Noble metal nanoparticle-decorated TiO2 nanobelts for enhanced photocatalysis

2014 ◽  
Vol 07 (05) ◽  
pp. 1450064 ◽  
Author(s):  
Haiyan He ◽  
Ping Yang ◽  
Changchao Jia ◽  
Yanping Miao ◽  
Jie Zhao ◽  
...  

TiO 2 nanobelts have been fabricated through a hydrothermal method and subsequently sulfuric-acid-corrosion-treated for a rough surface. Noble metal nanoparticles such as Ag and Au were deposited on the coarse surface of TiO 2 nanobelts via a coprecipitation procedure. Ag – TiO 2 nanobelts were prepared in ethanolic solution contained silver nitrate ( AgNO 3) and sodium hydroxide ( NaOH ). Au – TiO 2 nanobelts were obtained in chloroauric acid ( HAuCl 4) using sodium borohydride ( NaBH 4) as the reductant. It is confirmed by the results of XRD patterns together with the SEM images that the composite of noble metal and TiO 2 nanobelts were obtained successfully and the Ag or Au nanoparticles were well-dispersed on the TiO 2 nanobelts. Moreover, the as-prepared Ag and Au nanoparticle-decorated TiO 2 nanobelts represent an enhanced photocatalytic activity compared with pure TiO 2 nanobelts, which is due to the fact that the Ag and Au nanoparticles on the surface of TiO 2 nanobelts act as sinks for the photogenerated electrons and promote the separation of the electrons and holes.

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).


2021 ◽  
Vol 21 (5) ◽  
pp. 3107-3114
Author(s):  
Zhuo-Rui Li ◽  
Geng Zhu ◽  
Guo-Zhi Han

We firstly discover the enhanced catalytic activity of magnetic noble metal nanoparticles mediated by surface plasmon resonance. Under light irradiation with certain wavelength, the catalytic performance of magnetic noble metal nanoparticles shows changes with different degrees and directions that are associated with the surface plasmon resonance (SPR) of the noble metal. Moreover, the coupling of silver and gold allows the catalytic performance of magnetic bimetallic Ag–Au nanoparticles to show more positive response to surface plasmon resonance. The magnetic bimetallic Ag–Au nanoparticles show excellent catalytic performance toward the reduction reaction of aromatic nitro group, and corresponding rate constant of the catalytic reduction reaction increases about three times with light irradiation.


2016 ◽  
Vol 40 (1) ◽  
pp. 724-731 ◽  
Author(s):  
Jayeeta Bhaumik ◽  
Gitanjali Gogia ◽  
Seema Kirar ◽  
Lekshmi Vijay ◽  
Neeraj S. Thakur ◽  
...  

Conjugatable and compact porphyrinic photosensitizer nanoparticle conjugates were developed through rational synthesis followed by conjugation with noble metal nanoparticles.


2009 ◽  
Vol 620-622 ◽  
pp. 185-188 ◽  
Author(s):  
Yamato Hayashi ◽  
Masahiro Inoue ◽  
Ichitito Narita ◽  
Katsuaki Suganuma ◽  
Hirotsugu Takizawa

Applications of various noble metal nanoparticles were investigated for newly, ecology and economy home electric appliances (microwave, ultrasonic) used system. Noble metal oxides have merit in metal particles fabrication, as one of these example example, there are decomposed by only heating in air. That is, noble metal oxide don't use strong reduction atmosphere. This reduction is ecologically clean, because many noble metal oxides are not toxic and during decomposition O2 is evolved. We have reduced noble metal oxides by microwave and ultrasound, and tried to fabricate noble metal nanoparticles, and investigated various processing. These energy are widely used by home electric appliances. By choosing suitable process and conditions, it is reasonable to expect that home electric appliances ecology and economy fabrications can be extended to obtain simply various noble metal nanoparticles related materials.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Pingfeng Fu ◽  
Pengyi Zhang ◽  
Jia Li

Simultaneous removal of low concentration formaldehyde (HCHO) and ozone byproduct was investigated in the gaseous VUV (vacuum ultraviolet) photocatalysis by using noble metal modified TiO2films. Noble metal (Pt, Au, or Pd) nanoparticles were deposited on TiO2films with ultrafine particle size and uniform distribution. Under 35 h VUV irradiation, the HCHO gas (ca. 420 ppbv) was dynamically degraded to a level of 10~45 ppbv without catalyst deactivation, and over 50% O3byproduct wasin situdecomposed in the reactor. However, under the same conditions, the outlet HCHO concentration remained at 125~178 ppbv in the O3+ UV254 nmphotocatalysis process and 190~260 ppbv in the UV254 nmphotocatalysis process. And the catalyst deactivation also appeared under UV254 nmirradiation. Metallic Pt or Au could simultaneously increase the elimination of HCHO and ozone, but the PdO oxide seemed to inhibit the HCHO oxidation in the UV254 nmphotocatalysis. Deposition of metallic Pt or Au reduces the recombination of h+/e−pairs and thus increases the HCHO oxidation and O3reduction reactions. In addition, adsorbed O3may be partly decomposed by photogenerated electrons trapped on metallic Pt or Au nanoparticles under UV irradiation.


COSMOS ◽  
2007 ◽  
Vol 03 (01) ◽  
pp. 103-124 ◽  
Author(s):  
A. SREEKUMARAN NAIR ◽  
RENJIS T. TOM ◽  
V. R. RAJEEV KUMAR ◽  
C. SUBRAMANIAM ◽  
T. PRADEEP

In this paper, a summary of some of the recent research efforts in our laboratory on chemical interactions at noble metal nanoparticle surfaces is presented. The article is divided into five sections, detailing with (i) interactions of simple halocarbons with gold and silver nanoparticle surfaces at room temperature by a new chemistry and the exploitation of this chemistry in the extraction of pesticides from drinking water, (ii) interaction of biologically important proteins such as Cyt c, hemoglobin and myoglobin as well as a model system, hemin with gold and silver nanoparticles and nanorods forming nano–bio conjugates and their surface binding chemistry, (iii) formation of polymer–nano composites with tunable optical properties and temperature sensing characteristics by single and multi-step methodologies, (iv) nanomaterials-based flow sensors and (v) composites of noble metal nanoparticles and metallic carbon nanotubes showing visible fluorescence induced by metal–semiconductor transition.


RSC Advances ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 6329-6335 ◽  
Author(s):  
Wenjiang Li ◽  
Yanhua Wang ◽  
Min Zeng ◽  
Jingyang Jiang ◽  
Zilin Jin

We mainly expanded an easy, highly efficient, and continuously reversible hydrogen-bond-selective phase transfer directed towards noble metal (Pt, Ru, Ir, Pd, and Au) nanoparticles.


2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Shailee Shroff ◽  
Chad Curtis

metal nanoparticles have been used to address these diseases in the brain, however very few of these formulations have made it through clinical trials. This review will be discussing the role of noble metal nanoparticles as drug delivery systems specifically to the brain. A common problem many researchers and clinical physicians are facing problems because they are unable to access the brain without highly invasive surgery. Nanoparticles allow access to the brain without invasive surgery. Noble metal nanoparticles (NMNPs) are of particular interest because of their inherent characteristics which are amplified or reduced by ligands. The various ligands available change the method of transportation for a NMNPs traveling through the blood barrier. We will examine various ligands and their benefits and potential drawbacks. Furthermore, the optimal usage for each ligand and associated nanoparticle will also be examined. This review will go into detail about pure noble metal nanoparticle, glucose, PEG, CTAB, Transferrin, Anti-Microbial Peptide, and Chitosan as coatings. All of these are commonly used among researchers. The absorptivity into various cell types in the brain along with future implications will be examined.


2020 ◽  
Vol 11 ◽  
pp. 1439-1449
Author(s):  
Mathias Franz ◽  
Romy Junghans ◽  
Paul Schmitt ◽  
Adriana Szeghalmi ◽  
Stefan E Schulz

The wafer-level integration of high aspect ratio silicon nanostructures is an essential part of the fabrication of nanodevices. Metal-assisted chemical etching (MACE) is a promising low-cost and high-volume technique for the generation of vertically aligned silicon nanowires. Noble metal nanoparticles were used to locally etch the silicon substrate. This work demonstrates a bottom-up self-assembly approach for noble metal nanoparticle formation and the subsequent silicon wet etching. The macroscopic wafer patterning has been done by using a poly(methyl methacrylate) masking layer. Different metals (Au, Pt, Pd, Cu, and Ir) were investigated to derive a set of technologies as platform for specific applications. Especially, the shape of the 3D structures and the resulting reflectance have been investigated. The Si nanostructures fabricated using Au nanoparticles show a perfect light absorption with a reflectance below 0.3%. The demonstrated technology can be integrated into common fabrication processes for microelectromechanical systems.


2017 ◽  
Vol 6 (3) ◽  
pp. 301-329 ◽  
Author(s):  
Hedieh Malekzad ◽  
Parham Sahandi Zangabad ◽  
Hamed Mirshekari ◽  
Mahdi Karimi ◽  
Michael R. Hamblin

AbstractThe aim of this review is to cover advances in noble metal nanoparticle (MNP)-based biosensors and to outline the principles and main functions of MNPs in different classes of biosensors according to the transduction methods employed. The important biorecognition elements are enzymes, antibodies, aptamers, DNA sequences, and whole cells. The main readouts are electrochemical (amperometric and voltametric), optical (surface plasmon resonance, colorimetric, chemiluminescence, photoelectrochemical, etc.) and piezoelectric. MNPs have received attention for applications in biosensing due to their fascinating properties. These properties include a large surface area that enhances biorecognizers and receptor immobilization, good ability for reaction catalysis and electron transfer, and good biocompatibility. MNPs can be used alone and in combination with other classes of nanostructures. MNP-based sensors can lead to significant signal amplification, higher sensitivity, and great improvements in the detection and quantification of biomolecules and different ions. Some recent examples of biomolecular sensors using MNPs are given, and the effects of structure, shape, and other physical properties of noble MNPs and nanohybrids in biosensor performance are discussed.


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