scholarly journals A Simple and Soft Chemical Deaggregation Method Producing Single-Digit Detonation Nanodiamonds

2020 ◽  
Author(s):  
Daiki Terada ◽  
Frederick T.-K. So ◽  
Bodo Hattendorf ◽  
Eiji Ōsawa ◽  
Masahiro Shirakawa ◽  
...  
Keyword(s):  
Acid Treatment ◽  
Detonation Nanodiamonds ◽  
Chemistry Laboratory ◽  
Full Potential ◽  
Single Digit ◽  
Primary Metal ◽  
Wide Ph Range ◽  
Oxidation In Air ◽  
Ph Range ◽  
Fluorescent Biomarkers

<p>Detonation nanodiamonds (DNDs) are a class of very small and spherical diamond nanocrystals. Used in polymer reinforcement materials, as drug delivery systems or as fluorescent biomarkers, only the final deaggregation step down to the single-digit nanometer size unfolds their full potential. All existing deaggregation methods rely on mechanical forces, such as high-power sonication or beads milling. We report a purely chemical deaggregation method by combining oxidation in air followed by a boiling acid treatment. Our DNDs are surface functionalized with carboxyl groups, the final boiling acid treatment removes primary metal contaminants and the nanoparticles remain dispersed over a wide pH range. Experiments can be easily carried out in a standard chemistry laboratory. This is a key step for many DND-based applications, ranging from material science to biological or medical applications and opens a way for inexpensive mass production on industrial scale.</p>

scholarly journals A Simple and Soft Chemical Deaggregation Method Producing Single-Digit Detonation Nanodiamonds

2020 ◽  
Author(s):  
Daiki Terada ◽  
Frederick T.-K. So ◽  
Bodo Hattendorf ◽  
Eiji Ōsawa ◽  
Masahiro Shirakawa ◽  
...  
Keyword(s):  
Acid Treatment ◽  
Detonation Nanodiamonds ◽  
Chemistry Laboratory ◽  
Full Potential ◽  
Single Digit ◽  
Primary Metal ◽  
Wide Ph Range ◽  
Oxidation In Air ◽  
Ph Range ◽  
Fluorescent Biomarkers

<p>Detonation nanodiamonds (DNDs) are a class of very small and spherical diamond nanocrystals. Used in polymer reinforcement materials, as drug delivery systems or as fluorescent biomarkers, only the final deaggregation step down to the single-digit nanometer size unfolds their full potential. All existing deaggregation methods rely on mechanical forces, such as high-power sonication or beads milling. We report a purely chemical deaggregation method by combining oxidation in air followed by a boiling acid treatment. Our DNDs are surface functionalized with carboxyl groups, the final boiling acid treatment removes primary metal contaminants and the nanoparticles remain dispersed over a wide pH range. Experiments can be easily carried out in a standard chemistry laboratory. This is a key step for many DND-based applications, ranging from material science to biological or medical applications and opens a way for inexpensive mass production on industrial scale.</p>

Polarographic and spectrophotometric behaviour of some N-p-phenyl substituted benzamidines

1991 ◽  
Vol 56 (12) ◽  
pp. 2791-2799 ◽  
Author(s):  
Juan A. Squella ◽  
Luis J. Nuñez-Vergara ◽  
Hernan Rodríguez ◽  
Amelia Márquez ◽  
Jose M. Rodríguez-Mellado ◽  
...  
Keyword(s):  
Spectrophotometric Study ◽  
Absorption Bands ◽  
Electrochemical Parameters ◽  
Wide Ph Range ◽  
Group A ◽  
Substituent Constants ◽  
Ph Range ◽  
The Waves

Five N-p-phenyl substituted benzamidines were studied by DC and DP polarography in a wide pH range. Coulometric results show that the overall processes are four-electron reductions. Logarithmic analysis of the waves indicate that the process are irreversible. The influence of the pH on the polarographic parameters was also studied. A UV spectrophotometric study was performed in the pH range 2-13. In basic media some variations in the absorption bands were observed due to the dissociation of the amidine group. A determination of the pK values was made by deconvolution of the spectra. Correlations of both the electrochemical parameters and spectrophotometric pK values with the Hammett substituent constants were obtained.

High degradation efficiency of sulfamethazine with the dual-reaction-center Fe-Mn-SiO2 Fenton-like nanocatalyst in a wide pH range

2021 ◽  
Author(s):  
Manoj Kumar Panjwani ◽  
Qing Wang ◽  
Yueming Ma ◽  
Yuxuan Lin ◽  
Feng Xiao ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Reaction Center ◽  
Degradation Efficiency ◽  
Heterogeneous Fenton ◽  
Wide Ph Range ◽  
Ph Range

The development of a heterogeneous Fenton-like catalyst, possessing high degradation efficiency in a wide pH range, is crucial for wastewater treatment. The Fe-Mn-SiO2 catalyst was designed, and prepared by a...

scholarly journals Defect-Rich Heterogeneous MoS2/rGO/NiS Nanocomposite for Efficient pH-Universal Hydrogen Evolution

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 662 ◽  
Author(s):  
Guangsheng Liu ◽  
Kunyapat Thummavichai ◽  
Xuefeng Lv ◽  
Wenting Chen ◽  
Tingjun Lin ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Reduced Graphene ◽  
Heterogeneous Interfaces ◽  
Wide Ph Range ◽  
Ph Range ◽  
A Current ◽  
Poor Stability

Molybdenum disulfide (MoS2) has been universally demonstrated to be an effective electrocatalytic catalyst for hydrogen evolution reaction (HER). However, the low conductivity, few active sites and poor stability of MoS2-based electrocatalysts hinder its hydrogen evolution performance in a wide pH range. The introduction of other metal phases and carbon materials can create rich interfaces and defects to enhance the activity and stability of the catalyst. Herein, a new defect-rich heterogeneous ternary nanocomposite consisted of MoS2, NiS and reduced graphene oxide (rGO) are synthesized using ultrathin αNi(OH)2 nanowires as the nickel source. The MoS2/rGO/NiS-5 of optimal formulation in 0.5 M H2SO4, 1.0 M KOH and 1.0 M PBS only requires 152, 169 and 209 mV of overpotential to achieve a current density of 10 mA cm−2 (denoted as η10), respectively. The excellent HER performance of the MoS2/rGO/NiS-5 electrocatalyst can be ascribed to the synergistic effect of abundant heterogeneous interfaces in MoS2/rGO/NiS, expanded interlayer spacings, and the addition of high conductivity graphene oxide. The method reported here can provide a new idea for catalyst with Ni-Mo heterojunction, pH-universal and inexpensive hydrogen evolution reaction electrocatalyst.

Sign in / Sign up

Export Citation Format

Share Document