scholarly journals Morphology-Governed Performance of Plasmonic Photocatalysts

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1070 ◽  
Author(s):  
Zhishun Wei ◽  
Marcin Janczarek ◽  
Kunlei Wang ◽  
Shuaizhi Zheng ◽  
Ewa Kowalska

Plasmonic photocatalysts have been extensively studied for the past decade as a possible solution to energy crisis and environmental problems. Although various reports on plasmonic photocatalysts have been published, including synthesis methods, applications, and mechanism clarifications, the quantum yields of photochemical reactions are usually too low for commercialization. Accordingly, it has been proposed that preparation of plasmonic photocatalysts with efficient light harvesting and inhibition of charge carriers’ recombination might result in improvement of photocatalytic activity. Among various strategies, nano-architecture of plasmonic photocatalysts seems to be one of the best strategies, including the design of properties for both semiconductor and noble-metal-deposits, as well as the interactions between them. For example, faceted nanoparticles, nanotubes, aerogels, and super-nano structures of semiconductors have shown the improvement of photocatalytic activity and stability. Moreover, the selective deposition of noble metals on some parts of semiconductor nanostructures (e.g., specific facets, basal or lateral surfaces) results in an activity increase. Additionally, mono-, bi-, and ternary-metal-modifications have been proposed as the other ways of performance improvement. However, in some cases, the interactions between different noble metals might cause unwanted charge carriers’ recombination. Accordingly, this review discusses the recent strategies on the improvements of the photocatalytic performance of plasmonic photocatalysts.

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Giyaullah Habibullah ◽  
Jitka Viktorova ◽  
Tomas Ruml

AbstractNoble metals have played an integral part in human history for centuries; however, their integration with recent advances in nanotechnology and material sciences have provided new research opportunities in both academia and industry, which has resulted in a new array of advanced applications, including medical ones. Noble metal nanoparticles (NMNPs) have been of great importance in the field of biomedicine over the past few decades due to their importance in personalized healthcare and diagnostics. In particular, platinum, gold and silver nanoparticles have achieved the most dominant spot in the list, thanks to a very diverse range of industrial applications, including biomedical ones such as antimicrobial and antiviral agents, diagnostics, drug carriers and imaging probes. In particular, their superior resistance to extreme conditions of corrosion and oxidation is highly appreciated. Notably, in the past two decades there has been a tremendous advancement in the development of new strategies of more cost-effective and robust NMNP synthesis methods that provide materials with highly tunable physicochemical, optical and thermal properties, and biochemical functionalities. As a result, new advanced hybrid NMNPs with polymer, graphene, carbon nanotubes, quantum dots and core–shell systems have been developed with even more enhanced physicochemical characteristics that has led to exceptional diagnostic and therapeutic applications. In this review, we aim to summarize current advances in the synthesis of NMNPs (Au, Ag and Pt).


Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 827 ◽  
Author(s):  
Tharishinny Raja-Mogan ◽  
Bunsho Ohtani ◽  
Ewa Kowalska

Noble metal (NM)-modified wide-bandgap semiconductors with activity under visible light (Vis) irradiation, due to localized surface plasmon resonance (LSPR), known as plasmonic photocatalysts, have been intensively studied over the last few years. Despite the novelty of the topic, a large number of reports have already been published, discussing the optimal properties, synthesis methods and mechanism clarification. It has been proposed that both efficient light harvesting and charge carriers’ migration are detrimental for high and stable activity under Vis irradiation. Accordingly, photonic crystals (PCs) with photonic bandgap (PBG) and slow photon effects seem to be highly attractive for efficient use of incident photons. Therefore, the study on PCs-based plasmonic photocatalysts has been conducted, mainly on titania inverse opal (IO) modified with nanoparticles (NPs) of NM. Although, the research is quite new and only several reports have been published, it might be concluded that the matching between LSPR and PBG (especially at red edge) by tuning of NMNPs size and IO-void diameter, respectively, is the most crucial for the photocatalytic activity.


Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1111 ◽  
Author(s):  
A.B. Dongil

This short review aims at providing an overview of the most recent literature regarding transition metal nitrides (TMN) applied in heterogeneous catalysis. These materials have received renewed attention in the last decade due to its potential to substitute noble metals mainly in biomass and energy transformations, the decomposition of ammonia being one of the most studied reactions. The reactions considered in this review are limited to thermal catalysis. However the potential of these materials spreads to other key applications as photo- and electrocatalysis in hydrogen and oxygen evolution reactions. Mono, binary and exceptionally ternary metal nitrides have been synthetized and evaluated as catalysts and, in some cases, promoters are added to the structure in an attempt to improve their catalytic performance. The objective of the latest research is finding new synthesis methods that allow to obtain smaller metal nanoparticles and increase the surface area to improve their activity, selectivity and stability under reaction conditions. After a brief introduction and description of the most employed synthetic methods, the review has been divided in the application of transition metal nitrides in the following reactions: hydrotreatment, oxidation and ammonia synthesis and decomposition.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1985
Author(s):  
Irina Plesco ◽  
Vladimir Ciobanu ◽  
Tudor Braniste ◽  
Veaceslav Ursaki ◽  
Florian Rasch ◽  
...  

A new type of photocatalyst is proposed on the basis of aero-β-Ga2O3, which is a material constructed from a network of interconnected tetrapods with arms in the form of microtubes with nanometric walls. The aero-Ga2O3 material is obtained by annealing of aero-GaN fabricated by epitaxial growth on ZnO microtetrapods. The hybrid structures composed of aero-Ga2O3 functionalized with Au or Pt nanodots were tested for the photocatalytic degradation of methylene blue dye under UV or visible light illumination. The functionalization of aero-Ga2O3 with noble metals results in the enhancement of the photocatalytic performances of bare material, reaching the performances inherent to ZnO while gaining the advantage of the increased chemical stability. The mechanisms of enhancement of the photocatalytic properties by activating aero-Ga2O3 with noble metals are discussed to elucidate their potential for environmental applications.


Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 255
Author(s):  
Dien-Thien To ◽  
Yu-Chuan Lin

Copper phyllosilicates-derived catalysts (CuPS-cats) have been intensively explored in the past two decades due to their promising activity in carbonyls hydrogenation. However, CuPS-cats have not been completely reviewed. This paper focuses on the aspects concerning CuPS-cats from synthesis methods, effects of preparation conditions, and dopant to catalytic applications of CuPS-cats. The applications of CuPS-cats include the hydrogenation of carboxylates, carboxylic acids, carbonates, formyls, and CO2 to their respective alcohols. Besides, important factors such as the Cu dispersion, Cu+ and Cu0 surface areas, particles size, interaction between Cu and supports and dopants, morphologies, and spatial effect on catalytic performance of CuPS-cats are discussed. The deactivation and remedial actions to improve the stability of CuPS-cats are summarized. It ends up with the challenges and prospective by using this type of catalyst.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Chunlong Li ◽  
Jie Li ◽  
Zhengping Li ◽  
Huayong Zhang ◽  
Yangyang Dang ◽  
...  

Nanostructured halide perovskites have highly yielded record LEDs due to their higher versatility in the local management of charge carriers, which has enabled photoluminescence quantum yields (PLQYs) close to 100%....


2021 ◽  
Vol 02 ◽  
Author(s):  
Larissa Bach-Toledo ◽  
Patricio G. Peralta-Zamora ◽  
Liziê Daniela Tentler Prola

Background: The demand for photocatalytic processes assisted by solar radiation has stimulated the upgrading of established systems, as the semiconductor modification with noble metals. Objective: the synthesis, characterization, and photocatalytic activity evaluation of the Ag-TiO2, against sulfamethoxazole molecule, and investigate the significance of the plasmonic phenomenon in Visible (450 - 1000nm) and UV-Vis (315-800 nm) radiation. Methods: Different nanocomposites Ag/TiO2 ratios were synthesized by the deposition of Ag nanoparticles on the TiO2 surface by in-situ photoreduction, and then calcinated at 400°C for 2 hr. The chemical-physical properties of the materials were examined by UV-Vis Diffuse Reflectance (UV-Vis DRS) Scanning Electronic Microscopy (SEM), Transmission Electronic Microscopy (TEM), X-Ray Energy Dispersive Spectroscopy (EDS). The experiments were conducted in a cooled photochemical reactor irradiated by halogen lamp (250W). The degradation of Sulfamethoxazole was monitored by HPLC-DAD. Results: Although the prepared photocatalysts show an intense plasmonic band centered at 500 nm, no photocatalytic activity was observed in the process assisted by artificial visible radiation ( ≥ 450 nm). In processes assisted by artificial UV-Vis radiation, the photolysis rate of the model compound (sulfamethoxazole) was higher than the photocatalytic rate, and in the absence of UV radiation, all the reactions were inhibited. The positive effect of the presence of silver nanoparticles onto the TiO2 surface was only evidenced in studies involving solar radiation. Conclusion: The results suggest the need for a balance between UV and Vis radiation to activate the nanocomposite and perform the sulfamethoxazole degradation.


NANO ◽  
2016 ◽  
Vol 11 (05) ◽  
pp. 1650054 ◽  
Author(s):  
Bin Zeng ◽  
Yang Yin

CuS hexagonal nanosheet/graphene was fabricated by a facile one-pot microwave-thermal method. The samples possess excellent photocatalytic activity for degradation of organic pollutant under visible light. The high photocatalytic activity was attributed to the deposition of CuS hexagonal nanosheet onto graphene. CuS nanosheet serves as a transporter which efficiently inhibits the recombination of the photo-induced charge carriers in the nanocomposites. The developed method demonstrates a facile approach towards the synthesis of two-dimensional semiconductor-graphene nanocomposites with excellent photocatalytic performance under visible light.


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