scholarly journals Metal/Semiconductor Nanocomposites for Photocatalysis: Fundamentals, Structures, Applications and Properties

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 359 ◽  
Author(s):  
Yong-sheng Fu ◽  
Jun Li ◽  
Jianguo Li
Keyword(s):  
Surface Plasmon Resonance ◽  
Future Development ◽  
Charge Separation ◽  
Environmental Remediation ◽  
High Performance ◽  
Green Technology ◽  
Human Society ◽  
Semiconductor Interface ◽  
Semiconductor Nanocomposites ◽  
Synthetic Approaches

Due to the capability of utilizing light energy to drive chemical reactions, photocatalysis has been widely accepted as a green technology to help us address the increasingly severe environment and energy issues facing human society. To date, a large amount of research has been devoted to enhancing the properties of photocatalysts. As reported, coupling semiconductors with metals is one of the most effective methods to achieve high-performance photocatalysts. The excellent properties of metal/semiconductor (M/S) nanocomposite photocatalysts originate in two aspects: (i) improved charge separation at the metal-semiconductor interface; and (ii) increased absorption of visible light due to the surface plasmon resonance of metals. So far, many M/S nanocomposite photocatalysts with different structures have been developed for the application in environmental remediation, selective organic transformation, hydrogen evolution, and disinfection. Herein, we will give a review on the M/S nanocomposite photocatalysts, regarding their fundamentals, structures (as well as their typical synthetic approaches), applications and properties. Finally, we will also present our perspective on the future development of M/S nanocomposite photocatalysts.

scholarly journals SnS2/TiO2 Nanocomposites for Hydrogen Production and Photodegradation Under Extended Solar Irradiation

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 589
Author(s):  
Sivagowri Shanmugaratnam ◽  
Balaranjan Selvaratnam ◽  
Aravind Baride ◽  
Ranjit Koodali ◽  
Punniamoorthy Ravirajan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Hydrogen Evolution ◽  
Environmental Remediation ◽  
High Performance ◽  
Degradation Mechanism ◽  
Solar Irradiation ◽  
Earth Abundant ◽  
Improved Performance ◽  
Chalcogenide Materials

Earth–abundant transition metal chalcogenide materials are of great research interest for energy production and environmental remediation, as they exhibit better photocatalytic activity due to their suitable electronic and optical properties. This study focuses on the photocatalytic activity of flower-like SnS2 nanoparticles (composed of nanosheet subunits) embedded in TiO2 synthesized by a facile hydrothermal method. The materials were characterized using different techniques, and their photocatalytic activity was assessed for hydrogen evolution reaction and the degradation of methylene blue. Among the catalysts studied, 10 wt. % of SnS2 loaded TiO2 nanocomposite shows an optimum hydrogen evolution rate of 195.55 µmolg−1, whereas 15 wt. % loading of SnS2 on TiO2 exhibits better performance against the degradation of methylene blue (MB) with the rate constant of 4.415 × 10−4 s−1 under solar simulated irradiation. The improved performance of these materials can be attributed to the effective photo-induced charge transfer and reduced recombination, which make these nanocomposite materials promising candidates for the development of high-performance next-generation photocatalyst materials. Further, scavenging experiments were carried out to confirm the reactive oxygen species (ROS) involved in the photocatalytic degradation. It can be observed that there was a 78% reduction in the rate of degradation when IPA was used as the scavenger, whereas around 95% reduction was attained while N2 was used as the scavenger. Notably, very low degradation (<5%) was attained when the dye alone was directly under solar irradiation. These results further validate that the •OH radical and the superoxide radicals can be acknowledged for the degradation mechanism of MB, and the enhancement of degradation efficiency may be due to the combined effect of in situ dye sensitization during the catalysis and the impregnation of low bandgap materials on TiO2.

Inductive Effect as a Universal Concept to Design Efficient Catalysts for CO2 Electrochemical Reduction: Electronegativity Difference Makes Difference

2021 ◽  
Author(s):  
Huihuang Chen ◽  
Weng Fu ◽  
Zhigang Geng ◽  
Jie Zeng ◽  
Bo Yang
Keyword(s):  
Electrochemical Reduction ◽  
Energy Supply ◽  
Environmental Remediation ◽  
High Performance ◽  
Inductive Effect ◽  
Great Promise ◽  
Electronegativity Difference

CO2 electrochemical reduction (CO2ER) into valuable chemical feedstocks holds great promise for energy supply and environmental remediation but remains a challenge due to the lack of high-performance electrocatalysts. Inductive effect,...

scholarly journals Carbon Nanodots as a Potential Transport Layer for Boosting Performance of All-Inorganic Perovskite Nanocrystals-based Photodetector

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 717
Author(s):  
Hassan Algadi ◽  
Ahmad Umar ◽  
Hasan Albargi ◽  
Turki Alsuwian ◽  
Sotirios Baskoutas
Keyword(s):  
Charge Separation ◽  
High Performance ◽  
Band Alignment ◽  
Transport Layer ◽  
Carbon Nanodots ◽  
Separation Mechanism ◽  
Perovskite Layer ◽  
Inorganic Perovskite ◽  
Highly Efficient ◽  
Efficient Charge

A low-cost and simple drop-casting method was used to fabricate a carbon nanodot (C-dot)/all-inorganic perovskite (CsPbBr3) nanosheet bilayer heterojunction photodetector on a SiO2/Si substrate. The C-dot/perovskite bilayer heterojunction photodetector shows a high performance with a responsivity (R) of 1.09 A/W, almost five times higher than that of a CsPbBr3-based photodetector (0.21 A/W). In addition, the hybrid photodetector exhibits a fast response speed of 1.318/1.342 µs and a highly stable photocurrent of 6.97 µA at 10 V bias voltage. These figures of merits are comparable with, or much better than, most reported perovskite heterojunction photodetectors. UV–Vis absorption and photoluminescent spectra measurements reveal that the C-dot/perovskite bilayer heterojunction has a band gap similar to the pure perovskite layer, confirming that the absorption and emission in the bilayer heterojunction is dominated by the top layer of the perovskite. Moreover, the emission intensity of the C-dot/perovskite bilayer heterojunction is less than that of the pure perovskite layer, indicating that a significant number of charges were extracted by the C-dot layer. The studied band alignment of the C-dots and perovskites in the dark and under emission reveals that the photodetector has a highly efficient charge separation mechanism at the C-dot/perovskite interface, where the recombination rate between photogenerated electrons and holes is significantly reduced. This highly efficient charge separation mechanism is the main reason behind the enhanced performance of the C-dot/perovskite bilayer heterojunction photodetector.

Persistent memory hash indexes

2021 ◽  
Vol 14 (5) ◽  
pp. 785-798
Author(s):  
Daokun Hu ◽  
Zhiwen Chen ◽  
Jianbing Wu ◽  
Jianhua Sun ◽  
Hao Chen
Keyword(s):  
Future Development ◽  
High Performance ◽  
Performance Metrics ◽  
Comprehensive Evaluation ◽  
State Of The Art ◽  
Hash Tables ◽  
Trade Offs ◽  
Depth Analysis ◽  
Persistent Memory ◽  
Memory Modules

Persistent memory (PM) is increasingly being leveraged to build hash-based indexing structures featuring cheap persistence, high performance, and instant recovery, especially with the recent release of Intel Optane DC Persistent Memory Modules. However, most of them are evaluated on DRAM-based emulators with unreal assumptions, or focus on the evaluation of specific metrics with important properties sidestepped. Thus, it is essential to understand how well the proposed hash indexes perform on real PM and how they differentiate from each other if a wider range of performance metrics are considered. To this end, this paper provides a comprehensive evaluation of persistent hash tables. In particular, we focus on the evaluation of six state-of-the-art hash tables including Level hashing, CCEH, Dash, PCLHT, Clevel, and SOFT, with real PM hardware. Our evaluation was conducted using a unified benchmarking framework and representative workloads. Besides characterizing common performance properties, we also explore how hardware configurations (such as PM bandwidth, CPU instructions, and NUMA) affect the performance of PM-based hash tables. With our in-depth analysis, we identify design trade-offs and good paradigms in prior arts, and suggest desirable optimizations and directions for the future development of PM-based hash tables.

V-rich Bi2S3 nanowire with efficient charge separation and transport for high-performance and robust photoelectrochemical application under visible light

2020 ◽  
Vol 350 ◽  
pp. 47-55
Author(s):  
Yuan-Yuan Geng ◽  
Chun-Lan Tao ◽  
Shi-Fang Duan ◽  
Jovan San Martin ◽  
Yixiong Lin ◽  
...  
Keyword(s):  
Visible Light ◽  
Charge Separation ◽  
High Performance ◽  
Efficient Charge

scholarly journals Nanotechnological Advances in Catalytic Thin Films for Green Large-Area Surfaces

2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
Suzan Biran Ay ◽  
Nihan Kosku Perkgoz
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Environmental Remediation ◽  
Transformational Change ◽  
Green Technology ◽  
Large Area ◽  
Thin Film Coatings ◽  
Technology Applications ◽  
Production Techniques ◽  
Save Energy

Large-area catalytic thin films offer great potential for green technology applications in order to save energy, combat pollution, and reduce global warming. These films, either embedded with nanoparticles, shaped with nanostructuring techniques, hybridized with other systems, or functionalized with bionanotechnological methods, can include many different surface properties including photocatalytic, antifouling, abrasion resistant and mechanically resistive, self-cleaning, antibacterial, hydrophobic, and oleophobic features. Thus, surface functionalization with such advanced structuring methods is of significance to increase the performance and wide usage of large-area thin film coatings specifically for environmental remediation. In this review, we focus on methods to increase the efficiency of catalytic reactions in thin film and hence improve the performance in relevant applications while eliminating high cost with the purpose of widespread usage. However, we also include the most recent hybrid architectures, which have potential to make a transformational change in surface applications as soon as high quality and large area production techniques are available. Hence, we present and discuss research studies regarding both organic and inorganic methods that are used to structure thin films that have potential for large-area and eco-friendly coatings.

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