Photocatalytic Activity of Phosphorus and Nitrogen Co-Doped Carbon Quantum Dots/TiO2 Nanosheets

NANO ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. 2050151
Author(s):  
Kailai Liu ◽  
Fanmin Kong ◽  
Chaoqun Zhu ◽  
Guodong Jiang
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Uv Light ◽  
Kinetic Constant ◽  
Synthesis Method ◽  
Carbon Quantum Dots ◽  
Active Species ◽  
Doping Amount ◽  
Tio2 Nanosheets ◽  
Co Doped

Double element co-doped carbon quantum dots (CQDs) have unique electron properties and broad prospects in photocatalysis. In this paper, the phosphorus and nitrogen co-doped CQDs (PNCQDs) were loaded on TiO2 nanosheets by in-situ synthesis method. Physical structure and chemical composition of samples were analyzed by XRD, FT-IR, XPS, SEM and TEM. UV–Vis spectra show the donor–acceptor coupling between PNCQDs and TiO2 and enhanced strong UV light absorption. Photoluminescence spectra indicate that PNCQDs effectively promote charge separation, which is different from nitrogen doped CQDs. The sample 1-PNCT with the optimal phosphorus doping amount has the highest kinetic constant for photodegradation of Methylene Blue (MB), which is 3.4 times pure TiO2. A possible Z-scheme photodegradation mechanism is proposed according to the active species scavenge experiment results in which PNCQDs can not only accept but also localize photogenerated electrons to dopant sites due to the quantum wells created by P and N doping energy barriers.

scholarly journals Formation of Carbon Quantum Dots via Hydrothermal Carbonization: Investigate the Effect of Precursors

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 986
Author(s):  
Md Rifat Hasan ◽  
Nepu Saha ◽  
Thomas Quaid ◽  
M. Toufiq Reza
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Microcrystalline Cellulose ◽  
Uv Light ◽  
Synthesis Method ◽  
Hydrothermal Carbonization ◽  
Carbon Quantum Dots ◽  
Medical Diagnostics ◽  
Particle Size Range ◽  
Wide Range

Carbon quantum dots (CQDs) are nanomaterials with a particle size range of 2 to 10 nm. CQDs have a wide range of applications such as medical diagnostics, bio-imaging, biosensors, coatings, solar cells, and photocatalysis. Although the effect of various experimental parameters, such as the synthesis method, reaction time, etc., have been investigated, the effect of different feedstocks on CQDs has not been studied yet. In this study, CQDs were synthesized from hydroxymethylfurfural, furfural, and microcrystalline cellulose via hydrothermal carbonization at 220 °C for 30 min of residence time. The produced CQDs showed green luminescence behavior under the short-wavelength UV light. Furthermore, the optical properties of CQDs were investigated using ultraviolet-visible spectroscopy and emission spectrophotometer, while the morphology and chemical bonds of CQDs were investigated using transmission electron microscopy and Fourier-transform infrared spectroscopy, respectively. Results showed that all CQDs produced from various precursors have absorption and emission properties but these optical properties are highly dependent on the type of precursor. For instance, the mean particle sizes were 6.36 ± 0.54, 5.35 ± 0.56, and 3.94 ± 0.60 nm for the synthesized CQDs from microcrystalline cellulose, hydroxymethylfurfural, and furfural, respectively, which appeared to have similar trends in emission intensities. In addition, the synthesized CQDs experienced different functionality (e.g., C=O, O-H, C-O) resulting in different absorption behavior.

scholarly journals Recent Advancements in Doped/Co-Doped Carbon Quantum Dots for Multi-Potential Applications

2019 ◽  
Vol 5 (2) ◽  
pp. 24 ◽  
Author(s):  
Ganeshlenin Kandasamy
Keyword(s):  
Quantum Dots ◽  
Optical Sensors ◽  
Carbon Nanomaterials ◽  
Synthesis Method ◽  
Carbon Quantum Dots ◽  
Carbon Nanodots ◽  
Synthesis Methods ◽  
Sensing Applications ◽  
Potential Applications ◽  
Co Doped

Carbon quantum dots (CQDs)/carbon nanodots are a new class of fluorescent carbon nanomaterials having an approximate size in the range of 2–10 nm. The majority of the reported review articles have discussed about the development of the CQDs (via simple and cost-effective synthesis methods) for use in bio-imaging and chemical-/biological-sensing applications. However, there is a severe lack of consolidated studies on the recently developed CQDs (especially doped/co-doped) that are utilized in different areas of application. Hence, in this review, we have extensively discussed about the recent development in doped and co-doped CQDs (using elements/heteroatoms—e.g., boron (B), fluorine (F), nitrogen (N), sulphur (S), and phosphorous (P)), along with their synthesis method, reaction conditions, and/or quantum yield (QY), and their emerging multi-potential applications including electrical/electronics (such as light emitting diode (LED) and solar cells), fluorescent ink for anti-counterfeiting, optical sensors (for detection of metal ions, drugs, and pesticides/fungicides), gene delivery, and temperature probing.

scholarly journals Exploring the role of triazole functionalized heteroatom co-doped carbon quantum dots against human coronaviruses

Nano Today ◽  
2020 ◽  
Vol 35 ◽  
pp. 101001 ◽  
Author(s):  
Piyush Garg ◽  
Sujata Sangam ◽  
Dakshi Kochhar ◽  
Siddhartha Pahari ◽  
Chirantan Kar ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Quantum Dots ◽  
Human Coronaviruses ◽  
Co Doped

Enhancement of lignin-based carbon quantum dots from poplar pre-hydrolysis liquor on photocatalytic CO2 reduction via TiO2 nanosheets

2020 ◽  
pp. 113161
Author(s):  
Qichao Gao ◽  
Zhimin Yuan ◽  
Guihua Yang ◽  
Zhongjian Tian ◽  
Zaiyong Jiang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Co2 Reduction ◽  
Carbon Quantum Dots ◽  
Tio2 Nanosheets

Nitrogen and sulfur co-doped chiral carbon quantum dots with independent photoluminescence and chirality

2017 ◽  
Vol 4 (6) ◽  
pp. 946-953 ◽  
Author(s):  
Lulu Hu ◽  
Yue Sun ◽  
Yunjie Zhou ◽  
Liang Bai ◽  
Yalin Zhang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Carbon Quantum Dots ◽  
Chiral Carbon ◽  
Recognition Ability ◽  
Electrochemical Recognition ◽  
Co Doped

Chiral CQDs exhibit strong PL and outstanding enantioselective electrochemical recognition ability. Moreover, chiral CQDs possess independent PL and chiral properties.

scholarly journals Synthesis of Pyridinic-Rich N, S Co-doped Carbon Quantum Dots as Effective Enzyme Mimics

2017 ◽  
Vol 12 (1) ◽  
Author(s):  
Teng Liu ◽  
Zhi-wei Cui ◽  
Jun Zhou ◽  
Ying Wang ◽  
Zhi-gang Zou
Keyword(s):  
Quantum Dots ◽  
Carbon Quantum Dots ◽  
Enzyme Mimics ◽  
Co Doped
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