Edge-Site Nanoengineering of WS2 by Low-Temperature Plasma-Enhanced Atomic Layer Deposition for Electrocatalytic Hydrogen Evolution

Edge-enriched transition metal dichalcogenides, such as WS2, are promising electrocatalysts for sustainable production of H2 through the electrochemical hydrogen evolution reaction (HER). The reliable and controlled growth of such edge-enriched electrocatalysts at low temperatures has, however, remained elusive. In this work, we demonstrate how plasma-enhanced atomic layer deposition (PEALD) can be used as a new approach to nanoengineer and enhance the HER performance of WS2 by maximizing the density of reactive edge sites at a low temperature of 300 °C. By altering the plasma gas composition from H2S to H2 + H2S during PEALD, we could precisely control the morphology and composition and, consequently, the edge-site density as well as chemistry in our WS2 films. The precise control over edge-site density was verified by evaluating the number of exposed edge sites using electrochemical copper underpotential depositions. Subsequently, we demonstrate the HER performance of the edge-enriched WS2 electrocatalyst, and a clear correlation among plasma conditions, edge-site density, and the HER performance is obtained. Additionally, using density functional theory calculations we provide insights and explain how the addition of H2 to the H2S plasma impacts the PEALD growth behavior and, consequently, the material properties, when compared to only H2S plasma.

[1]  Fei Meng,et al.  Highly active hydrogen evolution catalysis from metallic WS2 nanosheets , 2014 .

[2]  S. D. Elliott,et al.  Multiple Proton Diffusion and Film Densification in Atomic Layer Deposition Modeled by Density Functional Theory , 2013 .

[3]  A. Kucernak,et al.  Determination of the platinum and ruthenium surface areas in platinum-ruthenium alloy electrocatalysts by underpotential deposition of copper. I. Unsupported catalysts , 2002 .

[4]  S. George.  Atomic layer deposition: an overview. , 2010, Chemical reviews.

[5]  I. Chorkendorff,et al.  Biomimetic Hydrogen Evolution: MoS2 Nanoparticles as Catalyst for Hydrogen Evolution , 2005 .

[6]  Hua Zhang,et al.  Lithiation-induced amorphization of Pd3P2S8 for highly efficient hydrogen evolution , 2018, Nature Catalysis.

[7]  Hua Zhang,et al.  The chemistry of two-dimensional layered transition metal dichalcogenide nanosheets. , 2013, Nature chemistry.

[8]  F. Jellinek,et al.  Crystal structures of tungsten disulfide and diselenide , 1987 .

[9]  A. Bol,et al.  Initial stage of atomic layer deposition of 2 D-MoS 2 on SiO 2 surface : a DFT study , 2018 .

[10]  Kai-Erik Elers,et al.  Film Uniformity in Atomic Layer Deposition , 2006 .

[11]  Fei Meng,et al.  Enhanced hydrogen evolution catalysis from chemically exfoliated metallic MoS2 nanosheets. , 2013, Journal of the American Chemical Society.

[12]  Lain‐Jong Li,et al.  Comparative study on MoS2 and WS2 for electrocatalytic water splitting , 2013 .

[13]  M. Karppinen,et al.  Conducting Nb-doped TiO2 thin films fabricated with an atomic layer deposition technique , 2014 .

[14]  Zhongfan Liu,et al.  Chemical vapor deposition of monolayer WS2 nanosheets on Au foils toward direct application in hydrogen evolution , 2015, Nano Research.

[15]  Blöchl,et al.  Projector augmented-wave method. , 1994, Physical review. B, Condensed matter.

[16]  N. Biyikli,et al.  Atomic layer deposition: an enabling technology for the growth of functional nanoscale semiconductors , 2017 .

[17]  Xin Wang,et al.  Recent Development of Molybdenum Sulfides as Advanced Electrocatalysts for Hydrogen Evolution Reaction , 2014 .

[18]  Jacob Bonde,et al.  Biomimetic hydrogen evolution: MoS2 nanoparticles as catalyst for hydrogen evolution. , 2005, Journal of the American Chemical Society.

[19]  Jian Sun,et al.  Enhanced Catalytic Activities of Surfactant-Assisted Exfoliated WS₂ Nanodots for Hydrogen Evolution. , 2016, ACS nano.

[20]  H. Terrones,et al.  Multivalency-Induced Band Gap Opening at MoS2 Edges , 2015 .

[21]  Jonghwa Eom,et al.  High-mobility and air-stable single-layer WS2 field-effect transistors sandwiched between chemical vapor deposition-grown hexagonal BN films , 2015, Scientific Reports.

[22]  Uncovering edge states and electrical inhomogeneity in MoS2 field-effect transistors , 2016, Proceedings of the National Academy of Sciences.

[23]  Xile Hu,et al.  Recent developments of molybdenum and tungsten sulfides as hydrogen evolution catalysts , 2011 .

[24]  Pekka Soininen,et al.  Perfectly Conformal TiN and Al2O3 Films Deposited by Atomic Layer Deposition , 1999 .

[25]  Yi Cui,et al.  Electrochemical Tuning of MoS 2 Nanoparticles on Three-Dimensional Substrate for E ffi cient Hydrogen Evolution , 2014 .

[26]  Changdeuck Bae,et al.  Edge-On MoS2 Thin Films by Atomic Layer Deposition for Understanding the Interplay between the Active Area and Hydrogen Evolution Reaction , 2017 .

[27]  Qing Zhang,et al.  Few-layer MoS2: a promising layered semiconductor. , 2014, ACS nano.

[28]  Gunuk Wang,et al.  Enhanced Electrocatalysis for Hydrogen Evolution Reactions from WS2 Nanoribbons , 2014 .

[29]  Hisato Yamaguchi,et al.  Enhanced catalytic activity in strained chemically exfoliated WS₂ nanosheets for hydrogen evolution. , 2012, Nature Materials.

[30]  Yeonwoong Jung,et al.  One-Step Synthesis of MoS₂/WS₂ Layered Heterostructures and Catalytic Activity of Defective Transition Metal Dichalcogenide Films. , 2016, ACS nano.

[31]  M. Verheijen,et al.  Atomic layer deposition of B-doped ZnO using triisopropyl borate as the boron precursor and comparison with Al-doped ZnO , 2015 .

[32]  J. Shan,et al.  Photonics and optoelectronics of 2D semiconductor transition metal dichalcogenides , 2016, Nature Photonics.

[33]  Ruitao Lv,et al.  Extraordinary room-temperature photoluminescence in triangular WS2 monolayers. , 2012, Nano letters.

[34]  Thomas F. Jaramillo,et al.  Identification of Active Edge Sites for Electrochemical H2 Evolution from MoS2 Nanocatalysts , 2007, Science.

[35]  Hafner,et al.  Ab initio molecular dynamics for liquid metals. , 1995, Physical review. B, Condensed matter.

[36]  D. Bowler,et al.  Chemical accuracy for the van der Waals density functional , 2009, Journal of physics. Condensed matter : an Institute of Physics journal.

[37]  J. Hofmann,et al.  Enhancing the electrocatalytic activity of 2H-WS2 for hydrogen evolution via defect engineering. , 2019, Physical chemistry chemical physics : PCCP.

[38]  S. Luo,et al.  Vertically Aligned Ultrathin 1T-WS2 Nanosheets Enhanced the Electrocatalytic Hydrogen Evolution , 2018, Nanoscale Research Letters.

[39]  H. Fei,et al.  Vertically Aligned WS2 Nanosheets for Water Splitting , 2015 .

[40]  Charlie Tsai,et al.  Activating and optimizing MoS2 basal planes for hydrogen evolution through the formation of strained sulphur vacancies. , 2016, Nature materials.

[41]  Soo‐Hyun Kim,et al.  Low-temperature direct synthesis of high quality WS2 thin films by plasma-enhanced atomic layer deposition for energy related applications , 2018, Applied Surface Science.

[42]  Michael S. Fuhrer,et al.  High mobility ambipolar MoS2 field-effect transistors: Substrate and dielectric effects , 2012, 1212.6292.

[43]  J. Shan,et al.  Atomically thin MoS₂: a new direct-gap semiconductor. , 2010, Physical review letters.

[44]  D. Bowler,et al.  Van der Waals density functionals applied to solids , 2011, 1102.1358.

[45]  Mikko Ritala,et al.  Atomic layer deposition (ALD): from precursors to thin film structures , 2002 .

[46]  Xiang Zhang,et al.  Edge Nonlinear Optics on a MoS2 Atomic Monolayer , 2014, Science.

[47]  Mahdi Shirazi,et al.  Atomistic kinetic Monte Carlo study of atomic layer deposition derived from density functional theory , 2014, J. Comput. Chem..

[48]  Zhichuan J. Xu,et al.  Vertically oriented MoS2 and WS2 nanosheets directly grown on carbon cloth as efficient and stable 3-dimensional hydrogen-evolving cathodes , 2015 .

[49]  Zhenyu Jin,et al.  High turnover frequency of hydrogen evolution reaction on amorphous MoS2 thin film directly grown by atomic layer deposition. , 2015, Langmuir : the ACS journal of surfaces and colloids.

[50]  Hong Liu,et al.  Edge dominated electronic properties of MoS2/graphene hybrid 2D materials: edge state, electron coupling and work function , 2017 .

[51]  W. R. Angus.  The Identification of Molecular Spectra , 1941, Nature.

[52]  Hongzheng Chen,et al.  Graphene-like two-dimensional materials. , 2013, Chemical reviews.

[53]  Yi Cui,et al.  Electrochemical tuning of MoS2 nanoparticles on three-dimensional substrate for efficient hydrogen evolution. , 2014, ACS nano.

[54]  J. Long,et al.  A Molecular MoS2 Edge Site Mimic for Catalytic Hydrogen Generation , 2012, Science.

[55]  B. Fang,et al.  WS2 nanosheets as a highly efficient electrocatalyst for hydrogen evolution reaction , 2012 .

[56]  R. Sundaram,et al.  Low-temperature plasma-enhanced atomic layer deposition of 2-D MoS2: large area, thickness control and tuneable morphology. , 2018, Nanoscale.

[57]  Qing Hua Wang,et al.  Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. , 2012, Nature nanotechnology.

[58]  Xiaohe Liu,et al.  Novel WS 2 /WO 3 heterostructured nanosheets as efficient electrocatalyst for hydrogen evolution reaction , 2017 .

[59]  J. Nørskov,et al.  Chemistry of one-dimensional metallic edge states in MoS2 nanoclusters , 2003 .

[60]  J. Warner,et al.  Edge-Enriched 2D MoS2 Thin Films Grown by Chemical Vapor Deposition for Enhanced Catalytic Performance , 2017 .

[61]  Thomas F. Jaramillo,et al.  Amorphous Molybdenum Sulfide Catalysts for Electrochemical Hydrogen Production: Insights into the Origin of their Catalytic Activity , 2012 .

[62]  A. Bol,et al.  Plasma-enhanced atomic layer deposition of tungsten oxide thin films using (tBuN)2(Me2N)2W and O2 plasma , 2018 .

[63]  C. Detavernier,et al.  Plasma enhanced atomic layer deposition of aluminum sulfide thin films , 2018 .

[64]  Burke,et al.  Generalized Gradient Approximation Made Simple. , 1996, Physical review letters.

[65]  Qiang Fu,et al.  Catalysis with two-dimensional materials and their heterostructures. , 2016, Nature nanotechnology.

[66]  Hua Zhang.  Ultrathin Two-Dimensional Nanomaterials. , 2015, ACS nano.

[67]  Thomas F. Jaramillo,et al.  Catalyzing the Hydrogen Evolution Reaction (HER) with Molybdenum Sulfide Nanomaterials , 2014 .

[68]  Desheng Kong,et al.  Synthesis of MoS2 and MoSe2 films with vertically aligned layers. , 2013, Nano letters.

[69]  A. Klein,et al.  Density-functional-theory calculations of electronic band structure of single-crystal and single-layer WS 2 , 2002 .

[70]  Se Stephen Potts,et al.  Plasma-Assisted Atomic Layer Deposition: Basics, Opportunities, and Challenges , 2011 .

[71]  T. Jaramillo,et al.  Building an appropriate active-site motif into a hydrogen-evolution catalyst with thiomolybdate [Mo3S13]2- clusters. , 2014, Nature chemistry.

[72]  Jinlan Wang,et al.  Activating Inert Basal Planes of MoS2 for Hydrogen Evolution Reaction through the Formation of Different Intrinsic Defects , 2016 .

[73]  A. Radenović,et al.  Single-layer MoS2 transistors. , 2011, Nature nanotechnology.

[74]  Robert Vajtai,et al.  Defects Engineered Monolayer MoS2 for Improved Hydrogen Evolution Reaction. , 2016, Nano letters.

[75]  Yanguang Li,et al.  Ultrathin WS2 nanoflakes as a high-performance electrocatalyst for the hydrogen evolution reaction. , 2014, Angewandte Chemie.