scholarly journals Morphology Control in 2D Carbon Nitrides: Impact of Particle Size on Optoelectronic Properties and Photocatalysis

2021 ◽  
pp. 2102468
Author(s):  
Julia Kröger ◽  
Alberto Jiménez‐Solano ◽  
Gökcen Savasci ◽  
Vincent W. h. Lau ◽  
Viola Duppel ◽  
...  
Keyword(s):  
Particle Size ◽  
Morphology Control ◽  
Optoelectronic Properties ◽  
Carbon Nitrides

Fabrication and morphology control of hollow polymer particles by altering core particle size

2014 ◽  
Vol 292 (10) ◽  
pp. 2687-2694 ◽  
Author(s):  
Wei Deng ◽  
Huachao Guo ◽  
Wennan Zhang ◽  
Chengyou Kan
Keyword(s):  
Particle Size ◽  
Morphology Control ◽  
Core Particle ◽  
Polymer Particles

A Comparative Study on the Role of Precursors of Graphitic Carbon Nitrides for the Photocatalytic Degradation of Direct Red 81

2014 ◽  
Vol 807 ◽  
pp. 101-113 ◽  
Author(s):  
J. Theerthagiri ◽  
R.A. Senthil ◽  
J. Madhavan ◽  
B. Neppolian
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Irradiation ◽  
Carbon Nitride ◽  
Light Irradiation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Nitrides

The graphitic carbon nitride (g-C3N4) materials have been synthesized from nitrogen rich precursors such as urea and thiourea by directly heating at 520 °C for 2 h. The as-synthesized carbon nitride samples were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis) absorption spectroscopy, photoluminescence (PL) and particle size analysis. The photoelectrochemical measurements were performed using several on-off cycles under visible-light irradiation. The x-ray diffraction peak is broader which indicates the fine powder nature of the synthesized materials. The estimated crystallite size of carbon nitrides synthesized from urea (U-CN) and thiourea (T-CN) are 4.0 and 4.4 nm respectively. The particle size of U-CN and T-CN were analysed by particle size analyser and were found to be 57.3 and 273.3 nm respectively. The photocatalytic activity for the degradation of the textile dye namely, direct red-81 (DR81) using these carbon nitrides were carried out under visible light irradiation. In the present investigation, a comparison study on the carbon nitrides synthesized from cheap precursors such as urea and thiourea for the degradation of DR81 has been carried out. The results inferred that U-CN exhibited higher photocatalytic activity than T-CN. The photoelectrochemical studies confirmed that the (e--h+) charge carrier separation is more efficient in U-CN than that of T-CN and therefore showed high photocatalytic degradation. Further, the smaller particle size of U-CN is also responsible for the observed degradation trend.

Preparation of Flaky Alumina Powder by Molten Salt Synthesis Method

2014 ◽  
Vol 997 ◽  
pp. 428-432
Author(s):  
Qian Ying Zhang ◽  
Xun Geng
Keyword(s):  
Particle Size ◽  
Molten Salt ◽  
Synthesis Method ◽  
Morphology Control ◽  
Molten Salt Synthesis ◽  
Alumina Powder ◽  
High Quality ◽  
Uniform Size ◽  
Particle Size And Morphology ◽  
Size And Morphology

High-quality flaky α-Al2O3 powder with regular morphology, uniform size, larger diameter-thickness proportion and excellent dispersibility in water and free from agglomeration and staggered growth was obtained on the basis of molten salt synthesis method. The effects of experiment parameter on the particle size and morphology of flaky alumina powder were studied. The mechanism of morphology control was discussed.

The Morphology Control of Nano-Cu2O and Study on its Phototocatalytic Properties in the Treatment of Chromium-Containing Wastewater

2012 ◽  
Vol 482-484 ◽  
pp. 2559-2562
Author(s):  
Bin Zhao ◽  
Di Ma
Keyword(s):  
Particle Size ◽  
Reaction Temperature ◽  
Reduction Method ◽  
Morphology Control ◽  
Chemical Precipitation ◽  
Photocatalytic Properties ◽  
Important Relationship ◽  
Naoh Solution ◽  
Crystal Type

The sphere-like nano-Cu2O was prepared by chemical precipitation and reduction method, the different size of sample was obtained by adjusting reaction temperature and concentration of NaOH solution. Cu2O was characterized by XRD and SEM, respectively. The results indicate that the homogeneity of Cu2O particles is related to the reaction temperature while the crystal type to the concentration of NaOH solution. The effects of the different particle size on the photocatalytic properties in the treatment of chromium(Ⅵ)-containing water was performed, the results show that there exists an important relationship between them, that is the excellent properties can be obtained with smaller size of Cu2O.

scholarly journals Morphology Control in 2D Carbon Nitrides: Impact of Particle Size on Optoelectronic Properties and Photocatalysis

2021 ◽  
Author(s):  
Julia Kröger ◽  
Alberto Jiménez-Solano ◽  
Gökcen Savasci ◽  
Vincent Wing-hei Lau ◽  
Viola Duppel ◽  
...  
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Hydrogen Evolution ◽  
Carbon Nitride ◽  
Colloidal Stability ◽  
Photophysical Properties ◽  
Trap States ◽  
Time Resolved ◽  
Transport Studies ◽  
Carbon Nitrides

The carbon nitride poly(heptazine imide), PHI, has recently emerged as a powerful 2D carbon nitride photocatalyst with intriguing charge storing ability. Yet, insights into how morphology, particle size and defects influence its photophysical properties are virtually absent. Here, ultrasonication is used to systematically tune the particle size as well as concentration of surface functional groups and study their impact. Enhanced photocatalytic activity correlates with an optimal amount of those defects that create shallow trap states in the optical band gap, promoting charge percolation, as evidenced by time-resolved photoluminescence spectroscopy, charge transport studies, and quantum-chemical calculations. Excessive amounts of terminal defects can act as recombination centers and hence, decrease the photocatalytic activity for hydrogen evolution. Re-agglomeration of small particles can, however, partially restore the photocatalytic activity. The type and amount of trap states at the surface can also influence the deposition of the co-catalyst Pt, which is used in hydrogen evolution experiments. Optimized conditions entail improved Pt distribution, as well as an enhanced wettability and colloidal stability. A description of the interplay between these effects is provided to obtain a holistic picture of the size–property–activity relationship in nanoparticulate PHI-type carbon nitrides that can likely be generalized to related photocatalytic systems.<br>

scholarly journals Morphology Control in 2D Carbon Nitrides: Impact of Particle Size on Optoelectronic Properties and Photocatalysis

2021 ◽  
Author(s):  
Julia Kröger ◽  
Alberto Jiménez-Solano ◽  
Gökcen Savasci ◽  
Vincent Wing-hei Lau ◽  
Viola Duppel ◽  
...  
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Hydrogen Evolution ◽  
Carbon Nitride ◽  
Colloidal Stability ◽  
Photophysical Properties ◽  
Trap States ◽  
Time Resolved ◽  
Transport Studies ◽  
Carbon Nitrides

The carbon nitride poly(heptazine imide), PHI, has recently emerged as a powerful 2D carbon nitride photocatalyst with intriguing charge storing ability. Yet, insights into how morphology, particle size and defects influence its photophysical properties are virtually absent. Here, ultrasonication is used to systematically tune the particle size as well as concentration of surface functional groups and study their impact. Enhanced photocatalytic activity correlates with an optimal amount of those defects that create shallow trap states in the optical band gap, promoting charge percolation, as evidenced by time-resolved photoluminescence spectroscopy, charge transport studies, and quantum-chemical calculations. Excessive amounts of terminal defects can act as recombination centers and hence, decrease the photocatalytic activity for hydrogen evolution. Re-agglomeration of small particles can, however, partially restore the photocatalytic activity. The type and amount of trap states at the surface can also influence the deposition of the co-catalyst Pt, which is used in hydrogen evolution experiments. Optimized conditions entail improved Pt distribution, as well as an enhanced wettability and colloidal stability. A description of the interplay between these effects is provided to obtain a holistic picture of the size–property–activity relationship in nanoparticulate PHI-type carbon nitrides that can likely be generalized to related photocatalytic systems.<br>

Sign in / Sign up

Export Citation Format

Share Document