Thermal hydrogenation of diamond surfaces studied by diffuse reflectance Fourier-transform infrared, temperature-programmed desorption and laser Raman spectroscopy

Ando, Toshihiro; Ishii, M.; Kamo, Mutsukazu; Sato, Yoichiro

doi:10.1039/ft9938901783

Cited by 113 publications

(78 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Groups with specific chemical bonds (such as hydroxyl, carbonyl, carboxylic, and epoxy) absorb light energy and is inherently illuminated with a frequency corresponding to the fundamental vibration. 87 Raman spectroscopy measures the frequencies of Raman-scattered monochromatic light. In fact, Raman spectroscopy provides sufficient chemical information, which is supplementary to FTIR.…”

Section: Structural Characterizationmentioning

confidence: 99%

Graphene-based transition metal oxide nanocomposites for the oxygen reduction reaction

et al. 2015

View full text Add to dashboard Cite

The development of low cost, durable and efficient nanocatalysts to substitute expensive and rare noble metals (e.g. Pt, Au and Pd) in overcoming the sluggish kinetic process of the oxygen reduction reaction (ORR) is essential to satisfy the demand for sustainable energy conversion and storage in the future. Graphene based transition metal oxide nanocomposites have extensively been proven to be a type of promising highly efficient and economic nanocatalyst for optimizing the ORR to solve the world-wide energy crisis. Synthesized nanocomposites exhibit synergetic advantages and avoid the respective disadvantages.In this feature article, we concentrate on the recent leading works of different categories of introduced transition metal oxides on graphene: from the commonly-used classes (FeO x , MnO x , and CoO x ) to some rare and heat-studied issues (TiO x , NiCoO x and Co-MnO x ). Moreover, the morphologies of the supported oxides on graphene with various dimensional nanostructures, such as one dimensional nanocrystals, two dimensional nanosheets/nanoplates and some special multidimensional frameworks are further reviewed.The strategies used to synthesize and characterize these well-designed nanocomposites and their superior properties for the ORR compared to the traditional catalysts are carefully summarized. This work aims to highlight the meaning of the multiphase establishment of graphene-based transition metal oxide nanocomposites and its structural-dependent ORR performance and mechanisms.

show abstract

Section: Structural Characterizationmentioning

confidence: 99%

Graphene-based transition metal oxide nanocomposites for the oxygen reduction reaction

et al. 2015

View full text Add to dashboard Cite

show abstract

“…On the other hand, the surface of diamonds grown by the chemical vapor deposition (CVD) method, which can produce high quality films for practical use, has a hydrogen (H)-chemisorbed structure. It is well-known that the CVD-diamond surface can be stabilized as an H-chemisorbed structure with sp 3 hybridization [2,3]. It has been reported that hydrogenated diamonds exhibit surface electrical conductivity [4,5], and that a sub-surface hole accumulation layer in these diamonds is responsible for this phenomenon [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…It has been reported that hydrogenated diamonds exhibit surface electrical conductivity [4,5], and that a sub-surface hole accumulation layer in these diamonds is responsible for this phenomenon [6,7]. We previously reported that the H-chemisorption of the diamond surface gradually changed to O-chemisorption by surface oxidation based on chemical reactions at a temperature range of 300-350˚C [2,3]. The relationship between the change in the chemisorbed structures on the diamond surface and the surface conductivity has not yet been elucidated.…”

Section: Introductionmentioning

confidence: 99%

Surface conductivity change by oxidation of the homoepitaxially grown diamond (100) surface

Gamo

Iwasaki

Nakagawa

et al. 2007

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Abstract. We have investigated the electrical conductivity change that occurs by oxidation of a homoepitaxially grown diamond (100) surface. For this purpose, atomically flat diamond (100) surfaces homoepitaxially grown by a microwave plasma-assisted chemical vapor deposition (MPCVD) were prepared. It is well-known that a CVD-grown diamond surface is a hydrogen-chemisorbed structure. Surface chemisorbed structures of diamond can be controlled by oxidation in air at temperatures from 25˚C up to 350˚C. The degree of oxygen-chemisorption on the diamond surfaces was analyzed by X-ray photoelectron spectroscopy (XPS). The electrical resistivity (or conductivity) of the diamond surfaces was measured at room temperature under nitrogen flow by using the van der Pauw four-probe system. The surface resistivity of diamond was drastically increased at 300-350˚C, a temperature range corresponding to the beginning point of surface oxidation of a diamond analyzed by the XPS.

show abstract

“…respectively. Figure 6 b shows the correlation between the intensity of the 810 cm 1 peak and the broad band at 1200-950 cm 1 . Similarly, Fig.…”

Section: CMmentioning

confidence: 99%

“…Four or five samples were prepared for each condition. DRIFT spectra of three different portions of the samples in the range of 4000-400 cm 1 were obtained in dry air atmosphere with no dilution. For each spectrum, 256 scans were accumulated at a resolution of 4 cm 1 .…”

Section: Introductionmentioning

confidence: 99%

Surface Modification of Diamond Powder with Formaldehyde Solution

Visbal

Ishizaki

2005

J. Ceram. Soc. Japan

View full text Add to dashboard Cite

Surface modification of diamond powder 5-12 mm was achieved using a water-saturated solution of formaldehyde. The effects of the reaction temperature and time were studied. The diamond surface was characterized by diffuse reflectance infrared Fourier transform DRIFT spectroscopy. Four chemical structures; epoxyas well as methyl CH 3 and methyne CH bands were identified in the diamond surface after the treatment. The total intensity of the bands increases proportionally by augmenting the treatment time and temperature. The absorbance intensity of all bands correlates linearly. An activation energy of 34.7 kJ mol 1 was obtained, that is in the range of a chemisorption reaction energy. From the results it is concluded that methyl formate HCOOCH 3 was chemisorbed on the diamond surface to a carbon with two unsaturated valences.=Received December 9, 2004; Accepted January 20, 2005?Key-words : Diamond powder, Surface modification, Chemisorption, Formaldehyde solution, Diffuse reflectance infrared fourier transform DRIFT spectroscopy 1. Introduction Diamond is a well-known promising industrial material for different applications because of its properties. The surface condition of diamond strongly affects its chemical and physical properties. Several studies have been focused on diamond powder surface modification. They can be classified into two main groups: modifications in vapor phase 1 -7 and in liquid phase.8 -14 The formers are costly processes for industrial applications because of the special attention needed of reactive gases at high temperatures and highly expensive equipments. Modifications in the liquid phase are more suitable for industrial applications, because the common technology of chemical engineering can be used. Another advantage is that organic substances with organic functional groups can be chemisorbed on a diamond surface and new organic-inorganic functional materials can be developed. For example, a material with the physical properties of diamond hardness, thermal conductivity, large band gap, etc. and the chemical functions of the organic functional groups could be fabricated. According to our knowledge, there have been no reports on modifying diamond surface using a formaldehyde solution and its mechanism. In this paper, we report about the feasibility of modifying the surface of diamond powder by dissolution of formaldehyde in water. The diamond surface after this treatment was characterized by diffuse reflectance infrared Fourier transform DRIFT spectroscopy. The reaction between the species formed in the dissolution of formaldehyde in water and the diamond powder is also discussed. The treatment was studied at several reaction temperatures and times.

show abstract

Thermal hydrogenation of diamond surfaces studied by diffuse reflectance Fourier-transform infrared, temperature-programmed desorption and laser Raman spectroscopy

Cited by 113 publications

References 15 publications

Graphene-based transition metal oxide nanocomposites for the oxygen reduction reaction

Graphene-based transition metal oxide nanocomposites for the oxygen reduction reaction

Surface conductivity change by oxidation of the homoepitaxially grown diamond (100) surface

Surface Modification of Diamond Powder with Formaldehyde Solution

Contact Info

Product

Resources

About