Defect assisted coupling of a MoS2/TiO2 interface and tuning of its electronic structure

Although MoS2 based heterostructures have drawn increased attention, the van der Waals forces within MoS2 layers make it difficult for the layers to form strong chemical coupled interfaces with other materials. In this paper, we demonstrate the successful strong chemical attachment of MoS2 on TiO2 nanobelts after appropriate surface modifications. The etch-created dangling bonds on TiO2 surfaces facilitate the formation of a steady chemically bonded MoS2/TiO2 interface. With the aid of high resolution transmission electron microscope measurements, the in-plane structure registry of MoS2/TiO2 is unveiled at the atomic scale, which shows that MoS2[1-10] grows along the direction of TiO2[001] and MoS2[110] parallel to TiO2[100] with every six units of MoS2 superimposed on five units of TiO2. Electronically, type II band alignments are realized for all surface treatments. Moreover, the band offsets are delicately correlated to the surface states, which plays a significant role in their photocatalytic performance.

[1]  A. Zecchina,et al.  MoS2 Nanoparticles Decorating Titanate-Nanotube Surfaces: Combined Microscopy, Spectroscopy, and Catalytic Studies. , 2015, Langmuir : the ACS journal of surfaces and colloids.

[2]  S. Luo,et al.  Vertical single or few-layer MoS2 nanosheets rooting into TiO2 nanofibers for highly efficient photocatalytic hydrogen evolution , 2015 .

[3]  Jisheng Pan,et al.  Effect of interfacial coupling on photocatalytic performance of large scale MoS2/TiO2 hetero-thin films , 2015 .

[4]  Yong Zhu,et al.  Photocatalytic H2 evolution on MoS2-TiO2 catalysts synthesized via mechanochemistry. , 2015, Physical chemistry chemical physics : PCCP.

[5]  B. Xiang,et al.  MoS2 nanosheet/TiO2 nanowire hybrid nanostructures for enhanced visible-light photocatalytic activities. , 2014, Chemical communications.

[6]  Xiuyan Li,et al.  Enhanced visible light photocatalytic activity for the hybrid MoS2/anatase TiO2(0 0 1) nanocomposite: A first-principles study , 2014 .

[7]  Y. Feng,et al.  Atomic N Modified Rutile TiO2(110) Surface Layer with Significant Visible Light Photoactivity , 2014 .

[8]  Abdullah M. Asiri,et al.  One-step solvothermal synthesis of MoS2/TiO2 nanocomposites with enhanced photocatalytic H2 production , 2013, Journal of Nanoparticle Research.

[9]  Tuqiao Zhang,et al.  Preparation of SiO2@Au@TiO2 core–shell nanostructures and their photocatalytic activities under visible light irradiation , 2013 .

[10]  Z. Yin,et al.  Synthesis of few-layer MoS2 nanosheet-coated TiO2 nanobelt heterostructures for enhanced photocatalytic activities. , 2013, Small.

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

[12]  Yu‐Chuan Lin,et al.  Growth of large-area and highly crystalline MoS2 thin layers on insulating substrates. , 2012, Nano letters.

[13]  Z. Yin,et al.  Single-layer MoS2 phototransistors. , 2012, ACS nano.

[14]  M. T. Martínez,et al.  Preparation of a TiO 2 -MoS 2 nanoparticle-based composite by solvothermal method with enhanced photoactivity for the degradation of organic molecules in water under UV light , 2011 .

[15]  Hisato Yamaguchi,et al.  Photoluminescence from chemically exfoliated MoS2. , 2011, Nano letters.

[16]  Xiujian Zhao,et al.  Tuning the relative concentration ratio of bulk defects to surface defects in TiO2 nanocrystals leads to high photocatalytic efficiency. , 2011, Journal of the American Chemical Society.

[17]  Kun Chang,et al.  L-cysteine-assisted synthesis of layered MoS₂/graphene composites with excellent electrochemical performances for lithium ion batteries. , 2011, ACS nano.

[18]  T. Akita,et al.  Facile synthesis and catalytic activity of MoS(2)/TiO(2) by a photodeposition-based technique and its oxidized derivative MoO(3)/TiO(2) with a unique photochromism. , 2011, Journal of colloid and interface science.

[19]  Xiaobo Chen,et al.  Increasing Solar Absorption for Photocatalysis with Black Hydrogenated Titanium Dioxide Nanocrystals , 2011, Science.

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

[21]  Changgu Lee,et al.  Frictional Characteristics of Atomically Thin Sheets , 2010, Science.

[22]  Yufu Xu,et al.  Synthesis of nano-MoS2/TiO2 composite and its catalytic degradation effect on methyl orange , 2010 .

[23]  A. Manivannan,et al.  Origin of photocatalytic activity of nitrogen-doped TiO2 nanobelts. , 2009, Journal of the American Chemical Society.

[24]  Y. Nakato,et al.  Dependence of the Work Function of TiO2 (Rutile) on Crystal Faces, Studied by a Scanning Auger Microprobe , 2007 .

[25]  J. White,et al.  Selectivity changes during organic photooxidation on TiO2: Role of O2 pressure and organic coverage , 2006 .

[26]  A. Fujishima,et al.  TiO2 Photocatalysis: A Historical Overview and Future Prospects , 2005 .

[27]  J. Yates,et al.  Monitoring hole trapping in photoexcited TiO2(110) using a surface photoreaction. , 2005, The journal of physical chemistry. B.

[28]  K. Novoselov,et al.  Two-dimensional atomic crystals. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[29]  J. White,et al.  Photoinduced Redox Reaction Coupled with Limited Electron Mobility at Metal Oxide Surface , 2004 .

[30]  Jiaguo Yu,et al.  Preparation and photocatalytic behavior of MoS2 and WS2 nanocluster sensitized TiO2. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[31]  J. White,et al.  Photochemical charge transfer and trapping at the interface between an organic adlayer and an oxide semiconductor. , 2003, Journal of the American Chemical Society.

[32]  R. Asahi,et al.  Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides , 2001, Science.

[33]  Yongli He,et al.  Raman scattering study on anatase TiO2 nanocrystals , 2000 .

[34]  J. Ocaña,et al.  A theoretical method for the calculation of frequency- and temperature-dependent interaction constants applicable to the predictive assessment of laser materials processing , 2000 .

[35]  J. Yates,et al.  Photocatalysis on TiO2 Surfaces: Principles, Mechanisms, and Selected Results , 1995 .

[36]  Timothy Hughbanks,et al.  Structural-electronic relationships in inorganic solids: powder neutron diffraction studies of the rutile and anatase polymorphs of titanium dioxide at 15 and 295 K , 1987 .

[37]  K. Liang,et al.  UPS investigation of poorly crystallized MoS2 , 1984 .

[38]  M. Graetzel,et al.  Visible light induced water cleavage in colloidal solutions of chromium-doped titanium dioxide particles , 1982 .

[39]  Ulrike Diebold,et al.  The surface science of titanium dioxide , 2003 .

[40]  Michael Grätzel,et al.  Photochemical cleavage of water by photocatalysis , 1981, Nature.