scholarly journals Assembly of CaIn2S4 on Defect-Rich BiOCl for Acceleration of Interfacial Charge Separation and Photocatalytic Phenol Degradation via S-Scheme Electron Transfer Mechanism

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1130
Author(s):  
Zhuangzhuang Zhang ◽  
Yuanyuan Zhang ◽  
Xuanxuan Han ◽  
Li Guo ◽  
Danjun Wang ◽  
...  
Keyword(s):  
Charge Separation ◽  
Environmental Remediation ◽  
Oxygen Vacancies ◽  
Phenol Degradation ◽  
Superior Performance ◽  
The Novel ◽  
Electron Transfer Mechanism ◽  
Synthetic Strategy ◽  
Interfacial Charge ◽  
High Temperature Calcination

The novel 2D/2D S-scheme heterostructure of BiOCl nanosheets coupled with CaIn2S4 nanosheets (CaIn2S4/BiOCl-SOVs), which contains surface oxygen vacancies (SOVs), has been successfully prepared by high-temperature calcination combined with a solvothermal synthetic strategy. Under visible-light irradiation, the apparent rate constant (Kapp/mim−1) for phenol degradation on the 1 wt% CaIn2S4/BiOCl-SOVs photocatalyst is about 32.8 times higher than that of pure BiOCl. The superior performance was attributed to the synergistic effect between the SOVs, CaIn2S4, and BiOCl, which can effectively narrow the bandgap and accelerate the interfacial charge separation of CaIn2S4/BiOCl-SOVs heterojunctions. Subsequently, it significantly promotes the generation of superoxide radicals (O2−), hydroxyl radicals, and h+, which participate in the photodegradation process of phenol. The catalyst still maintained a relatively high activity after repeated tests as a demonstration of its photostability. This work successfully proposed an efficient method to design a new 2D/2D S-scheme heterostructure with SOVs as possible photocatalysts in the field of environmental remediation.

scholarly journals Oxide-based catalysis: tailoring surface structures via organic ligands and related interfacial charge carrier for environmental remediation

RSC Advances ◽  
2021 ◽  
Vol 11 (31) ◽  
pp. 19059-19069
Author(s):  
S. Harish ◽  
S. Athithya ◽  
V. Shivani ◽  
S. Ponnusamy ◽  
M. Shimomura ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Structure Formation ◽  
Environmental Remediation ◽  
Organic Ligands ◽  
Surface Structures ◽  
Hierarchical Nanostructures ◽  
Amine Ligands ◽  
Interfacial Charge ◽  
Photocatalytic Applications

Hierarchical nanostructures of ZnO/CuO and the effects of amine ligands on their structure, formation and photocatalytic applications were investigated.

scholarly journals MXene-Ti3C2 assisted one-step synthesis of carbon-supported TiO2/Bi4NbO8Cl heterostructures for enhanced photocatalytic water decontamination

Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 2077-2088 ◽  
Author(s):  
Daixun Jiang ◽  
Xun Sun ◽  
Xilu Wu ◽  
Shuai Zhang ◽  
Xiaofei Qu ◽  
...  
Keyword(s):  
Charge Separation ◽  
Photocatalytic Performance ◽  
Separation Efficiency ◽  
Salt Flux ◽  
The Novel ◽  
Water Contaminants ◽  
Photocatalytic Removal ◽  
One Step ◽  
Charge Separation Efficiency ◽  
Perovskite Type

AbstractThe strategy to improve the photocatalytic removal efficiencies towards organic pollutants is still a challenge for the novel Sillen–Aurivillius perovskite type Bi4NbO8Cl. Herein, we report carbon-supported TiO2/Bi4NbO8Cl (C-TiO2/Bi4NbO8Cl) heterostructures with enhanced charge separation efficiency, which were fabricated via molten-salt flux process. The carbon-supported TiO2 particles were derived from MXene Ti3C2 precursors, and attached on plate-like Bi4NbO8Cl, acting as electron-traps to achieve supressed recombination of photo-induced charges. The improved charge separation confers C-TiO2/Bi4NbO8Cl heterostructures superior photocatalytic performance with 53% higher than pristine Bi4NbO8Cl, towards rhodamine B removal with the help of photo-induced holes. Moreover, the C-TiO2/Bi4NbO8Cl heterostructures can be expanded to deal with other water contaminants, such as methyl orange, ciprofloxacin and 2,4-dichlorophenol with 44, 25 and 13% promotion, respectively, and thus the study offers a series of efficient photocatalysts for water purification.

scholarly journals Long-lived charge separation following pump-wavelength–dependent ultrafast charge transfer in graphene/WS2 heterostructures

2021 ◽  
Vol 7 (9) ◽  
pp. eabd9061
Author(s):  
Shuai Fu ◽  
Indy du Fossé ◽  
Xiaoyu Jia ◽  
Jingyin Xu ◽  
Xiaoqing Yu ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Charge Separation ◽  
Transient Absorption ◽  
Transition Metal Dichalcogenides ◽  
Thermionic Emission ◽  
Great Promise ◽  
Metal Dichalcogenides ◽  
Ultrafast Charge Transfer ◽  
Device Operation ◽  
Interfacial Charge

Van der Waals heterostructures consisting of graphene and transition metal dichalcogenides have shown great promise for optoelectronic applications. However, an in-depth understanding of the critical processes for device operation, namely, interfacial charge transfer (CT) and recombination, has so far remained elusive. Here, we investigate these processes in graphene-WS2 heterostructures by complementarily probing the ultrafast terahertz photoconductivity in graphene and the transient absorption dynamics in WS2 following photoexcitation. We observe that separated charges in the heterostructure following CT live extremely long: beyond 1 ns, in contrast to ~1 ps charge separation reported in previous studies. This leads to efficient photogating of graphene. Furthermore, for the CT process across graphene-WS2 interfaces, we find that it occurs via photo-thermionic emission for sub-A-exciton excitations and direct hole transfer from WS2 to the valence band of graphene for above-A-exciton excitations. These findings provide insights to further optimize the performance of optoelectronic devices, in particular photodetection.

Oxygen vacancies boosted charge separation towards enhanced photodegradation ability over 3D/2D Z-scheme BiO1−XBr/Fe2O3 heterostructures

2021 ◽  
Vol 269 ◽  
pp. 118693
Author(s):  
Wenli Zhao ◽  
Wenliang Wang ◽  
Tongyu Han ◽  
Hongtao Wang ◽  
Haochun Zhang ◽  
...  
Keyword(s):  
Charge Separation ◽  
Oxygen Vacancies

scholarly journals Water Splitting: In Situ Formation of Oxygen Vacancies Achieving Near‐Complete Charge Separation in Planar BiVO 4 Photoanodes (Adv. Mater. 26/2020)

2020 ◽  
Vol 32 (26) ◽  
pp. 2070198 ◽  
Author(s):  
Songcan Wang ◽  
Tianwei He ◽  
Peng Chen ◽  
Aijun Du ◽  
Kostya (Ken) Ostrikov ◽  
...  
Keyword(s):  
Water Splitting ◽  
Charge Separation ◽  
Oxygen Vacancies ◽  
In Situ Formation

scholarly journals Human Consensus-Oriented Image Captioning

2020 ◽  
Author(s):  
Ziwei Wang ◽  
Zi Huang ◽  
Yadan Luo
Keyword(s):  
Data Quality ◽  
Ground Truth ◽  
Superior Performance ◽  
The Novel ◽  
Image Captioning ◽  
Visual Objects ◽  
Grammatical Errors ◽  
Wrong Identification ◽  
Model Training ◽  
Treat All

Image captioning aims to describe an image with a concise, accurate, and interesting sentence. To build such an automatic neural captioner, the traditional models align the generated words with a number of human-annotated sentences to mimic human-like captions. However, the crowd-sourced annotations inevitably come with data quality issues such as grammatical errors, wrong identification of visual objects and sub-optimal sentence focus. During the model training, existing methods treat all the annotations equally regardless of the data quality. In this work, we explicitly engage human consensus to measure the quality of ground truth captions in advance, and directly encourage the model to learn high quality captions with high priority. Therefore, the proposed consensus-oriented method can accelerate the training process and achieve superior performance with only supervised objective without time-consuming reinforcement learning. The novel consensus loss can be implemented into most of the existing state-of-the-art methods, boosting the BLEU-4 performance by maximum relative 12.47% comparing to the conventional cross-entropy loss. Extensive experiments are conducted on MS-COCO Image Captioning dataset demonstrating the proposed human consensus-oriented training method can significantly improve the training efficiency and model effectiveness.

scholarly journals Three‐in‐One Oxygen Vacancies: Whole Visible‐Spectrum Absorption, Efficient Charge Separation, and Surface Site Activation for Robust CO 2 Photoreduction

2019 ◽  
Vol 131 (12) ◽  
pp. 3920-3924 ◽  
Author(s):  
Hongjian Yu ◽  
Jieyuan Li ◽  
Yihe Zhang ◽  
Songqiu Yang ◽  
Keli Han ◽  
...  
Keyword(s):  
Charge Separation ◽  
Oxygen Vacancies ◽  
Visible Spectrum ◽  
Surface Site ◽  
Efficient Charge

scholarly journals A Novel Massive Deployment Solution Based on the Peer-to-Peer Protocol

2019 ◽  
Vol 9 (2) ◽  
pp. 296 ◽  
Author(s):  
Steven J. H. Shiau ◽  
Yu-Chiang Huang ◽  
Ching-Hsuan Yen ◽  
Yu-Chin Tsai ◽  
Chen-Kai Sun ◽  
...  
Keyword(s):  
File System ◽  
File Systems ◽  
Peer To Peer ◽  
Superior Performance ◽  
The Novel ◽  
Storage Space ◽  
Improve Performance ◽  
Temporary Storage ◽  
P2p File Sharing ◽  
System Versus

: The BitTorrent (BT) is a peer-to-peer (P2P) file sharing protocol that was developed approximately 20 years ago, is becoming increasingly popular, and has been widely accepted. The BT-based mass deployment system can be used to improve performance and scalability that cannot be achieved by the unicasting, broadcasting, and multicasting protocols. However, when the BT-based system is applied in massive deployments, a major issue related to insufficient temporary storage space to store the whole system image before deploying needs to be resolved. Such problems arose because the system is deployed to the disk space, meaning that it cannot be used for temporary storage. Therefore, a novel BT-based solution that can remove the limitations caused by the insufficient temporary storage issue is proposed. The BT-based mass deployment system was designed by using the file system blocks transferring (FSBT) mechanism. The receiver of the FSBT mechanism can obtain the blocks of the file system from other peers. Then, those blocks will be written directly to raw disks or partitions. The sender of the FSBT mechanism can read the blocks of file systems directly from raw disks or partitions. Then, the blocks can be sent to other peers. This approach solves the insufficient temporary storage issue. The novel BT-based mass deployment system was tested and verified for the configuration consisting of at most 32 personal computers (PCs). To demonstrate the achievable performance of the novel BT-based system, comparisons were made between the novel program and the traditional multicast solutions, as well as other solutions for mass deployment. The proposed BT solution can be much faster than the multicast solution when deploying 11 machines or more. The experimental results demonstrated the feasibility and superior performance of the proposed system. Furthermore, performance comparisons of the proposed BT-based mass deployment system versus other solutions demonstrated the feasibility and efficiency of the proposed solution. In the future, the BT parameters can be further optimized, and the simultaneous read and write features can be implemented to improve the deployment performance. In addition, the BT-based mass deployment system can serve as the basis for the development of other mass deployment systems.

Sign in / Sign up

Export Citation Format

Share Document