosite et la microporosite.
Abstract: Mise au point comportant des definitions generales et la terminologie, la methodologie utilisee, les procedes experimentaux, les interpretations des donnees d'adsorption, les determinations de l'aire superficielle, et les donnees sur la mesoporosite et la microporosite
20,347 citations
TL;DR: Analyses indicate that the enhanced electrocatalytic activity of WS₂ is associated with the high concentration of the strained metallic 1T (octahedral) phase in the as-exfoliated nanosheets.
Abstract: Efficient evolution of hydrogen via electrocatalysis at low overpotentials is promising for clean energy production. Monolayered nanosheets of chemically exfoliated WS2 are shown to be efficient catalysts for hydrogen evolution at very low overpotentials. The enhanced catalytic performance is associated with the high concentration of the strained metallic octahedral phase in the exfoliated nanosheets.
2,249 citations
TL;DR: In this paper, the authors reported atomically thin nanosheets of chemically exfoliated 2H (trigonal prismatic) XS2 as efficient catalysts for hydrogen evolution with very low overpotentials.
Abstract: The ability to efficiently evolve hydrogen via electrocatalysis at low overpotentials holds tremendous promise for clean energy. Hydrogen evolution reaction (HER) can be easily achieved from water if a voltage above the thermodynamic potential of the HER is applied. Large overpotentials are energetically inefficient but can be lowered with expensive platinum based catalysts. Replacement of Pt with inexpensive, earth abundant electrocatalysts would be significantly beneficial for clean and efficient hydrogen evolution. Towards this end, promising HER characteristics have been reported using 2H (trigonal prismatic) XS2 (where X = Mo or W) nanoparticles with a high concentration of metallic edges as electrocatalysts. The key challenges for HER with XS2 are increasing the number and catalytic activity of active sites. Here we report atomically thin nanosheets of chemically exfoliated WS2 as efficient catalysts for hydrogen evolution with very low overpotentials. Atomic-resolution transmission electron microscopy and spectroscopy analyses indicate that enhanced electrocatalytic activity of WS2 is associated with high concentration of strained metallic 1T (octahedral) phase in the as-exfoliated nanosheets. Density functional theory calculations reveal that the presence of strain in the 1T phase leads to an enhancement of the density of states at the Fermi level and increases the catalytic activity of the WS2 nanosheet. Our results suggest that chemically exfoliated WS2 nanosheets could be interesting catalysts for hydrogen evolution.
1,712 citations
TL;DR: The development of synthetic protocols for producing colloidal WS2 monolayers, presenting not only the usual semiconducting prismatic 2H-WS2 structure but also the less common distorted octahedral 1T- WS2 structure, which exhibits metallic behavior.
Abstract: In recent years, a lot of attention has been devoted to monolayer materials, in particular to transition-metal dichalcogenides (TMDCs). While their growth on a substrate and their exfoliation are well developed, the colloidal synthesis of monolayers in solution remains challenging. This paper describes the development of synthetic protocols for producing colloidal WS2 monolayers, presenting not only the usual semiconducting prismatic 2H-WS2 structure but also the less common distorted octahedral 1T-WS2 structure, which exhibits metallic behavior. Modifications of the synthesis method allow for control over the crystal phase, enabling the formation of either 1T-WS2 or 2H-WS2 nanostructures. We study the factors influencing the formation of the two WS2 nanostructures, using X-ray diffraction, microscopy, and spectroscopy analytical tools to characterize them. Finally, we investigate the integration of these two WS2 nanostructured polymorphs into an efficient photocatalytic hydrogen evolution system to compa...
642 citations
TL;DR: Narrow-bandgap semiconductor WS2 nanosheets are active photocatalysts, either under visible or under NIR irradiation, via photogeneration of an electron-hole pair, with a low rate of recombination.
Abstract: Narrow-bandgap semiconductor WS2 nanosheets are active photocatalysts, either under visible or under NIR irradiation. The photocatalyst functions are confirmed via photogeneration of an electron-hole pair, with a low rate of recombination.
465 citations