Engineering surface defects-rich Ti3C2 quantum dots/mesoporous C3N4 hollow nanosphere Schottky junction for efficient N2 photofixation

Author(s):  
Binbin Chang ◽  
Yanzhen Guo ◽  
Huili Liu ◽  
Li Li ◽  
Baocheng Yang

Photo-driven fixation of nitrogen (N2) to ammonia (NH3) is a kinetically complex multielectron reaction process. The key to photocatalytic N2 fixation lies in designing photocatalysts with high photoinduced carriers separation...

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4439
Author(s):  
Shui-Yang Lien ◽  
Yu-Hao Chen ◽  
Wen-Ray Chen ◽  
Chuan-Hsi Liu ◽  
Chien-Jung Huang

In this study, adding CsPbI3 quantum dots to organic perovskite methylamine lead triiodide (CH3NH3PbI3) to form a doped perovskite film filmed by different temperatures was found to effectively reduce the formation of unsaturated metal Pb. Doping a small amount of CsPbI3 quantum dots could enhance thermal stability and improve surface defects. The electron mobility of the doped film was 2.5 times higher than the pristine film. This was a major breakthrough for inorganic quantum dot doped organic perovskite thin films.


Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 419
Author(s):  
Saradh Prasad ◽  
Mamduh J. Aljaafreh ◽  
Mohamad S. AlSalhi ◽  
Abeer Alshammari

The notable photophysical characteristics of perovskite quantum dots (PQDs) (CsPbBr3) are suitable for optoelectronic devices. However, the performance of PQDs is unstable because of their surface defects. One way to address the instability is to passivate PQDs using different organic (polymers, oligomers, and dendrimers) or inorganic (ZnS, PbS) materials. In this study, we performed steady-state spectroscopic investigations to measure the photoluminescence (PL), absorption (A), transmission (T), and reflectance (R) of perovskite quantum dots (CsPbBr3) and ethylene vinyl acetate/terpene phenol (1%) (EVA-TPR (1%), or EVA) copolymer/perovskite composites in thin films with a thickness of 352 ± 5 nm. EVA is highly transparent because of its large band gap; furthermore, it is inexpensive and easy to process. However, the compatibility between PQDs and EVA should be established; therefore, a series of analyses was performed to compute parameters, such as the band gap, the coefficients of absorbance and extinction, the index of refractivity, and the dielectric constant (real and imaginary parts), from the data obtained from the above investigation. Finally, the optical conductivities of the films were studied. All these analyses showed that the EVA/PQDs were more efficient and stable both physically and optically. Hence, EVA/PQDs could become copolymer/perovskite active materials suitable for optoelectronic devices, such as solar cells and perovskite/polymer light-emitting diodes (PPLEDs).


RSC Advances ◽  
2017 ◽  
Vol 7 (6) ◽  
pp. 3072-3077 ◽  
Author(s):  
Jin Hyuck Heo ◽  
Min Hyeok Jang ◽  
Min Ho Lee ◽  
Myoung Sang You ◽  
Sang-Wook Kim ◽  
...  

We devised a straightforward spin-assisted successive precipitation and anion exchange reaction (spin-SPAER) process in order to deposit relatively uniform PbS quantum dots (QDs) on mesoporous TiO2 (mp-TiO2).


Carbon ◽  
2014 ◽  
Vol 79 ◽  
pp. 165-173 ◽  
Author(s):  
Xifang Chen ◽  
Wenxia Zhang ◽  
Qianjin Wang ◽  
Jiyang Fan

2016 ◽  
Vol 16 (4) ◽  
pp. 3592-3596 ◽  
Author(s):  
Na Jin ◽  
Hong Li ◽  
Fengyi Liu ◽  
Ya-Hong Xie

In order to increase the exchange efficiency of solar cells by down-conversion, Tb3+ doped ZnO quantum dots (QDs) were successfully synthesized by sol–gel process. The X-ray diffraction (XRD) results indicate that ZnO QDs have hexagonal wurtzite structure. ZnO QDs have a spherical shape and diameter around 5 nm, which was confirmed by high-resolution transmission electron microscopy (HRTEM). The intensity of visible light emission peaks becomes strengthened and then weakened with the increase of Tb3+ doping concentration. When the concentration is more than 1%, because of the decrease of surface defects and concentration quenching effect, the emissive intensity is weakened. The enhancement of the PL emission peaks at 542 nm, 582 nm, and 619 nm was assigned to energy transfer between Tb3+ ions and ZnO QDs host. Moreover, the absorption spectra also demonstrates energy transfers from Tb3+ ions to ZnO QDs.


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2616
Author(s):  
Liudmila Loghina ◽  
Maksym Chylii ◽  
Anastasia Kaderavkova ◽  
Stanislav Slang ◽  
Petr Svec ◽  
...  

The surface of any binary or multi-component nanocrystal has imperfections and defects. The number of surface defects depends both on the nature of the nanomaterial and on the method of its preparation. One of the possibilities to confine the number of surface defects is the epitaxial growth of the shell, which leads to a change in the physical properties while maintaining the morphology of the core. To form a shell of the desired thickness, an accurate calculation of the amount of its precursors is substantial to avoid the appearance of individual crystals consisting of the shell material. This study aimed to develop an effective calculation method for the theoretical amount of precursors required for the formation of a ZnS shell on the surface of a Cd0.25Zn0.75Se core, followed by the practical implementation of theoretical calculations and characterization of the prepared nanomaterials. This method allows the complete control of the masses and volumes of the initial reagents, which will in turn prevent undesirable nucleation of nuclei consisting of the shell material. In the synthesis of Cd0.25Zn0.75Se/ZnS core/shell quantum dots (QDs), the sources of chalcogens were substituted seleno- and thioureas, which are capable of not only supplanting modern toxic sources of sulfur and selenium but also allowing one to perform the controlled synthesis of highly photoluminescent QDs with a low number of surface defects. The result of this shell overcoating method was an impetuous augmentation in the photoluminescence quantum yield (PL QY up to 83%), uniformity in size and shape, and a high yield of nanomaterials. The developed synthetic technique of core/shell QDs provides a controlled growth of the shell on the core surface, which makes it possible to transfer this method to an industrial scale.


2016 ◽  
Vol 23 (5) ◽  
pp. 348-352 ◽  
Author(s):  
Da-Woon Jeong ◽  
◽  
Ji Young Park ◽  
Han Wook Seo ◽  
Kyoung-Mook Lim ◽  
...  

2015 ◽  
Vol 7 (6) ◽  
pp. 1065-1070
Author(s):  
Yan Chen ◽  
Naiping Wang ◽  
Chunping Li ◽  
Daguang Wang ◽  
Liang He ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document