Carbon Dioxide Pressure and Catalyst Quantity Dependencies in Artificial Photosynthesis of Hydrocarbon Chains on Nanostructured Co/CoO Surfaces.

In this study, we investigated the influence of pressure and the quantity of Co/CoO catalyst on an artificial photosynthesis process that converts CO and HO into hydrocarbons (CH, where ≤ 18). The adsorption of CO and HO on Co/CoO surfaces proved to be pivotal in this photo-catalytic reaction. Photoexcited carbon dioxide and water molecules ((CO)* and (HO)*) generated by illuminating the catalyst surface led to the formation of alkene hydrocarbon molecules with carbon numbers following an approximate Poisson distribution.

Habitual feeding patterns impact polystyrene microplastic abundance and potential toxicity in edible benthic mollusks.

That increasing microplastics (MPs, <5 mm) eventually end up in the sediment which may become a growing menace to diverse benthic lives is worthy of attention. In this experiment, three edible mollusks including one deposit-feeding gastropod (Bullacta exarate) and two filter-feeding bivalves (Cyclina sinensis and Mactra veneriformis) were exposed to polystyrene microplastic (PS-MP) for 7 days and depurated for 3 days. PS-MP numbers in the digestive system and non-digestive system, digestive enzymes, oxidative stress indexes, and a neurotoxicity index of three mollusks were determined at day 0, 3, 7, 8 and 10.

Electroplating Cobalt Films on Silicon Nanostructures for Sensing Molecules.

In this study, we electroplated Co and Cu on nano-spiked silicon substrates that were treated with femtosecond laser irradiations. With energy-dispersive X-ray (EDX) analysis by a scanning electron microscope (SEM), it was found that both Co and Cu are primarily coated on the spike surfaces without changing the morphology of the nanospikes. We also found that nanoscale bridges were formed, connecting the Co-coated silicon spikes.

Study the plasmonic property of gold nanorods highly above damage threshold via single-pulse spectral hole-burning experiments.

Intense femtosecond laser irradiation reshapes gold nanorods, resulting in a persistent hole in the optical absorption spectrum of the nanorods at the wavelength of the laser. Single-pulse hole-burning experiments were performed in a mixture of nanorods with a broad absorption around 800 nm with a 35-fs laser with 800 nm wavelength and 6 mJ/pulse. A significant increase in hole burning width at an average fluence of 10 J/m has been found, suggesting a tripled damping coefficient of plasmon.

Highly In-Plane Anisotropic Two-Dimensional Ternary TaNiSe for Polarization-Sensitive Photodetectors.

Intriguing anisotropic electrical and optoelectrical properties in two-dimensional (2D) materials are currently gaining increasing interest both for fundamental research and emerging optoelectronic devices. Identifying promising new 2D materials with low-symmetry structures will be rewarding in the development of polarization-integrated nanodevices. In this work, the anisotropic electron transport and optoelectrical properties of multilayer 2D ternary TaNiSe were systematically researched.

Temperature Dependence of the Artificial Photosynthesis Reactions Catalyzed by Nanostructured Co/CoO.

Carbon dioxide (CO) and water (HO) have been converted into hydrocarbons at temperature ranging from 58 to 242 °C through an artificial photosynthesis reaction catalyzed by nanostructured Co/CoO. The experimental results show that chain hydrocarbons (alkane hydrocarbons) (C H, where 3 ≤ ≤ 16) mainly form at a temperature higher than about 60 °C, the production rate reaches a maximum at 130 °C, and abruptly decreases above 130 °C, and then gradually increases until 220 °C. While the temperature is higher than 220 °C, benzene (CH) and its derivatives such as toluene (CH), -xylene (CH), and CH form.

Femtosecond Laser-Induced Thermal Transport in Silicon with Liquid Cooling Bath.

Nanostructured regular patterns on silicon surface are made by using femtosecond laser irradiations. This is a novel method that can modify the surface morphology of any large material in an easy, fast, and low-cost way. We irradiate a solid surface with a 400-nm double frequency beam from an 800-nm femtosecond laser, while the solid surface is submerged in a liquid or exposed in air.

Detection of Liquid Penetration of a Micropillar Surface Using the Quartz Crystal Microbalance.

A quantitative characterization of the wetting states of droplets on hydrophobic textured surfaces requires direct measurement of the liquid penetration into surface cavities, which is challenging. Here, the use of quartz crystal microbalance (QCM) technology is reported for the characterization of the liquid penetration depth on a micropillar-patterned surface. The actual liquid-air interface of the droplet was established by freezing the droplet and characterizing it using a cryogenically focused ion beam/scanning electron microscope (cryo FIB-SEM) technique.

Surface-assisted laser desorption and ionization mass spectrometry using low-cost matrix-free substrates.

Surface-assisted laser desorption/ionization (SALDI) substrates have been fabricated using nanospiked polyurethane (PU) substrates that are replicated by a low-cost soft nanolithography method from silicon nanospike structures formed with femtosecond laser irradiations. The strongest mass spectrometry (MS) signal of Angiotensin II was obtained on 45-nm Au-coated nanospiked PU substrates. The effective ionization appears to be due to surface plasmon excitation.

The thresholds of surface nano-/micro-morphology modifications with femtosecond laser pulse irradiations.

We studied the pulse energy threshold of surface nano-/micro-morphology modifications by irradiating Si, GaAs, GaP, InP, Cu and Ti surfaces with 100 fs laser pulses at a wavelength of 800 nm in air and in water. We found that the laser pulse energy thresholds required for the permanent modification in water are up to 30% lower than those in air. Different non-equilibrium dynamics processes of the surface melting layer cause the different thresholds in water and in air.

Surface-enhanced Raman scattering sensor on an optical fiber probe fabricated with a femtosecond laser.

A novel fabrication method for surface-enhanced Raman scattering (SERS) sensors that used a fast femtosecond (fs) laser scanning process to etch uniform patterns and structures on the endface of a fused silica optical fiber, which is then coated with a thin layer of silver through thermal evaporation is presented. A high quality SERS signal was detected on the patterned surface using a Rhodamine 6G (Rh6G) solution. The uniform SERS sensor built on the tip of the optical fiber tip was small, light weight, and could be especially useful in remote sensing applications.

High-density regular arrays of nanometer-scale rods formed on silicon surfaces via femtosecond laser irradiation in water.

We report on the formation of high-density regular arrays of nanometer-scale rods using femtosecond laser irradiation of a silicon surface immersed in water. The resulting surface exhibits both micrometer-scale and nanometer-scale structures. The micrometer-scale structure consists of spikes of 5-10 mum width, which are entirely covered by nanometer-scale rods that are roughly 50 nm wide and normal to the surface of the micrometer-scale spikes.

Nanostructured magnetizable materials that switch cells between life and death.

Development of biochips containing living cells for biodetection, drug screening and tissue engineering applications is limited by a lack of reconfigurable material interfaces and actuators. Here we describe a new class of nanostructured magnetizable materials created with a femtosecond laser surface etching technique that function as multiplexed magnetic field gradient concentrators. When combined with magnetic microbeads coated with cell adhesion ligands, these materials form microarrays of 'virtual' adhesive islands that can support cell attachment, resist cell traction forces and maintain cell viability.

Visible and near-infrared responsivity of femtosecond-laser microstructured silicon photodiodes.

We investigated the current-voltage characteristics and responsivity of photodiodes fabricated with silicon that was microstructured by use of femtosecond-laser pulses in a sulfur-containing atmosphere. The photodiodes that we fabricated have a broad spectral response ranging from the visible to the near infrared (400-1600 nm). The responsivity depends on substrate doping, microstructuring fluence, and annealing temperature.

Subwavelength-diameter silica wires for low-loss optical wave guiding.

Silica waveguides with diameters larger than the wavelength of transmitted light are widely used in optical communications, sensors and other applications. Minimizing the width of the waveguides is desirable for photonic device applications, but the fabrication of low-loss optical waveguides with subwavelength diameters remains challenging because of strict requirements on surface roughness and diameter uniformity. Here we report the fabrication of subwavelength-diameter silica 'wires' for use as low-loss optical waveguides within the visible to near-infrared spectral range.