scholarly journals Comparison of Graphitic Carbon Nitrides Synthetized from Melamine and Melamine-Cyanurate Complex: Characterization and Photocatalytic Decomposition of Ofloxacin and Ampicillin

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1967
Author(s):  
Petr Praus ◽  
Aneta Smýkalová ◽  
Kryštof Foniok
Keyword(s):  
Photocatalytic Activity ◽  
Carbon Nitride ◽  
Band Gap Energy ◽  
Graphitic Carbon ◽  
Photocatalytic Decomposition ◽  
Melamine Cyanurate ◽  
Gap Energy ◽  
Complex Characterization ◽  
Led Irradiation ◽  
Content Of Oxygen

Graphitic carbon nitride (g-C3N4, hereafter abbreviated as CN) was prepared by the heating of melamine (CN-M) and melamine-cyanurate complex (CN-MCA), respectively, in air at 550 °C for 4 h. The specific surface area (SSA) of CN-M and CN-MCA was 12 m2 g−1 and 225 m2g−1 and the content of oxygen was 0.62 wt.% and 1.88 wt.%, respectively. The band gap energy (Eg) of CN-M was 2.64 eV and Eg of CN-MCA was 2.73 eV. The photocatalytic activity of the CN materials was tested by means of the decomposition of antibiotics ofloxacin and ampicillin under LED irradiation of 420 nm. The activity of CN-MCA was higher due to its high SSA, which was determined based on the physisorption of nitrogen. Ofloxacin was decomposed more efficiently than ampicillin in the presence of both photocatalysts.

scholarly journals A Comparative Study of the Effect of Graphene Oxide, Graphitic Carbon Nitride, and Their Composite on the Photocatalytic Activity of Cu3SnS4

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 14
Author(s):  
Olalekan C. Olatunde ◽  
Damian C. Onwudiwe
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Carbon Nitride ◽  
Band Gap Energy ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Support Material ◽  
Support Materials ◽  
Gap Energy

Photocatalysis has shown high potential in dealing with the ever-broadening problem of wastewater treatment, escalated by the increasing level of recalcitrant chemicals often referred to as emerging contaminants. In this study, the effect of support material on the photocatalytic activity of copper tin sulfide (Cu3SnS4) nanoparticles for the degradation of tetracycline as an emerging contaminant is presented. Graphene oxide, protonated graphitic carbon nitride, and a composite of graphitic carbon nitride and graphene oxide were explored as support materials for Cu3SnS4 nanoparticles. The nanoparticles were incorporated with the different carbonaceous substrates to afford graphene-supported Cu3SnS4 (GO-CTS), protonated graphitic carbon nitride-supported Cu3SnS4 (PCN-CTS), and graphene oxide/protonated graphitic carbon nitride-supported Cu3SnS4 (GO/PCN-CTS). Physicochemical, structural, and optical properties of the prepared nanocomposites were characterized using techniques such as Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis near infrared, and fluorescence spectrophotometry. The compositing of the Cu3SnS4 nanoparticles on the support materials was confirmed by the characterization techniques, and the optical properties of the composites were found to be influenced by the nature of the support material. The incorporation of CTS into the support materials resulted in a reduction in band gap energy with evaluated band gaps of 1.65, 1.46, 1.43 eV, and 1.16 eV. The reduction in band gap energy suggests the potential of the composites for enhanced photocatalytic activity. From the photocatalytic study, the degradation efficiency of tetracycline by CTS, PCN-CTS, GO-CTS, and PC/GO-CTS was 74.1, 85.2, 90.9, and 96.5%, respectively. All the composites showed enhanced activity compared to pristine CTS, and the existence of a synergy between GO and PCN when both were employed as support materials was observed. Based on the charge carrier recombination characteristics and the band edge potential calculations from the composites, a possible mechanism of action of each composite was proposed. This study therefore confirms the possibility of modulating the mechanism of action and subsequently the efficiency of semiconductor materials by altering the nature of the support material.

scholarly journals Optimized Synthesis Temperature and Time to Obtain Crystalline Carbon Nitride with Enhanced Photocatalytic Activity for Phenol Degradation

2020 ◽  
Vol 20 (6) ◽  
pp. 1392
Author(s):  
Leny Yuliati ◽  
Mohd Hayrie Mohd Hatta ◽  
Siew Ling Lee ◽  
Hendrik Oktendy Lintang
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Band Gap ◽  
Surface Area ◽  
Carbon Nitride ◽  
Phenol Degradation ◽  
Synthesis Temperature ◽  
Band Gap Energy ◽  
Synthesis Time ◽  
Gap Energy

In this work, the crystalline carbon nitride photocatalysts were synthesized by an ionothermal technique with varied synthesis temperature of 500, 550, and 600 °C, and synthesis time of 2, 4, and 6 h. Fourier transform infrared spectra showed the successful formation of the prepared carbon nitrides from their characteristic vibration peaks. X-ray diffraction patterns suggested that the same phase of poly(triazine imide) and heptazine could be observed, but with different crystallinity. The optical properties showed that different temperatures and synthesis time resulted in the different band gap energy (2.72–3.02 eV) as well as the specific surface area (24–73 m2 g–1). The transmission electron microscopy image revealed that the crystalline carbon nitride has a near-hexagonal prismatic crystallite size of about 50 nm. Analysis by high-performance liquid chromatography showed that the best photocatalytic activity for phenol degradation under solar light simulator was obtained on the crystalline carbon nitride prepared at the 550 °C for 4 h, which would be due to the high crystallinity, suitable low band gap energy (2.82 eV), and large specific surface area (73 m2 g–1). Controlling both the temperature and synthesis time is shown to be important to obtain the best physicochemical properties leading to high activity.

scholarly journals Photocatalytic Decomposition of N2O by Using Nanostructured Graphitic Carbon Nitride/Zinc Oxide Photocatalysts Immobilized on Foam

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 735 ◽  
Author(s):  
Kamila Kočí ◽  
Martin Reli ◽  
Ivana Troppová ◽  
Marcel Šihor ◽  
Tereza Bajcarová ◽  
...  
Keyword(s):  
Carbon Nitride ◽  
Cost Effective ◽  
Band Gap Energy ◽  
Photocatalytic Decomposition ◽  
Photocatalytic Reaction ◽  
Photocatalytic Efficiency ◽  
Ultraviolet A ◽  
Electron Hole ◽  
Gap Energy ◽  
Significant Factors

The aim of this work was to deposit cost-effective g-C3N4/ZnO nanocomposite photocatalysts (weight ratios of g-C3N4:ZnO from 0.05:1 to 3:1) as well as pure ZnO and g-C3N4 on Al2O3 foam and to study their photocatalytic efficiency for the photocatalytic decomposition of N2O, which was studied in a home-made batch photoreactor under ultraviolet A irradiation (λ = 365 nm). Based on the photocatalysis measurements, it was found that photocatalytic decomposition of N2O in the presence of all the prepared samples was significantly higher in comparison with photolysis. The photoactivity of the investigated nanocomposite photocatalysts increased in the following order: g-C3N4/ZnO (3:1) ≈ g-C3N4/ZnO (0.45:1) ≤ g-C3N4/ZnO (2:1) ZnO < g-C3N4 < g-C3N4/ZnO (0.05:1). The g-C3N4/ZnO (0.05:1) nanocomposite showed the best photocatalytic behavior and the most effective separation of photoinduced electron–hole pairs from all nanocomposites. The key roles played in photocatalytic activity were the electron–hole separation and the position and potential of the valence and conduction band. On the other hand, the specific surface area and band gap energy were not the significant factors in N2O photocatalytic decomposition. Immobilization of the photocatalyst on the foam permits facile manipulation after photocatalytic reaction and their repeated application.

Cellulose nanofibrils anchored Ag on graphitic carbon nitride for efficient photocatalysis under visible light

2018 ◽  
Vol 5 (9) ◽  
pp. 2129-2143 ◽  
Author(s):  
Cuihua Tian ◽  
Xu Tao ◽  
Sha Luo ◽  
Yan Qing ◽  
Xihong Lu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Carbon Nitride ◽  
Cellulose Nanofibrils ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride

Cellulose nanofibrils were employed to anchor Ag onto a g-C3N4 framework to improve its photocatalytic activity remarkably under visible light.

Photo-accelerated Co3+/Co2+ Transformation on Cobalt and Phosphorus Co-doped g-C3N4 for Fenton-like Reaction

2021 ◽  
Author(s):  
Xiaomei Liu ◽  
Yang Li ◽  
Xiaobin Fan ◽  
Fengbao Zhang ◽  
Guoliang Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Organic Pollutants ◽  
Carbon Nitride ◽  
Reactive Species ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Oxygen Reactive Species ◽  
Co Doped ◽  
Co2 Transformation

Peroxydisulfate (PDS) can be activated by graphitic carbon nitride (g-C3N4) under irradiation, and the generated oxygen reactive species (ROSs) can degrade organic pollutants effectively. However, the photocatalytic activity of pristine...

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