Metal dichalcogenides

Jobic S, Brec R, Rouxel J (1992) Occurrence and characterization of anionic bondings in transition metal dichalcogenides. J AUoy Compd 178 253-283... 

Wilson JA, Yoffe AD (1969) The transition metal dichalcogenides. Discussion and interpretation of the observed optical, electrical and structural properties. Adv Phys 18(73) 193-335... 

Lucovsky G, White RM, Benda JA, ReveUi JE (1973) Infrared-reflectance spectra of layered Group-IV and Group-VI transition-metal dichalcogenides. Phys Rev B 7 3859-3870 Cordes H, Schmid-Fetzer R (1994) Phase equilibria in the U-Te system. J AUoy Compd 216 197-206... 

Tiibutsch H (1978) Hole reactions from d-energy bands of layer type group VI transition metal dichalcogenides New perspectives for electrochemical solar energy conversion. J... 

A critical review on the foundation and earlier results on metal intercalates of the transition metal dichalcogenides and related host materials can be found in the seminal paper of Whittingham [53]. The electrochemical and transport properties... 

Subba Rao GV, Tsang JC (1974) Electrolysis method of intercalation of layered transition metal dichalcogenides. Mater Res BuU 9 921-926... 

The strong interaction of the 13 /I" redox system with the metal dichalcogenide materials was recently exploited (31) to bring about the visible light-driven process representeiTby equation (10). In 50% by weight H2SO4 the reaction as written... 

The suppression of photoanodic corrosion is not always difficult. For example, metal dichalcogenides are not durable in aqueous 0.1 M KC1 equation (11) represents the photoanodic... 

The ability to manipulate the anodic corrosion problem using high concentrations of redox active electrolyte also makes possible the sustained oxidation of Br" at illuminated metal dichalcogenide-based cells, Figure 1.(15) The use of high concentrations of electrolyte has proven valuable in situations involving other photoanode materials, notably n-type Si.(36,37)... 

Scheme IV. Representation of the Is /T mediated oxidation of S02 at illuminated metal dichalcogenide photoanodes (top) and interface energetics with and without If/I in 6 M H2SOh/l M SOt for MoS2 (bottom) (31). In the absence of the mediator system the photovoltage for the S02 oxidation is expected to be negligible. The adsorption of the Is /T is unaffected by the S02 so the negative shift of the fiat band potential can be exploited to give a photovoltage for the desired process with the h /T system simultaneously providing an acceleration of the S02 oxidation.

Ki, W. Huang, X. Li, J. Young, D. L. Zhang, Y. 2007. Highly conductive group VI transition metal dichalcogenide films by solution-processed deposition. J. Mater. Res. 22 1390-1395. 

Herein, criteria are developed for ideal polarizable semiconductor electrode-solution interfaces. A variety of experimental studies involving metal dichalcogenide-solution interfaces are discussed within the context of these criteria. These interfaces approach ideality in most respects and are well suited for fundamental studies involving electron transfer to solution species or adsorbed dyes. 

The authors propose that a major difficulty in interpreting kinetic current flow at the semiconductor-solution interface lies in the inability of experimentalists to prepare interfaces with ideal and measurable properties. In support of this hypothesis, the importance of ideal interfacial properties to metal electrode kinetic studies is briefly reviewed and a set of criteria for ideality of semiconductor-solution interfaces is developed. Finally, the use of semiconducting metal dichalcogenide electrodes as ideal interfaces for subsequent kinetic studies is explored. 

Figure 1. Schematic drawing showing the structure of the trigonal prismatic variety of the metal dichalcogenide structure. Note the structure is not drawn to scale but to emphasize the layered structure of the materials.

Metal Dichalcogenides with Band Gaps Greater than 2 eV... 

The above has been a brief discussion of the use of in-situ, time-resolved EDXRD techniques to study the intercalation reactions of LDHs. A variety of other hosts such as metal dichalcogenides have also been investigated, but these fall outside the scope of this review. 

Chen X, Fan R (2001) Low temperature hydrothermal synthesis of transition metal dichalcogenides. Chem Mater 13 802-805... 

Omloo and Jellinek7 have described the synthesis and characterization of intercalation compounds of alkali metals with the group V layered transition metal dichalcogenides. Typically, these types of intercalation complexes are sensitive to moisture and must be handled in dry argon or nitrogen atmospheres. The alkali metal atoms occupy either octahedral or trigonal prismatic holes between X-M—X slabs. There are two principal means by which these compounds may be prepared. 

IV layered transition metal dichalcogenide-alkali metal intercalation compounds. The advantage of this method is that it is carried out at room temperature and, consequently, there is less likelihood of reaction between sodium and the reaction vessel. On the other hand, this method is more difficult in that it involves the use of liquid NH3. Furthermore, undesirable side reactions may occur if the NH3 is not dried thoroughly or if the reaction vessel is not clean. For example,... 

DiSalvo et al.9 have carried out a systematic survey of intercalation compounds of 2H(a)-TaS2 with post-transition metals. In particular, the system SnxTaS2 was found to exist in two composition domains, 0 < x < /3 and x = 1. The following discussion briefly describes the techniques used by DiSalvo to synthesize the compound SnTaS2. Syntheses of other transition and post-transition metal intercalation complexes with the layered transition metal dichalcogenides are discussed in References 9 and 20-24. 

J. A. Wilson and A. D. Yoffe, Adv. Phys., 18, No. 73, 193-335 (1969). This article offers a complete discussion of the polymorphic phases found in the various layered transition metal dichalcogenides. 

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