PVP-assisted laser ablation growth of Ag nanocubes anchored on reduced graphene oxide (rGO) for efficient photocatalytic CO 2 reduction

Abstract(#br)Metallic nanoparticles loaded graphene nanocomposites have been widely studied for various scientific and technological applications. In this study, a facile method was reported to realize a straightforward growth of shape and size-controllable of metallic nanoparticles, and the subsequent hybridization with graphene in solution by strategically coupling wet-chemical route and laser ablation. By mixing graphene oxide (GO) with a tunable concentration level of polyvinylpyrrolidone (PVP) in aqueous solution, Ag nanocubes with a face-centered cubic crystal structure were generated by pulsed laser ablation and then mounted on GO nanosheets with the assistance of PVP. The preferential adsorption of PVP to Ag (100) crystal face led to the production of Ag nanocubes with exposed (100) facet. The result showed that the morphological yield of spherical particles decreased with the increase in PVP concentration. X-ray diffraction (XRD) and UV–visible spectroscopy analyses confirmed that GO was partially reduced. In the reduction of CO 2 gas, the photocatalytic conversion rate could achieve 133.1 μmol g −1 h −1 in 6 hrs for cubic Ag-loaded reduced GO composites

Spatial filtering effect of tip clearance using capacitance displacement sensor

Conference Name:2012 International Conference on Materials and Manufacturing Research, ICMMR 2012. Conference Address: Hong kong. Time:December 19, 2012 - December 20, 2012.According to structural characteristics and measurement needs of tip clearance of turbine engine and other rotating blade device, a leaves lattice model with vector characteristics is established. Based on measurement principle of the capacitive displacement sensor, the tip clearance measurement model is established. The spatial filtering effect and the impact of the tip clearance measurement results caused by blade thickness, sensing zone size, blade rotation speed and signal sampling rate is analyzed. The research results show that there is a minimum requirement about sensing zone size, blade rotation speed and signal sampling rate under the condition of certain blade thickness. The conclusion provides an important theoretical basis for the design of the tip clearance measurement system. ? (2013) Trans Tech Publications, Switzerland

Thermal-Assisted Laser Fabrication of Broadband Ultralow Reflectance Surface by Combining Marangoni Flow with In Situ Deposition

Functional surfaces with broadband ultralow optical reflectance have many potential applications in the fields of enhancing solar energy utilization, stray light shielding, infrared stealth, and so on. To fabricate broadband anti-reflection surfaces with low cost, high quality, and more controllability, a strategy of preparing multi-scale structures by thermal-assisted nanosecond laser was proposed. This strategy combines laser ablation with Marangoni flow of molten materials and in situ deposition of nanoparticles. The thermal-assisted strategy increases the depth to width ratio of the anti-reflection structures. The average reflectance of laser-textured TC4 (Ti-6Al-4V) surface is as low as 1.71% in the wavelength range of 200–2250 nm and 7.8% in the 2500–25,000 nm. The ultra-low reflectance surface has a significantly enhanced photothermal conversion performance. Meanwhile, the anti-reflection effect can be extended to the mid-infrared band, which has potential stealth application prospect. This synergetic manufacturing strategy has wide adaptability of materials, which provides new paths for the preparation of broadband ultralow reflectance surface. Moreover, this thermal-assisted laser fabrication strategy is prospective in the preparation of other functional micro-nano structures

Thermal-Assisted Laser Fabrication of Broadband Ultralow Reflectance Surface by Combining Marangoni Flow with In Situ Deposition

Functional surfaces with broadband ultralow optical reflectance have many potential applications in the fields of enhancing solar energy utilization, stray light shielding, infrared stealth, and so on. To fabricate broadband anti-reflection surfaces with low cost, high quality, and more controllability, a strategy of preparing multi-scale structures by thermal-assisted nanosecond laser was proposed. This strategy combines laser ablation with Marangoni flow of molten materials and in situ deposition of nanoparticles. The thermal-assisted strategy increases the depth to width ratio of the anti-reflection structures. The average reflectance of laser-textured TC4 (Ti-6Al-4V) surface is as low as 1.71% in the wavelength range of 200–2250 nm and 7.8% in the 2500–25,000 nm. The ultra-low reflectance surface has a significantly enhanced photothermal conversion performance. Meanwhile, the anti-reflection effect can be extended to the mid-infrared band, which has potential stealth application prospect. This synergetic manufacturing strategy has wide adaptability of materials, which provides new paths for the preparation of broadband ultralow reflectance surface. Moreover, this thermal-assisted laser fabrication strategy is prospective in the preparation of other functional micro-nano structures

The Effect of rGO-Doping on the Performance of SnO₂/rGO Flexible Humidity Sensor

The development of a flexible and high-performance humidity sensor is essential to expand its new applications, such as personal health monitoring and early diagnosis. In this work, SnO2/rGO nanocomposites were prepared by one-step hydrothermal method. The effect of rGO-doping on humidity sensing performance was investigated. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectroscopy were used to characterize the nanostructure, morphology and chemical composition of SnO2/rGO nanocomposites. The SnO2/rGO humidity sensitive film was prepared by electrospinning on a polyimide film modified with gold electrodes. The humidity test results show that different doping ratios of rGO have different effects on humidity sensing properties. Among them, the sensor with 2 wt% rGO-doping has a high sensitivity (37,491.2%) within the humidity range as well as the fast response time (80 s) and recover time (4 s). Furthermore, the sensor with 2 wt% rGO-doping remains good flexibility and stability in the case of bending (1000 times). The sensitivity of the 2 wt% rGO-doping sensor at the bending radius (8 mm and 4 mm) is 48,219% and 91,898%, respectively. More importantly, the sensor could reflect different breathing states clearly and track breathing intervals as short as 3 s. The SnO2/rGO flexible humidity sensor with accuracy, flexibility and instantaneity as well as the facile fabrication strategy is conceivable to be applied in the potential application for human health real-time monitoring

Electrophoretic Deposition of Graphene Oxide on Laser-Ablated Copper Mesh for Enhanced Oil/Water Separation

The fabrication of bionic surfaces resembling hydrophobic plants through micro manufacturing, which creates abundant multi-level micro/nanostructures and elemental variations, has been widely employed to change the surface wettability of metallic materials. Based on the mechanisms for selective permeation of various liquids, it could achieve the function of oil/water separation. Herein, a separation copper membrane fabricated with pulsed laser ablation and modified with graphene oxide (GO) deposition showed a synergetic effect on tunable surface wettability. Micro/nanostructures were generated on the copper substrate membrane through concentric circular scanning, which was followed by hole drilling. Afterwards, charged GO nanosheets were deposited via electrophoresis. The spacing of circular lines, the diameter of the holes and the abundant high-surface-energy hydrophilic oxygen contained in deposited GO amounts could be regulated in the laser processing and deposition, resulting in oleophobicity and hydrophilicity at the same time. The highest contact angle of oil in water of the prepared mesh could reach above 165° with a hole size of 200 µm and a circular line spacing of 100 µm after the laser processing. Water flux and oil-holding capacity, which represent the separation capability of the mesh, were also evaluated. The as-prepared separation mesh also showed great stability under harsh environments

General Strategy toward Laser Single-Step Generation of Multiscale Anti-Reflection Structures by Marangoni Effect

The anti-reflection of transparent material surfaces has attracted great attention due to its potential applications. In this paper, a single-step controllable method based on an infrared femtosecond laser is proposed for self-generation multiscale anti-reflection structures on glass. The multiscale composite structure with ridge structures and laser-induced nano-textures is generated by the Marangoni effect. By optimizing the laser parameters, multiscale structure with broadband anti-reflection enhancement is achieved. Meanwhile, the sample exhibits good anti-glare performance under strong light. The results show that the average reflectance of the laser-textured glass in the 300–800 nm band is reduced by 45.5% compared with the unprocessed glass. This work provides a simple and general strategy for fabricating anti-reflection structures and expands the potential applications of laser-textured glass in various optical components, display devices, and anti-glare glasses

Study of temperature decoupling fiber acceleration sensor based on the dual-FP structure

Conference Name:3rd International Conference on Engineering Design and Optimization, ICEDO 2012. Conference Address: Shaoxing, China. Time:May 25, 2012 - May 27, 2012.Zhejiang Provincial Natural Science Foundation of ChinaThere is seriously temperature coupling affection in the traditional fiber acceleration sensor, which affects the measurement accuracy. In order to improve anti-interference ability of the sensor, the structural characteristics of the dual-FP cavity is adapted to realize temperature decoupling. Based on the double-beam interference theory, the optimal film thickness requirements, and the output spectrum change of FP cavity caused by the vibration and temperature change is analyzed. Acceleration sensor with structure of the dual-FP cavity and three-bridge is designed. The sensor structure is analyzed by ANSYS software, such as the thickness of the bridges and the size of sensor, and cavity length change caused by equivalent force. Based on the analysis, it can be concluded that the corresponding bridge thickness is 100渭m and mass diameter is 0.5mm for the sensor with external diameter of 2 mm and inner diameter of 1.6mm. The resonant frequency of the system is 6.6kHz, and measuring range is 0 ~ 10g. 漏 (2012) Trans Tech Publications, Switzerland

Nanosecond laser ablation for enhanced adhesion of CuO nanowires on copper substrate and its application for oil-water separation

Applied Surface Science465995-100

Design of a POF receiver with integrated photodiode in 05m BCD process

Conference Name:2011 IEEE International Conference on Anti-Counterfeiting, Security and Identification, ASID 2011. Conference Address: Xiamen, China. Time:June 24, 2011 - June 26, 2011.IEEE Beijing Section; Xiamen UniversityDesign of a plastic optical fiber (POF) receiver with integrated photodiode in 0.5m BCD process is presented in the report. The receiver is intended to be used in the inbuilding network with POF, diameter 1mm wavelength 650nm. The receiver consists of an integrated PIN with 200m200m, a transimpedance amplifier (TIA) with an automatic gain control (AGC) loop and a post amplifier. The simulated 3dB frequency is shown up to 156.5MHz. 102.3 dB simulated transimpedance gain is achieved. ? 2011 IEEE