Simultaneous layer exfoliation and defect activation in g-C3N4 nanosheets with air-water interfacial plasma: spectroscopic defect probing with tailored optical properties

被引:22
作者
Kashyap, Trishamoni [1 ,2 ]
Boruah, Palash J. [3 ]
Bailung, Heremba [3 ]
Sanyal, Dirtha [4 ]
Choudhury, Biswajit [1 ]
机构
[1] Inst Adv Study Sci & Technol, Phys Sci Div, Mat & Energy Lab, Vigyan Path 35, Guwahati, India
[2] Cotton Univ, Dept Phys, Panbazar 01, Guwahati, India
[3] Inst Adv Study Sci & Technol, Phys Sci Div, Basic & Appl Plasma Phys, Vigyan Path 35, Guwahati, India
[4] Variable Energy Cyclotron Ctr, HBNI, 1-AF Bidhannagar, Kolkata 700064, India
来源
NANOSCALE ADVANCES | 2021年 / 3卷 / 11期
关键词
GRAPHITIC CARBON NITRIDE; CYANO GROUPS; FACILE; C3N4; PERFORMANCE; ROUTE;
D O I
10.1039/d1na00098e
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Defect-activated ultrathin graphitic carbon nitride nanosheets (g-C3N4) show an enhanced visible light absorption, better charge-separation, and facile charge transport properties. These are requisites for the designing of an active photocatalyst. Conventional methods used for layer exfoliation and defect activation require strong acids, reducing agents, or ultrasonic treatment for a sufficiently long duration. Furthermore, single-step approaches for layer exfoliation and defect incorporation have hardly been reported. Herein, we have shown atmospheric plasma enabled fabrication of g-C3N4 nanosheets. This approach is simple, low-cost, less time-consuming, and a green approach to exfoliate layers and activate multiple defects concurrently. The protocol involves plasma discharging at an air-water interface at 5 kV for 30-150 min. Atomic force microscopy (AFM) reveals a layer thickness of 96.27 nm in bulk g-C3N4. The thickness becomes 3.78 nm after 150 min of plasma treatment. The exfoliated layers emerge with nitrogen-vacancy sites and self-incorporated defects as probed by positron annihilation spectroscopy (PAS) and X-ray photoelectron spectroscopy (XPS). The defect activated layers show visible light absorption extended up to 600 nm. It is demonstrated that a non-uniform change in the band gap with the plasma treatment time results from quantum confinement in thin layers and Urbach tailing due to defects acting in opposition. Further, steady-state and time-resolved spectroscopy shows the contribution of multiple defect sites for a prolonged lifetime of photoinduced carriers. These defect-activated ultrathin nanosheets of CN serve as an active photocatalyst in the degradation of rhodamine B (RhB) under white LED illumination.
引用
收藏
页码:3260 / 3271
页数:12
相关论文
共 50 条
[1]   Linker-free covalent immobilization of nisin using atmospheric pressure plasma induced grafting [J].
Aveyard, Jenny ;
Bradley, James W. ;
Mckay, Kirsty ;
McBride, Fiona ;
Donaghy, David ;
Raval, Rasmita ;
D'Sa, Raechelle A. .
JOURNAL OF MATERIALS CHEMISTRY B, 2017, 5 (13) :2500-2510
[2]   Efficient Emission Facilitated by Multiple Energy Level Transitions in Uniform Graphitic Carbon Nitride Films Deposited by Thermal Vapor Condensation [J].
Bian, Juncao ;
Li, Jianfu ;
Kalytchuk, Sergii ;
Wang, Yu ;
Li, Qian ;
Lau, Tsz Chun ;
Niehaus, Thomas A. ;
Rogach, Andrey L. ;
Zhang, Rui-Qin .
CHEMPHYSCHEM, 2015, 16 (05) :954-959
[3]   Surface Modification of C3N4 through Oxygen-Plasma Treatment: A Simple Way toward Excellent Hydrophilicity [J].
Bu, Xiuming ;
Li, Jipeng ;
Yang, Siwei ;
Sun, Jing ;
Deng, Yuan ;
Yang, Yuchen ;
Wang, Gang ;
Peng, Zheng ;
He, Peng ;
Wang, Xianying ;
Ding, Guqiao ;
Yang, Junhe ;
Xie, Xiaoming .
ACS APPLIED MATERIALS & INTERFACES, 2016, 8 (45) :31419-31425
[4]   Fe-g-C3N4-Catalyzed Oxidation of Benzene to Phenol Using Hydrogen Peroxide and Visible Light [J].
Chen, Xiufang ;
Zhang, Jinshui ;
Fu, Xianzhi ;
Antonietti, Markus ;
Wang, Xinchen .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2009, 131 (33) :11658-+
[5]   Evolution of Nitrogen-Related Defects in Graphitic Carbon Nitride Nanosheets Probed by Positron Annihilation and Photoluminescence Spectroscopy [J].
Choudhury, Biswajit ;
Paul, Kamal Kumar ;
Sanyal, Dirtha ;
Hazarika, Anil ;
Giri, P. K. .
JOURNAL OF PHYSICAL CHEMISTRY C, 2018, 122 (16) :9209-9219
[6]   Scalable and clean exfoliation of graphitic carbon nitride in NaClO solution: enriched surface active sites for enhanced photocatalytic H2 evolution [J].
Cui, Lifeng ;
Liu, Yanfei ;
Fang, Xueyou ;
Yin, Chaochuang ;
Li, Shasha ;
Sun, Di ;
Kang, Shifei .
GREEN CHEMISTRY, 2018, 20 (06) :1354-1361
[7]   Efficient synthesis of polymeric g-C3N4 layered materials as novel efficient visible light driven photocatalysts [J].
Dong, Fan ;
Wu, Liwen ;
Sun, Yanjuan ;
Fu, Min ;
Wu, Zhongbiao ;
Lee, S. C. .
JOURNAL OF MATERIALS CHEMISTRY, 2011, 21 (39) :15171-15174
[8]   A scalable chemical route to soluble acidified graphitic carbon nitride: an ideal precursor for isolated ultrathin g-C3N4 nanosheets [J].
Du, Xiaorui ;
Zou, Guojun ;
Wang, Zhonghao ;
Wang, Xiaolai .
NANOSCALE, 2015, 7 (19) :8701-8706
[9]   Dimension-dependent band alignment and excitonic effects in graphitic carbon nitride: a many-body perturbation and time-dependent density functional theory study [J].
Espinosa-Garcia, W. F. ;
Osorio-Guillen, J. M. ;
Araujo, C. Moyses .
RSC ADVANCES, 2017, 7 (71) :44997-45002
[10]   Structural Investigation of Graphitic Carbon Nitride via XRD and Neutron Diffraction [J].
Fina, Federica ;
Callear, Samantha K. ;
Carins, George M. ;
Irvine, John T. S. .
CHEMISTRY OF MATERIALS, 2015, 27 (07) :2612-2618