Band-gap-matched CdSe QD/WS 2 nanosheet composite: Size-controlled photocatalyst for high-efficiency water splitting

Zhong, Yueyao; Shao, Yongliang; Ma, Fukun; Wu, Yongzhong; Huang, Baibiao; Hao, Xiaopeng

doi:10.1016/j.nanoen.2016.11.011

Cited by 112 publications

(51 citation statements)

References 24 publications

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“…Similarly, the binding energies for Cd 3d in Figure e were found to be 405.8 and 411.8 eV for the CdSe QDs and 405.9 and 412 eV for the CdSe QDs/WS 2 NF hybrids. This slight shift in binding energy indicates the successful growth of the CdSe QDs/WS 2 NF hybrids according to a previous reported Additionally, Figure f reveals a binding energy shift for Se 3d from 54.3 to 55.2 eV, similar to that for Cd 3d. The small peak intensities of Se 3d in both compounds indicate low amount of Se.…”

Section: Resultsmentioning

confidence: 99%

“…A summary of the current densities and Tafel slopes at 0 V is provided in Table S1, Supporting Information. As previously reported, this phenomenon is related to the bandgap energy and specific surface area required for reaction . As the size of the QDs increases, the WS 2 NFs are covered by large particles, which lower their contribution to HER performance, as indicated by the higher Tafel slopes and lower current densities at 0 V. As discussed in the experimental section, to the find the optimal amount of CdSe QDs in the WS 2 NFs, different concentrations ratio (5, 10, and 20%) of CdSe QDs were added to WS 2 NF solutions, followed by ultra‐sonication.…”

Section: Resultsmentioning

confidence: 99%

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CdSe Quantum Dots Doped WS₂ Nanoflowers for Enhanced Solar Hydrogen Production

Tekalgne

Hasani

et al. 2019

Physica Status Solidi (a)

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In this paper, a facile method for synthesizing WS2 nanoflowers (NFs) and CdSe quantum dots (QDs) using hydrothermal and hot injection methods, are reported, respectively. Additionally, the photocatalytic activity of a CdSe QDs/WS2 NF nanocomposite is analyzed in a typical three‐electrode electrochemical cell. It is found that the CdSe QDs/WS2 NF hybrid exhibits a current density of −1.12 mA at 0 V and a Tafel slope of 82 mV dec−1, which are superior to the values of bare WS2 NFs (current density of −0.25 mA and Tafel slope of 150 mV dec−1). This improvement of photocatalytic performance is attributed to the wide range of light absorption for e−/h+ generation provided by the CdSe QDs, as well as the large surface area and numerous active sites for hydrogen production provided by WS2 NFs. Therefore, the CdSe QDs/WS2 NF hybrid structure is a promising candidate for highly effective and stable photocatalytic performance under solar light illumination for hydrogen production.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

CdSe Quantum Dots Doped WS₂ Nanoflowers for Enhanced Solar Hydrogen Production

Tekalgne

Hasani

et al. 2019

Physica Status Solidi (a)

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“…The lower photocatalytic H 2 production in 0.7Ni-Si/MgO nanorods could be a consequence of poor intralayer charge transport. Further, the drastic enhancement of photocatalytic activity for ultra-thin nanosheets is attributed to the following factors: 17,63,64 i) The holey 2D ultrathin structure of 0.5Ni-Si/ MgO nanosheets can provide more exposed new catalytic active sites which maximizes the cross-plane diffusion of photogenerated carriers; ii) Short migration path of ultrathin nanosheets for photogenerated electron may results in high activity; iii) a dense network of crystalline nanosheets may decrease the electron diffusion length and provides enhanced photon absorption to the catalyst; (iv) the randomly branched nanosheets may increase light-harvesting efficiency by scattering enhancement and trapping. As is well-known, the photocatalytic activity is closely related to photoexcited electrons-hole generation.…”

Section: Resultsmentioning

confidence: 99%

Ultrathin Assembles of Porous Array for Enhanced H2 Evolution

Islam¹,

Teo

Awual

et al. 2020

Sci Rep

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Since the complexity of photocatalyst synthesis process and high cost of noble cocatalyst leftovers a major hurdle to producing hydrogen (H 2 ) from water, a noble metal-free Ni-Si/MgO photocatalyst was realized for the first time to generate H 2 effectively under illumination with visible light. The catalyst was produced by means of simple one-pot solid reaction using self-designed metal reactor. The physiochemical properties of photocatalyst were identified by XRD, FESEM, HRTEM, EDX, UVvisible, XPS, GC and PL. The photocatalytic activities of Ni-Si/MgO photocatalyst at different nickel concentrations were evaluated without adjusting pH, applied voltage, sacrificial agent or electron donor. The ultrathin-nanosheet with hierarchically porous structure of catalyst was found to exhibit higher photocatalytic H 2 production than hexagonal nanorods structured catalyst, which suggests that the randomly branched nanosheets are more active surface to increase the light-harvesting efficiency due to its short electron diffusion path. The catalyst exhibited remarkable performance reaching up to 714 µmolh −1 which is higher among the predominant semiconductor catalyst. The results demonstrated that the photocatalytic reaction irradiated under visible light illumination through the production of hydrogen and hydroxyl radicals on metals. The outcome indicates an important step forward one-pot facile approach to prepare noble ultrathin photocatalyst for hydrogen production from water.Why do we need to promote hydrogen energy? The scientist lays out about four main reasons-energy-saving, minimal ecological impacts, energy security and industrial competitiveness. Industrially, fossil-fuel based hydrogen production process emits greenhouse gas to the environment 1 . The use of solar energy to produce hydrogen from water could accelerate the development of high-impact breakthrough clean energy technologies. By developing an optimal photocatalyst, scientists are searching for the ways of improving clean energy (H 2 ) production from water without producing greenhouse gases or having many adverse effects on the atmosphere.A variety of titanium dioxide (TiO 2 ) phases and nanostructures have been studied extensively for photocatalytic hydrogen production because of its earth-abundance, non-toxicity as well as thermal and chemical stability 1,2 . However, photoirradiated electron recombination and wide band gap of bare TiO 2 remain challenge on efficient hydrogen production. Much work has been directed towards the adaptation of noble Pd, Au metals on the TiO 2 metals 3-5 or through the use of sacrificial reagents 6 . Noble co-catalyst could serve as electron sinks to isolate the photogenerated electron-holes 3 . Moreover, noble metals assist to boost the reaction process by lowering over-potential for proton deduction 4 . Unfortunately, the state-of-the-art co-catalysts are still noble metals (e.g. Pt, Au, Pd) or their oxides that are rare and expensive. As a consequence, the discovery of robust, low-cost and earth-abundant co-catalyst...

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“…The CdSe shell layer was stimulated to produce the photoinduced electrons and holes by visible light. Because the conduction band (CB) of CdSe nanoparticles ( E CB = −0.93 eV) is more negative than that of TiO 2 nanorods ( E CB = −0.5 eV), suggesting a typical type II band alignment formed between CdSe and TiO 2 , the photogenerated electrons on CB of CdSe can be quickly transferred to CB of TiO 2 . Meanwhile, the holes on valence band (VB) of CdSe can react with the sacrificial agent (Na 2 S), and the electrons are transferred to Pt counter electrode to perform the hydrogen evolution reaction.…”

Section: Resultsmentioning

confidence: 99%

Construction of CdSe@TiO ₂ core‐shell nanorod arrays by electrochemical deposition for efficient visible light photoelectrochemical performance

Zhuang

Liu

et al. 2019

Int J Energy Res

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Summary The CdSe@TiO2 core‐shell nanorod arrays for photoelectrochemical (PEC) application were designed and constructed by a facile electrochemical deposition strategy. The CdSe@TiO2 photoanodes exhibit highly efficient PEC performance under visible light irradiation, among which the CdSe shell layer thickness can be precisely adjusted by different electrodeposition time. In comparison with nude TiO2 nanorods, the optimized CdSe@TiO2 photoanode (TC‐500) shows a significant saturated photocurrent density of 2.1 mA/cm2 at 0 V (vs Ag/AgCl), which is attributed to the good distribution of CdSe nanoparticles on TiO2 nanorod arrays, the favorable band alignment, and the intimate interfacial interaction between CdSe nanoparticles and TiO2 nanorods. The introduction of CdSe shell layer does not only improve light absorption ability but also enhances photogenerated charge carrier's transfer and separation. This current work systematically studies the accurate adjustment of CdSe shell layer thickness on TiO2 nanorod arrays by electrochemical deposition strategy and provides a paradigm to design and fabricate heterostructure composite for PEC application.

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Band-gap-matched CdSe QD/WS 2 nanosheet composite: Size-controlled photocatalyst for high-efficiency water splitting

Cited by 112 publications

References 24 publications

CdSe Quantum Dots Doped WS₂ Nanoflowers for Enhanced Solar Hydrogen Production

CdSe Quantum Dots Doped WS₂ Nanoflowers for Enhanced Solar Hydrogen Production

Ultrathin Assembles of Porous Array for Enhanced H2 Evolution

Construction of CdSe@TiO ₂ core‐shell nanorod arrays by electrochemical deposition for efficient visible light photoelectrochemical performance

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Band-gap-matched CdSe QD/WS 2 nanosheet composite: Size-controlled photocatalyst for high-efficiency water splitting

Cited by 112 publications

References 24 publications

CdSe Quantum Dots Doped WS2 Nanoflowers for Enhanced Solar Hydrogen Production

CdSe Quantum Dots Doped WS2 Nanoflowers for Enhanced Solar Hydrogen Production

Ultrathin Assembles of Porous Array for Enhanced H2 Evolution

Construction of CdSe@TiO 2 core‐shell nanorod arrays by electrochemical deposition for efficient visible light photoelectrochemical performance

Contact Info

Product

Resources

About

CdSe Quantum Dots Doped WS₂ Nanoflowers for Enhanced Solar Hydrogen Production

CdSe Quantum Dots Doped WS₂ Nanoflowers for Enhanced Solar Hydrogen Production

Construction of CdSe@TiO ₂ core‐shell nanorod arrays by electrochemical deposition for efficient visible light photoelectrochemical performance