Energy-level dependent H 2 O 2 production on metal-free, carbon-content tunable carbon nitride photocatalysts

In this study, a metal-free carbon nitride (CN) was investigated for the first time as a potential fluorescence sensor for detection of nitrate ions (NO3-). The CN was prepared through thermal polymerization of urea precursor at 823 K and characterized by diffuse reflectance ultraviolet-visible (DR UV-Vis), Fourier transform infrared (FTIR), and fluorescence spectroscopies. The DR UV-Vis spectrum confirmed that CN could absorb light up to 450 nm. On the other hand, the FTIR spectrum revealed the presence of graphitic CN single and double bond characters in the 800-1700 cm-1 region. From the fluorescence spectroscopy, three excitation peaks at 278, 310 and 369 nm were observed due to the presence of N=C, C=O and N-C groups, respectively. The fluorescence sensor capability of the CN was then investigated using concentrations of NO3- in the range of 300-1800 mM. It was confirmed that the intensities of the emission sites were quenched linearly with the concentrations of the NO3-. The CN showed good reproducibility with relative standard deviation (RSD) values were 1.5-7.2%. These results suggested that CN can act as the fluorescence sensor for NO3-.

Download Full-text

The special route toward conversion of methane to methanol on a fluffy metal‐free carbon nitride photocatalyst in the presence of H 2 O 2

International Journal of Energy Research ◽

10.1002/er.5088 ◽

2020 ◽

Vol 44 (4) ◽

pp. 2740-2753 ◽

Cited By ~ 5

Author(s):

Shangli Shi ◽

Zhuxing Sun ◽

Chenyu Bao ◽

Tianshu Gao ◽

Yun Hang Hu

Keyword(s):

Carbon Nitride ◽

Free Carbon ◽

Metal Free ◽

Conversion Of Methane

Download Full-text

Metal-free carbon nitride photocatalysis with in situ hydrogen peroxide generation for the degradation of aromatic compounds

Applied Catalysis B Environmental ◽

10.1016/j.apcatb.2019.03.040 ◽

2019 ◽

Vol 252 ◽

pp. 128-137 ◽

Cited By ~ 21

Author(s):

André Torres-Pinto ◽

Maria J. Sampaio ◽

Cláudia G. Silva ◽

Joaquim L. Faria ◽

Adrián M.T. Silva

Keyword(s):

Hydrogen Peroxide ◽

Aromatic Compounds ◽

Carbon Nitride ◽

Free Carbon ◽

Metal Free ◽

Hydrogen Peroxide Generation

Download Full-text

Photo-assisted simultaneous electrochemical detection of multiple heavy metal ions with a metal-free carbon black anchored graphitic carbon nitride sensor

Analytica Chimica Acta ◽

10.1016/j.aca.2021.338951 ◽

2021 ◽

pp. 338951

Author(s):

Jiayue Hu ◽

Zhi Li ◽

Chuanyang Zhai ◽

Lixi Zeng ◽

Mingshan Zhu

Keyword(s):

Heavy Metal ◽

Carbon Black ◽

Metal Ions ◽

Electrochemical Detection ◽

Heavy Metal Ions ◽

Carbon Nitride ◽

Free Carbon ◽

Graphitic Carbon ◽

Graphitic Carbon Nitride ◽

Metal Free

Download Full-text

Metal-Free Carbon Quantum Dots Implant Graphitic Carbon Nitride: Enhanced Photocatalytic Dye Wastewater Purification with Simultaneous Hydrogen Production

International Journal of Molecular Sciences ◽

10.3390/ijms21031052 ◽

2020 ◽

Vol 21 (3) ◽

pp. 1052 ◽

Cited By ~ 2

Author(s):

Lilei Zhang ◽

Jingxiao Zhang ◽

Yuanyu Xia ◽

Menghan Xun ◽

Hong Chen ◽

...

Keyword(s):

Quantum Dots ◽

Hydrogen Production ◽

Carbon Nitride ◽

Carbon Quantum Dots ◽

Free Carbon ◽

Graphitic Carbon ◽

Graphitic Carbon Nitride ◽

Dye Wastewater ◽

Wastewater Purification ◽

Metal Free

The use of photocatalysts to purify wastewater and simultaneously convert solar energy into clean hydrogen energy is of considerable significance in environmental science. However, it is still a challenge due to their relatively high costs, low efficiencies, and poor stabilities. In this study, a metal-free carbon quantum dots (CQDs) modified graphitic carbon nitride photocatalyst (CCN) was synthesized by a facile method. The characterization and theoretical calculation results reveal that the incorporation of CQDs into the g-C3N4 matrix significantly improves the charge transfer and separation efficiency, exhibits a redshift of absorption edge, narrows the bandgap, and prevents the recombination of photoexcited carriers. The hydrogen production and simultaneous degradation of methylene blue (MB) or rhodamine B (RhB) in simulated wastewaters were further tested. In the simulated wastewater, the CCN catalyst showed enhanced photodegradation efficiency, accompanied with the increased hydrogen evolution rate (1291 µmol·h−1·g−1). The internal electrical field between the g-C3N4 and the CQDs is the main reason for the spatial separation of photoexcited electron-hole pairs. Overall, this work could offer a new protocol for the design of highly efficient photocatalysts for dye wastewater purification with simultaneous hydrogen production.

Download Full-text