MnPSe₃ Monolayer: A Promising 2D Visible‐Light Photohydrolytic Catalyst with High Carrier Mobility

Advanced Science, Journal Year: 2016, Volume and Issue: 3(10)

Published: April 23, 2016

The 2D material single-layer MnPSe3 would be a promising photocatalyst for water splitting, as indicated by the proper positions of band edges, strong absorption in visible-light spectrum, broad applicability (pH = 0 – 7), and high carrier mobility. Since experimental realization graphene,1 materials have been receiving significant attention due to their unique physical chemical properties which mainly arise from topological effects surface-bulk ratios. Graphene has predominated most widely studied material. Intractably, lack gap limits its practical applications speed switching devices, photocatalysts, etc.2 Nevertheless, successful preparation graphene prompted researchers investigate more such hexagonal BN,3 transition metal dichalcogenides (TMDs),4 silicene,5 germanane,[5],6 phosphorene,7 MXene.8 These attract intensive interest novel electronic, mechanical or photocatalytic behaviors,9 making up shortages expanding field-effect transistors (FETs)10 photocatalysts.11 Recently, new kind (exemplified MnPSe3) was proposed Li et al.12 Then, series MPS3 (M Fe, Mn, Ni, Cd, Zn) MPSe3 Mn) were explored Du al.13 Particularly, bulk crystals few-layer samples MPX3 (X S, Se) obtained characterized experiments. previous reports that gaps these bulks range 1.3 3.5 eV,13 suggesting light at wide wavelength photocatalysts. Hydrogen generation splitting present method solar energy conversion play very important role solving serious environmental problems.14 However, inability utilize visible light, low quantum yield, fast backward reaction limit application splitting.15 with an appropriate (i.e., ≈2–3 eV) exhibit efficient use process. Moreover, nature means short distance generated electrons holes migrate, reducing possibility electron–hole recombination, then giving yields. Enlightened some are predicted photocatalysts under light,[15],16 especially proved good experiments g-C3N4,17 we investigated edges optical monolayers screen splitting. Then mobility calculated through deformation potential (DP) theory monolayer is direct-band-gap semiconductor region. (up 625.9 cm2 V−1 S−1) could comparable even higher than those many other materials, indicating transfer carriers reactive sites easier Our results disclose light. structural first. To determine ground state Mn), both spin-unpolarized spin-­polarized computations performed. show spin-polarized total energies less favorable spin-­unpolarized ones FePS3, CdPS3, ZnPS3, FePSe3 mono­layers, nonmagnetic states. MnPS3, NiPS3, mono­layers prefer antiferromagnetic (AFM) coupling, stable ferromagnetic (FM) state. structures kinds similar, shown Figure 1a. check stability monolayers, phonon spectra along high-symmetry points Brillouin zone computed, S1 (Supporting Information). There no imaginary modes reveals dynamically configurations realized Another issue confirm whether it can form freestanding monolayer. Therefore, in-plane stiffness should enough withstand own weight external load without substrates. this, , where Etotal, ε, S0 represent per unit cell, uniaxial strain, area optimized respectively. S2 Table Supporting Information. sulfides corresponding selenides, might result greater electronegativity sulfur. Through elasticity theory, estimate typical out-of-plane h/l ≈ (ρgl/C2D)1/3,18 l length monolayer, ρ density, g gravitational acceleration. Assuming 100 μm, ratio vertical Information, indicates sufficient rigidity exfoliation checked calculating cleavage energy. relative increases separation converges ideal gradually. lattice constants consistent data credibility calculations. As 1b, (0.29–0.54 J m−2) experimentally estimated value graphite (≈0.37 m−2),19 meaning not difficult exfoliate theoretical strength σ computing maximum derivative Ecl 1b. (1.2–2.1 GPa) lower (≈2.1 GPa),20 further feasible We next electronic monolayers. computed Heyd–Scuseria–Ernzerhof (HSE06) functional 1c 2. S3 MnPS3 semiconductors 3.14 2.32 eV, respectively, report.12 valence (VBM) conduction minimum (CBM) located K point. Other indirect-band-gap semiconductors. More details provided understand compositions VBM CBM partial density states (PDOS) computed. 1d all originate p S/Se d atoms, PDOS indicate 1.90 3.44 exceed free 1.23 eV. In addition magnitude gap, must straddle redox potentials water. work functions S4 For reaction, depends on pH value.[16],21 standard reduction H+/H2 oxidation O2/H2O . Considering selenides unstable acidic environment, neutral environment 7) also calculated. schematic diagram 3 Except FePSe3, whose 7, rest compounds 7. candidates water-splitting bias voltage. fascinatingly, besides advantages suitable condition capture fraction spectrum because counts 40% spectrum. performance coefficient 4. parts ε2 dielectric function defined decay intensity spreading medium. MnPSe3, NiPS3 obvious among them, stronger. activity environment. there two peaks absorption. Besides, direct make advantageous over materials. better layer number bilayer considered. Figures S5–S7 catalytic evaluate effective mass quantitative evaluation ability electron/hole specific direction. masses (me*) (mh*) fitting parabolic VBM, 1, me* mh* direction (Figure 1a) calculated, general smaller common photocatalysts.22 compute DP constant E1, position respect vacuum level strain ε S8 On basis |m*|, C2D, |E1|, room temperature (T 300 K) 1. electron S−1 while hole 34.7 S−1. semiconductors, MoS2 (≈200 S−1),23 hydrogenated (≈105 S−1), fluorinated (≈45 BN (≈487 BC2N (≈180 S−1).24 huge difference between pairs small probability recombination photogenerated carriers. addition, surface available reactions, reduced carriers.[15] Overall, features, into H2 O2 simultaneously, 0–7), mobility, synthesis Thus, candidate conclusion, structure phosphorus trichalcogenides first-principles computations, exfoliating bulk. edge accurate HSE06 predict exhibits our calculations illustrate reflect based (DFT) performed plan-wave set implemented Vienna ab initio simulation package (VASP).25 projector augmented wave (PAW) used describe ion–electron interaction.26 generalized gradient approximation (GGA) expressed Perdew, Burke, Ernzerhof (PBE).27 A 500 eV cutoff plane-wave set. DFT-D3 Becke–Jonson damping adopted accurately account van der Waals force weak interactions.28 Monkhorst–Pack k-point mesh 7 × 1 sheet, 2 selenide 6 5 sulfide study systems periodic boundary conditions (PBC), space least 15 Å inserted sheets periodically repeated images. considering GGA systematically underestimates gaps,29 hybrid functional.30 computation dispersion spectrums CASTEP code finite displacement Materials Studio.31 This supported NSFC (21421001) MOE Innovation Team (IRT13022) China. Magic Cube Shanghai Supercomputer Center. service authors readers, this journal provides supporting information supplied authors. Such peer reviewed may re-organized online delivery, but copy-edited typeset. Technical support issues arising (other missing files) addressed Please note: publisher responsible content functionality any Any queries content) directed author article.

Language: Английский

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Few‐Layer Black Phosphorus Nanosheets as Electrocatalysts for Highly Efficient Oxygen Evolution Reaction

Advanced Energy Materials, Journal Year: 2017, Volume and Issue: 7(19)

Published: June 14, 2017

Abstract Black phosphorus (BP) is a new rediscovered layered material, which has attracted enormous interests in the field of electrocatalysis. Recent investigations reveal that bulk BP promising electrocatalyst for oxygen evolution reactions (OER), whereas its crystal structure restricts sufficient active sites achieving highly efficient OER catalytic performances. Toward this end, few‐layer nanosheets prepared by facile liquid exfoliation are applied as electrocatalysts and exhibit preferable electrocatalytic activity association with structural robustness; subsequently, dependence current density bias potential on concentration OH − also been uncovered. Most importantly, we aware reduction thickness would generate extra from ultrathin planar complimenting to activities. It further anticipated work might provide implementation about performance nanosheets, thereby, offering extendable availabilities BP‐based constructing high‐performance devices.

Language: Английский

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Porous TiO₂ Nanotubes with Spatially Separated Platinum and CoO_x Cocatalysts Produced by Atomic Layer Deposition for Photocatalytic Hydrogen Production

Angewandte Chemie International Edition, Journal Year: 2016, Volume and Issue: 56(3), P. 816 - 820

Published: Dec. 14, 2016

Abstract Efficient separation of photogenerated electrons and holes, associated surface reactions, is a crucial aspect efficient semiconductor photocatalytic systems employed for hydrogen production. A new CoO x /TiO 2 /Pt photocatalyst produced by template‐assisted atomic layer deposition reported production on Pt dual cocatalysts. nanoclusters acting as electron collectors active sites the reduction reaction are deposited inner porous TiO nanotubes, while hole oxidation outer nanotubes. photocatalyst, comprising ultra‐low concentrations noble (0.046 wt %) (0.019 simultaneously with one cycle, achieves remarkably high efficiency (275.9 μmol h −1 ), which nearly five times that pristine nanotubes (56.5 ). The highly dispersed nanoclusters, structure large specific area, synergetic effect spatially separated cocatalysts contribute to excellent activity.

Language: Английский

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Elemental two-dimensional nanosheets beyond graphene

Chemical Society Reviews, Journal Year: 2017, Volume and Issue: 46(8), P. 2127 - 2157

Published: Jan. 1, 2017

The recent progress of elemental two-dimensional nanosheets, beyond graphene, has been summarized with the focus on their preparation and applications.

Language: Английский

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Black phosphorus quantum dots: synthesis, properties, functionalized modification and applications

Chemical Society Reviews, Journal Year: 2018, Volume and Issue: 47(17), P. 6795 - 6823

Published: Jan. 1, 2018

This review article provides the first systematic summary of zero-dimensional black phosphorus quantum dots, from their synthetic methods, properties, and functionalized modification to applications.

Language: Английский

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