•Pomegranate structured C@pSi/rGO composite was prepared by high temperature pyrolysis and freeze drying technology.•Porous silicon is equivalent to pomegranate seeds providing sufficient ...capacity.•Coated carbon is equivalent to pulp which inhibits volume expansion and improve conductivity.•Graphene is equivalent to the fruit valves which accelerates ion transport and buffer volume change.•The cycling stability and rate capability of the material can be effectively improved.
A novel anode materials composed of pomegranate structured carbon @ porous silicon/reduced graphene oxide composite (C@pSi/rGO) was prepared by a facile high temperature pyrolysis and freeze drying technology. In this pomegranate-like composite, porous silicon is equivalent to pomegranate seeds providing sufficient specific capacity, the coated carbon layer is equivalent to pulp which can inhibit the volume expansion and improve electrical conductivity of silicon, and the outermost graphene is equivalent to the inner diaphragm and the outer fruit shell, which can accelerate the ion and electron transport and buffer the volume change of the inner silicon again, so that the cycling stability and rate performance of the material can be effectively improved. As a result, the initial discharge capacity of the C@pSi/rGO composite electrode is 825.7 mAh g−1, after 100 cycles, the reversible capacity of the C@pSi/rGO composite electrode can be maintained at 746 mAh g−1 at a current density of 0.4 A/g with a capacity retention up to 90.4%. However, for the pure porous silicon pSi electrode without carbon coating and graphene recombination, the initial discharge capacity is 769.4 mAh g−1 with almost 0% capacity retention after 30 cycles. Under the dual action of carbon coating and graphene composite, the performance of porous silicon electrode has been significantly improved, which will provide a new idea for the development of high performance silicon carbon anode materials.
A pomegranate structured of C@pSi/rGO composite composed of carbon coated porous Si and composite graphene was constructed, under the dual action of coated carbon and composite graphene, the conductivity of porous silicon electrode was significantly improved, and the volume expansion effect was effectively suppressed. As a result, the C@pSi/rGO electrode displays superior cycling stability and rate capability, which would provide a new idea for the development of high performance silicon carbon anode materials. Display omitted
Abstract Nanomaterials provide a unique platform for the development of theranostic systems that combine diagnostic imaging modalities with a therapeutic payload in a single probe. In this work, ...dual-labeled iRGD-modified multifunctional porous silicon nanoparticles (PSi NPs) were prepared from dibenzocyclooctyl (DBCO) modified PSi NPs by strain-promoted azide-alkyne cycloaddition (SPAAC) click chemistry. Hydrophobic antiangiogenic drug, sorafenib, was loaded into the modified PSi NPs to enhance the drug dissolution rate and improve cancer therapy. Radiolabeling of the developed system with111 In enabled the monitoring of the in vivo biodistribution of the nanocarrier by single photon emission computed tomography (SPECT) in an ectopic PC3-MM2 mouse xenograft model. Fluorescent labeling with Alexa Fluor 488 was used to determine the long-term biodistribution of the nanocarrier by immunofluorescence at the tissue level ex vivo . Modification of the PSi NPs with an iRGD peptide enhanced the tumor uptake of the NPs when administered intravenously. After intratumoral delivery the NPs were retained in the tumor, resulting in efficient tumor growth suppression with particle-loaded sorafenib compared to the free drug. The presented multifunctional PSi NPs highlight the utility of constructing a theranostic nanosystems for simultaneous investigations of the in vivo behavior of the nanocarriers and their drug delivery efficiency, facilitating the selection of the most promising materials for further NP development.
Significant progresses have been made to overcome the fundamental challenges in silicon (Si)-based lithium-ion batteries (LIBs). However, much less work have been reported on the design and failure ...analysis these batteries for practical applications. In this work, we analyzed various cell design parameters affecting the performance of pouch cells using micron-sized porous Si with nano-pore structure and coated by pitch-carbon (p-Si/C). The correlation among particle level, electrode level, and cell level properties, especially the effect of electrode density on the volumetric capacity density of Si anode and full batteries have been systematically investigated. It is found that the corrosion of p-Si/C particle surface is the main failure mechanisms on the eventual capacity loss, while Li plating on anode electrode surface is the main reason for the fast capacity loss in later stage of cycling. The volumetric capacity of Si anode highly depends on both electrode density and the Si content. Moreover, the prelithiation of Si anodes is found to increase energy density while decreasing cycle life of Si-based full cells. Finally, the pathways and strategies for adoption of micron-sized p-Si/C anodes in LIBs have been proposed for their practical applications.
Porous structured silicon has been regarded as a promising candidate to overcome pulverization of silicon-based anodes. However, poor mechanical strength of these porous particles has limited their ...volumetric energy density towards practical applications. Here we design and synthesize hierarchical carbon-nanotube@silicon@carbon microspheres with both high porosity and extraordinary mechanical strength (>200 MPa) and a low apparent particle expansion of ~40% upon full lithiation. The composite electrodes of carbon-nanotube@silicon@carbon-graphite with a practical loading (3 mAh cm
) deliver ~750 mAh g
specific capacity, <20% initial swelling at 100% state-of-charge, and ~92% capacity retention over 500 cycles. Calendered electrodes achieve ~980 mAh cm
volumetric capacity density and <50% end-of-life swell after 120 cycles. Full cells with LiNi
Mn
Co
O
cathodes demonstrate >92% capacity retention over 500 cycles. This work is a leap in silicon anode development and provides insights into the design of electrode materials for other batteries.
•The preparation was rapid and easy:•Synthesis of Tin Dioxide via Pulsed Laser Deposition.•Prepared porous silicon (PS) by photo-electrochemical etching method as substrate.•Various characterization ...techniques confirm the formation of S nO2 NPs/PS.•Good Photo-detection Performance was shown by the material.
In this study, we have covered a porous silicon (PS) layer with tin dioxide (SnO2) nanostructured via a pulsed laser deposition process to produce a broadband photoresponse device. The impact of laser fluence on the optical, electrical, and structural characteristics of the fabricated photodetector was identified. The optical features analysis indicated that the SnO2 films covered on porous silicon have a direct energy gap varying from 3.62 to 3.67 eV as a function of laser fluence. The X-ray diffraction investigation proved that the SnO2 nanostructure has a tetragonal rutile nature. The Field-emission scanning electron microscopy emphasised that produced SnO2 nanostructures have a mean size of 81.76–98.68 nm, and nanoparticle agglomeration was remarked. The photoluminescence emissions of SnO2 nanostructure placed on porous silicon displayed a variety of overlapping intensities in the near-ultraviolet/visible spectrum between 369 and 506 nm, while the intense red band decreased in intensity and shifted towards longer wavelengths. Fourier-transformed infrared spectroscopy investigation indicates the existence of the Sn-O-Si bond in the formed structure.
The dependence of the optoelectronic characteristics of PS/n-Si and SnO2/PS/n-Si photodetector on laser fluence has been performed. Produced heterojunctions have remarkable rectification properties with ideality factors ranging from 2.27 to 2.91, relying on the laser fluence. The spectral responsivity analysis showed that SnO2/PS/n-Si photodetectors exhibit three response bands at ∼366 nm, ∼621 nm, and ∼806 nm, regarding the highest responsivity of 0.21 A/W, 0.33 A/W, and 0.43 A/W, respectively. The findings suggest that SnO2/PS/n-Si heterojunction photodetectors are suitable for developed ultraviolet–visible light detection enhanced photodiodes that are cost-effective and convenient for use in wearable and portable devices without expensive extra gadgets.
•A new real-time monitoring method for alcohol content in spirit samples based on stable TiO2-coated porous silicon interferometer has been established.•The alcohol content of spirit sample can be ...measured by the efficient optical thickness or the reflection peak of sensing film and the detection principles have been discussed.•The new established detection method for alcohol content has been compared with alcoholmeter and rugate TiO2-porous silicon sensing substrate.•The new developed method displays a sensitivity of 2.911 nm/alcohol content unit and linear detection range in 10%–70%(v/v) in spirit samples.•The developed method is a rapid, sensitive, on-line, and cost-efficient detection technique without sample pretreatment for alcohol content.
A new real-time monitoring method for alcohol content in spirit samples has been established on base of stable TiO2-coated porous silicon (PSi) interferometer. There is a linear relationship between the different alcohol contents in range of 10%–70% (v/v) and efficient optical thickness (EOT) or the reflection peak positions of the sensing film. The alcohol content of sample can be measured by the EOT or the reflection peak positions with the TiO2 coated PSi interferometer. Both the straight TiO2-PSi and rugate TiO2-PSi can detect the alcohol contents, but the former displays a sensitivity of 2.911 nm ± 0.145/alcohol content unit (ACU) which is fifty times more sensitive than that of the latter. The developed method is a rapid, sensitive, on-line, and cost-efficient detection technique without sample pretreatment for alcohol content in spirit samples. The results detected by the developed method for alcohol content in nine spirit samples are agreement with that of traditional alcoholmeter method. The novel established method has a great potential in food industry, environment and health fields for monitoring alcohol content.
In this work an optical calcium sensor is fabricated using calmodulin surface functionalized macro-porous silicon. Porous silicon is prepared by electro-chemical etching process on silicon wafers, ...which were further calmodulin surface functionalized for effective calcium binding. Porous silicon provides many fold increase in surface area to volume ratio for absorption, and calmodulin provides effective calcium binding sites. Investigating with different bi-valent and mono-valent cations, the fabricated structure shows effective selectivity and multi-parametric optical response for calcium ions. Several Optical parameters such as reflectance, scattering loss and absorption loss were measured for calcium and other bi-valent and mono-valent cations at physiologically relevant concentrations, the sensor showed great discrimination towards calcium ion. Calcium being the most abundant cation present in the human body plays a significant role in cellular signalling pathways. Moreover Calcium is abundant in drinking water and is important for ecosystem maintenance. The sensor fabricated in this work finds application in calcium sensing in drinking water samples as well as in serum. Thus the sensor provides a highly sensitive, easy to use and cost-effective alternative for calcium detection and sensing.
A sensitive, rapid and direct electrochemistry sensor for bisphenol propane (BPA) has been developed by a stable three-dimensional porous silicon-carbon-gold (3D PS-C-Au) electrode. The 3D PS-C-Au ...electrode shows a good stability in the different pH solution for 5 h and good electroactivity for BPA, which has a great potential application in food and environmental safety fields.
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•A new direct electrochemistry sensor for bisphenol A (BPA) has been developed.•The cyclic voltammetry for BPA is performed by a stable three-dimensional porous silicon-carbon-gold (3D PS-C-Au) electrode.•The 3D PS-C-Au electrode has been prepared by carbonizing and nano-Au layers on porous silicon.•The 3D PS-C-Au electrode shows a good stability and good electroactivity for BPA.•The sensor exhibited a rapid response, a wider linear detection range, low detection limit and high recovery ratios for BPA.
A sensitive, rapid and directly electrochemical sensor for bisphenol A (BPA) has been developed based on a stable three-dimensional porous silicon-carbon-gold (3D PS-C-Au) electrode. The 3D PS-C-Au film was prepared by electrochemical etching of single-crystal Si wafers, carbonizing layer of poly (fururyl) alcohol (PFA) and sputter of nano-Au layer. The 3D PS-C-Au electrode displayed good stability in different pH solution for 5 h and good electroactivity for BPA. The cyclic voltammetry results showed that the sensor exhibited a rapid response, a wider linear detection range from 5.0 × 10−8 to1.0 × 10−5 mol/L BPA with a detection limit of 3.5 × 10−9 mol/L(3S/N). The developed method has been applied in real samples with good recovery rates ranging from 82.30% to 104.10%. The enhanced performance for direct BPA detection can be ascribed to the large internal surface area and the electrostatic adsorption properties to BPA. The 3D PS-C-Au film shows good optical and electrical characteristics, giving a great potential application of the sensor in food and environmental safety fields.
FESEM surface morphology and the schematic illustration of porous silicon filled Pd decorate SiC nanocauliflowers thin film sensor with Ag paste contacts.
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•Pd decorated SiC ...nanocauliflowers (NCs) thin film have been directly fabricated on porous silicon substrates using reactive DC co-sputtering technique.•Hydrogen sensing properties Pd/SiC nanocauliflowers sensor have been investigated.•Pd/SiC NCs sensor exhibits the high response with fast response/recovery towards (5–500) ppm H2 gas at relatively high temperature regime (40–500 °C).
In this work, we have fabricated the Pd decorated silicon carbide (SiC) nanocauliflowers (NCs) thin films on electrochemically etched porous silicon (PS) substrate by DC magnetron co-sputtering technique. The gas sensing performance of Pd/SiC NCs to hydrogen gas under low (5–500 ppm) detection limit at high operating temperature regime (40–500 °C) were studied in detail without additional processing. The nanocauliflowers sensor demonstrates the high sensing response (Ra/Rg ̴ 14.48), fast response/recovery time (10s/18s) with excellent stability (24 cycles) towards 100 ppm H2 at high temperature of 380 °C. The underlying sensing mechanism behind the notable performance of the proposed sensing action towards H2 was also discussed in detail. Therefore, the investigated Pd/SiC NCs can be used as highly sensitive and selective hydrogen gas sensor at high working temperatures in harsh environment.
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