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Dual Functional S-Doped g-C3N4 Pinhole Porous Nanosheets for Selective Fluorescence Sensing of Ag+ and Visible-Light Photocatalysis of Dyes
摘要： This study explores the facile, template-free synthesis of S-doped g-C3N4 pinhole nanosheets (SCNPNS) with porous structure for fluorescence sensing of Ag+ ions and visible-light photocatalysis of dyes. As-synthesized SCNPNS samples were characterized by various analytical tools such as XRD, FT-IR, TEM, BET, XPS, and UV–vis spectroscopy. At optimal conditions, the detection linear range for Ag+ was found to be from 0 to 1000 nM, showing the limit of detection (LOD) of 57 nM. The SCNPNS exhibited highly sensitive and selective detection of Ag+ due to a significant fluorescence quenching via photo-induced electron transfer through Ag+–SCNPNS complex. Moreover, the SCNPNS exhibited 90% degradation for cationic methylene blue (MB) dye within 180 min under visible light. The enhanced photocatalytic activity of the SCNPNS was attributed to its negative zeta potential for electrostatic interaction with cationic dyes, and the pinhole porous structure can provide more active sites which can induce faster transport of the charge carrier over the surface. Our SCNPNS is proposed as an environmental safety tool due to several advantages, such as low cost, facile preparation, selective recognition of Ag+ ions, and efficient photocatalytic degradation of cationic dyes under visible light.
关键词： cationic dyes,pinhole porous nanosheet,photocatalytic degradation,visible light,Ag+ ions,S-doped g-C3N4,fluorescence sensing
更新于2025-09-19 17:15:36
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-doped yttrium orthophosphate nanoparticles tailored by co-precipitation route
摘要： Sm3+ doped yttrium orthophosphate nanoparticles with porous structure was synthesized via simple co-precipitation method. The structure, the morphology and the elemental composition of the tailored nanoparticles were investigated using transmission electron microscopy (TEM), powder X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDAX). Under the influence of trisodium citrate, Sm3+ doped YPO4 phosphor with porous structure could be synthesized. Under our reaction conditions, Sm3+ doped YPO4 nanophosphor crystallize in the hexagonal structure, as confirmed by the powder XRD patterns. The formation of porous structure turned out to be an essential step for the peculiar luminescent properties. The porosity undoubtedly enlarges the surface of the semiconductor/air interface, resulting in suppression of the non-radiative recombination channels. The tailored porous yttrium orthophosphate nanoparticles significantly displayed potentiality in the field of optical displays and also demonstrated the applicability in the biological field.
关键词： optical,non-radiative,biological field,porous,recombination channels,crystallize
更新于2025-09-19 17:15:36
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Flow Behaviors of Polymer Colloids and Curing Resins Affect Pore Diameters and Heights of Periodic Porous Polymer Films to Direct Their Surface and Optical Characteristics
摘要： Manipulation of both pore diameters and heights of two-dimensional periodic porous polymer films is important to extensively control their characteristics. However, except for using different sized colloid templates in replication methods, effective method that tunes these factors has rarely been reported. We find both parameters are controllable by adjusting the flow behaviors of polystyrene colloids and curing resin precursors while preparing phenolic resin and polydimethylsiloxane periodic porous films by embedding their precursors into colloidal crystal monolayers. We adjust the flow behaviors by either varying film preparation temperatures (≥ glass transition temperature of polystyrene) or using the precursors mixed with different amounts of a solvent that renders the colloids viscous. Consequently, the pore diameters and film heights change by 36–56% and 56–84%, respectively. Such modulation results in the change in height to dimeter ratios and the areal fractions of resins at air-film interfaces, thereby significantly changing the water contact angles on these surfaces and their photonic characteristics. This straightforward method does not require additional steps, differently sized colloids, or different amounts of precursors for these parameter controls.
关键词： polymer colloids,Periodic porous polymer films,flow behaviors,curing resins,simultaneous height and pore controls,replication method
更新于2025-09-19 17:15:36
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Ultrastable Luminescent Hybrid Bromide Perovskite@MOF Nanocomposites for the Degradation of Organic Pollutants in Water
摘要： Hybrid bromide perovskites (HBPs) have emerged as promising candidate in optoelectronic applications, although instability of the materials under working conditions has retarded the progress towards commercialization. As a rational approach to address this core issue, we herein report the synthesis of a series of ultrastable composite materials, wherein HBP nanocrystals (NCs) have been stabilised within a well-known chemically stable metal-organic framework (MOF) viz. zeolitic imidazolate framework (ZIF-8) via pore-encapsulated solvent directed (PSD) approach. The composites maintain their structural integrity as well as photoluminescence (PL) properties upon dipping into a wide range of polar solvents including water (even in boiling conditions), prolonged exposure to UV irradiation and elevated temperature for longer period of time. Further on the basis of high stability, HBP@MOF composites have been demonstrated as heterogeneous photocatalyst to degrade toxic organic pollutants directly in water.
关键词： photocatalysis,porous coordination polymer,stability of hybrid perovskite,Hybrid bromide perovskite,nanocomposites,luminescence properties
更新于2025-09-19 17:15:36
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Electrical Properties of Metal-Porous GaAs Structure at Water Adsorption
摘要： This paper reports the morphological, optical, luminescent and electrical properties of electrochemically made porous GaAs in order to evaluate their humidity sensing performance. The obtained porous GaAs exhibits non-homogenous surface morphology, which consists of pyramid-shaped crystallites and micropores. Photoluminescent and FTIR study shows that the surface of such material is covered by an oxide of As and Ga. The impedance spectroscopy was applied to analyze the influence of water vapor on electrical properties of metal-porous GaAs. It was shown that water adsorption results in the Nyquist plots shift to the region of higher frequencies. In humid atmosphere resistance Rv and characteristic time of charge accumulation s are decreased by 1.4 times and 5 times, respectively; resistance Rb and capacity Cb decreased by 1.4 times and 4.4 times, respectively. The response of the metal-porous GaAs structure to the adsorption of water is attributed to the decreasing of the bulk resistivity and potential barrier height. The formed oxide layer on the surface of porous GaAs plays a dual role—it increases the ability to adsorb water molecules and prevents the surface from receiving structural degradation.
关键词： SEM,DRIFT spectrum,impedance spectroscopy,Nyquist plot,Porous GaAs,humidity sensor
更新于2025-09-19 17:15:36
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[IEEE 2019 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Ottawa, ON, Canada (2019.7.8-2019.7.12)] 2019 International Conference on Numerical Simulation of Optoelectronic Devices (NUSOD) - Simulation of Lateral Near- and Far-Field Profiles of Gain-Guided High-Power Semiconductor Lasers
摘要： The conversion of electrical to mechanical power on a sub-centimeter scale is a key technology in many microsystems and energy harvesting devices. In this paper, we present a type of a capacitive energy conversion device that uses capillary pressure and electrowetting to reversibly convert electrical power to hydraulic power. These microhydraulic actuators use a high surface-to-volume ratio to deliver high power at a relatively low voltage with an energy conversion efficiency of over 65%. The capillary pressure generated grows linearly with shrinking capillary diameter, as does the frequency of actuation. We present the pressure, frequency, and power scaling properties of these actuators and demonstrate that power density scales up as the inverse capillary diameter squared, leading to high-efficiency actuators with a strength density exceeding biological muscle. Two potential applications for microhydraulics are also demonstrated: soft-microrobotics and energy harvesting.
关键词： electrowetting,Microhydraulics,porous materials,energy conversion,electrocapillary,microsystems,soft robotics,energy harvesting,microrobotics,actuator,microfluidics,PDMS
更新于2025-09-19 17:13:59
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Enhancement of photodetectors devices for silicon nanostructure from study effect of etching time by photoelectrochemical etching technique
摘要： Porous silicon (PS) prepared from n-type silicon via photoelectrochemical etching (PECE) technique. The morphology properties of PS specimens that formed with different etching time has been study utilize Scanning electron microscopy (SEM) and it show that the Layer of pore has sponge like stricture and the average pore diameter of PS layer rising with increase etching time. The X-ray diffraction (XRD) pattern indicated the nanocrystaline of the specimens, during these results; we showed improve behavior of PS photodetectors on a range of wavelengths.
关键词： Morphological properties,Porous silicon,Photodetectors,Photoelectrochemical etching
更新于2025-09-19 17:13:59
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Porous Si-SiO2 UV Microcavities to Modulate the Responsivity of a Broadband Photodetector
摘要： Porous Si-SiO2 UV microcavities are used to modulate a broad responsivity photodetector (GVGR-T10GD) with a detection range from 300 to 510 nm. The UV microcavity filters modified the responsivity at short wavelengths, while in the visible range the filters only attenuated the responsivity. All microcavities had a localized mode close to 360 nm in the UV-A range, and this meant that porous Si-SiO2 filters cut off the photodetection range of the photodetector from 300 to 350 nm, where microcavities showed low transmission. In the short-wavelength range, the photons were absorbed and did not contribute to the photocurrent. Therefore, the density of recombination centers was very high, and the photodetector sensitivity with a filter was lower than the photodetector without a filter. The maximum transmission measured at the localized mode (between 356 and 364 nm) was dominant in the UV-A range and enabled the flow of high energy photons. Moreover, the filters favored light transmission with a wavelength from 390 nm to 510 nm, where photons contributed to the photocurrent. Our filters made the photodetector more selective inside the specific UV range of wavelengths. This was a novel result to the best of our knowledge.
关键词： nanotechnology,photonic nanoscience,responsivity,porous Si-SiO2,UV filters
更新于2025-09-19 17:13:59
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AIP Conference Proceedings [AIP Publishing THE 7TH INTERNATIONAL CONFERENCE ON APPLIED SCIENCE AND TECHNOLOGY (ICAST 2019) - Karbala City, Iraq (27–28 March 2019)] THE 7TH INTERNATIONAL CONFERENCE ON APPLIED SCIENCE AND TECHNOLOGY (ICAST 2019) - Investigations of ZnO-NiO/PSi heterojunction for solar cell application
摘要： In this paper, ZnO-NiO nanocomposite has been successfully synthesized using chemical precipitation method .The structural properties were investigated using X-ray diffraction ( XRD) and field emission scanning electron microscope (FESEM) . XRD measurements confirms the formation of polycrystalline ZnO and NiO nanoparticles with a hexagonal and cubic structure respectively. The average grain size of ZnO-NiO nanocoposite estimated from FESEM was 60 nm . Heterojunction solar cell fabricated using ZnO-NiO nanocomposite on porous silicon by spray pyrolysis method shows open-circuit voltage (VOC) of 470 mV, short-circuit current density (ISC) of 39 mA/cm2, fill factor (FF) of 78.72% , and efficiency of 14.43%.
关键词： porous silicon,solar cell,chemical precipitation,ZnO-NiO nanocomposite,spray pyrolysis
更新于2025-09-19 17:13:59
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Glucose-derived porous carbon as a highly efficient and low-cost counter electrode for quantum dot-sensitized solar cells
摘要： Biomass-derived porous carbon is widely used in supercapacitors, carbon dioxide capture and lithium–sulfur batteries owing to its advantages such as wide sources, low cost and good stability. However, it is rarely used in quantum dot-sensitized solar cells (QDSCs). Here, glucose-derived porous carbon was obtained by hydrothermal carbonization followed with high-temperature KOH activation, and employed as an efficient counter electrode (CE) for QDSCs. The CV, EIS and Tafel-polarization analysis showed that porous carbon exhibits excellent catalytic activity for reduction of Sn2?. The CE based on porous carbon activated at 900 °C (C900) presents best performance with interface charge transfer resistance (Rct) of 2.4 Ω cm2 due to the synergy between high graphitization degree and large specific surface area. The power conversion efficiency (PCE) of the QDSCs assembled with a CdS/CdSe sensitized TiO2 photoanode and the C900 CE is up to 5.61% under one sun illumination. The excellent catalytic activity of C900 is attributed to its large specific surface area and porous structure and high degree graphitization. This suggests that glucose-derived porous carbon can become a potential low-cost and efficient CE material for QDSCs.
关键词： biomass-derived porous carbon,KOH activation,quantum dot-sensitized solar cells,hydrothermal carbonization,counter electrode,glucose
更新于2025-09-19 17:13:59