Lamellar nanoporous gold thin films with tunable porosity for ultrasensitive SERS detection in liquid and gas phase

Nanoscale ◽  
2020 ◽  
Vol 12 (23) ◽  
pp. 12602-12612 ◽  
Author(s):  
Adrien Chauvin ◽  
Marta Lafuente ◽  
Jean Yves Mevellec ◽  
Reyes Mallada ◽  
Bernard Humbert ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Phase ◽  
Chemical Etching ◽  
Lamellar Structure ◽  
Pure Copper ◽  
Nanoporous Gold ◽  
Pure Gold ◽  
Trace Level ◽  
Porous Gold ◽  
Sers Detection

Porous gold lamellar structure with high SERS performance is created by copper chemical etching of a pure gold and pure copper stacked layers. SERS response is recorded for trace level detection of probe molecule in liquid and gas phase.

scholarly journals Electrodeposition of Nanoporous Gold Thin Films

2020 ◽  
Author(s):  
Palak Sondhi ◽  
Keith J. Stine
Keyword(s):  
Thin Films ◽  
Drug Delivery ◽  
Electrical Conductivity ◽  
Heterogeneous Catalysis ◽  
High Surface ◽  
High Surface Area ◽  
Nanoporous Gold ◽  
Gold Films ◽  
Porous Gold ◽  
Self Assembling

Nanoporous gold (NPG) films have attracted increasing interest over the last ten years due to their unique properties of high surface area, high selectivity, and electrochemical activity along with enhanced electrical conductivity, and chemical stability. A variety of fabrication techniques to synthesize NPG thin films have been explored so far including dealloying, templating, sputtering, self-assembling, and electrodeposition. In this review, the progress in the synthetic techniques over the last ten years to prepare porous gold films has been discussed with emphasis given on the technique of electrodeposition. Such films have wide-ranging applications in the fields of drug delivery, energy storage, heterogeneous catalysis, and optical sensing.

scholarly journals Universal Fabrication of Highly Efficient Plasmonic Thin‐Films for Label‐Free SERS Detection

Small ◽  
2021 ◽  
pp. 2100755
Author(s):  
Sara Gullace ◽  
Verónica Montes‐García ◽  
Victor Martín ◽  
David Larios ◽  
Valentina Girelli Consolaro ◽  
...  
Keyword(s):  
Thin Films ◽  
Label Free ◽  
Highly Efficient ◽  
Sers Detection

NOHSO4/HF – A Novel Etching System for Crystalline Silicon

2007 ◽  
Vol 62 (11) ◽  
pp. 1411-1421 ◽  
Author(s):  
Sebastian Patzig ◽  
Gerhard Roewer ◽  
Edwin Kroke ◽  
Ingo över
Keyword(s):  
Gas Phase ◽  
Chemical Etching ◽  
Silicon Surface ◽  
Crystalline Silicon ◽  
Etching Solution ◽  
Wide Range ◽  
Ft Ir ◽  
Wet Chemical ◽  
Wet Chemical Etching ◽  
Etching System

Solutions consisting of HF - NOHSO4 - H2SO4 exhibit a strong reactivity towards crystalline silicon which is controlled by the concentrations of the reactive species HF and NO+. Selective isotropic and anisotropic wet chemical etching with these solutions allows to generate a wide range of silicon surface morphology patterns. Traces of Ag+ ions stimulate the reactivity and lead to the formation of planarized (polished) silicon surfaces. Analyses of the silicon surface, the etching solution and the gas phase were performed with scanning electron microscopy (SEM), DR/FT-IR (diffusive reflection Fourier transform infra-red), FT-IR, Raman and NMR spectroscopy, respectively. It was found that the resulting silicon surface is hydrogen-terminated. The gas phase contains predominantly SiF4, NO and N2O. Furthermore, NH4+ is produced in solution. The study has confirmed the crucial role of nitrosyl ions for isotropic wet chemical etching processes. The novel etching system is proposed as an effective new way for selective surface texturing of multi- and monocrystalline silicon. A high etching bath service lifetime, besides a low contamination of the etching solution with reaction products, provides ecological and economical advantages for the semiconductor and solar industry.

Photocatalytic degradation of 2-propanol over TiO2-based thin films in a simulated pilot microreactor

2021 ◽  
Vol 02 ◽  
Author(s):  
Corrado Garlisi ◽  
Ahmed Yusuf ◽  
Giovanni Palmisano
Keyword(s):  
Thin Films ◽  
Gas Phase ◽  
Continuous Flow ◽  
Molecular Diffusion ◽  
Batch Reactor ◽  
High Surface ◽  
Operating Conditions ◽  
Flow Mode ◽  
Doped Tio2 ◽  
Kinetics Of

Background: Microreactor devices have attracted increasing attention over the last years due to their high surface-to-volume ratio which ensures a high heat and mass transfer, short molecular diffusion distance and greater spatial illumination homogeneity compared to traditional reactors. Objective: The aim of this study was to model the kinetics of photodegradation of 2-propanol over TiO2-based thin films in a gas-phase batch-reactor and simulate their performance in a microreactor device. Methods: The reaction was carried out in a gas-phase batch-reactor assessing the reactivity of a single-layer nitrogen (N)-doped TiO2 and a bilayer consisting of N-doped TiO2 as a bottom layer and copper (Cu)-doped TiO2 as a top layer. The kinetics of the photocatalytic process was modelled by Langmuir–Hinshelwood (LH) model. The constants obtained from LH model were used to simulate the performance of the photocatalysts in a microreactor operating in a continuous flow mode and investigating the effect of the volumetric flow rate (Q), initial concentration of pollutant (Co), number of microchannels (n) and microchannel length (l) on the photodegradation of 2-propanol. Results: N-Cu-TiO2 exhibited a higher reactivity but a lower to adsorption ability towards the target pollutant compared to N-TiO2. To maximize and leverage the advantages of microreactor, optimal operating conditions for a continuous flow mode, at steady state, should be moderately low Q and Co, long l and moderate n that minimizes flow maldistribution in parallel. Conclusion: The findings in this work could serve as a basis to design and fabricate efficient microreactors for the removal of VOC in air purification applications.

Patterning of Bi-Sr-Ca-Cu-O thin films by wet chemical etching in EDTA

1992 ◽  
pp. 587-591
Author(s):  
F.J. Müller ◽  
J C Gallop ◽  
J.R. Laverty ◽  
M.A. Angadi ◽  
A.D. Caplin ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Etching ◽  
Wet Chemical ◽  
Wet Chemical Etching

scholarly journals PECVD of Hexamethyldisiloxane Coatings Using Extremely Asymmetric Capacitive RF Discharge

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2147
Author(s):  
Žiga Gosar ◽  
Janez Kovač ◽  
Denis Đonlagić ◽  
Simon Pevec ◽  
Gregor Primc ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Phase ◽  
Discharge Chamber ◽  
Depth Profiling ◽  
Dust Particles ◽  
Rf Discharge ◽  
Plasma Parameters ◽  
Entire Volume ◽  
Partial Pressures ◽  
Pressure Discharge

An extremely asymmetric low-pressure discharge was used to study the composition of thin films prepared by PECVD using HMDSO as a precursor. The metallic chamber was grounded, while the powered electrode was connected to an RF generator. The ratio between the surface area of the powered and grounded electrode was about 0.03. Plasma and thin films were characterised by optical spectroscopy and XPS depth profiling, respectively. Dense luminous plasma expanded about 1 cm from the powered electrode while a visually uniform diffusing plasma of low luminosity occupied the entire volume of the discharge chamber. Experiments were performed at HMDSO partial pressure of 10 Pa and various oxygen partial pressures. At low discharge power and small oxygen concentration, a rather uniform film was deposited at different treatment times up to a minute. In these conditions, the film composition depended on both parameters. At high powers and oxygen partial pressures, the films exhibited rather unusual behaviour since the depletion of carbon was observed at prolonged deposition times. The results were explained by spontaneous changing of plasma parameters, which was in turn explained by the formation of dust in the gas phase and corresponding interaction of plasma radicals with dust particles.

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