This article presented a facile fabrication process for polydimethylsiloxane(PDMS)composite gold nanotris⁃octahedra(Au NTOH)for a flexible SERS sensor with high sensitivity.Specifically,Au NTOH with excellent SERS beh...This article presented a facile fabrication process for polydimethylsiloxane(PDMS)composite gold nanotris⁃octahedra(Au NTOH)for a flexible SERS sensor with high sensitivity.Specifically,Au NTOH with excellent SERS behaviors was synthesized using a seed-mediated growth method and the dimensions of the Au NTOH was easily tuned.In addition,the influence of size on the SERS performance of their monolayers was systematically investigated,and the Au NTOH with the size of 61 nm possessed the best SERS performance.Importantly,a hydrophilic-substrateassisted interfacial self-assembled monolayer transfer technique was proposed to transfer Au NTOH onto PDMS films,resulting in forming flexible and transparent Au NTOH@PDMS substrates.Furthermore,the excellent signal homoge⁃neity of this substrate was demonstrated and the sensitivity was verified by a measurement of crystal violet(CV)as low as 1×10^(-8) mol/L.As a result,this SERS sensor is progressing for applying in the identification of trace contaminants in broad fields.展开更多
In the current study novel magnetic BiOBr-Gd^(3+)doped CoFe_(2)O_(4)heterojunction nanocomposites fabricated by chemical precipitation method for Acid Violet 7(AV 7)and Reactive Red 120(RR 120)dye degradation under su...In the current study novel magnetic BiOBr-Gd^(3+)doped CoFe_(2)O_(4)heterojunction nanocomposites fabricated by chemical precipitation method for Acid Violet 7(AV 7)and Reactive Red 120(RR 120)dye degradation under sunlight are presented.The samples were well characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM),scanning electron microscopy(SEM),energy dispersive X-ray analysis(EDAX),UV-visible near infrared(NIR),photoluminescence(PL),TRF,EIS,Mott-Schottky,and BET analysis.X-ray diffractograms of BiOBr-Gd^(3+)doped CoFe_(2)O_(4)nanocomposites authenticate the formation of the composite composed of diffraction peaks of both BiOBr and Gd^(3+)doped CoFe_(2)O_(4)samples.Photoluminescence(PL),Time Resolved Fluorescence Spectrocopy(TRF)and Electrochemical Impedance Spectroscopy(EIS)investigations were explored to examine the transfer efficiency of photoinduced charge carriers.Among the synthesized materials,the BiOBr-Gd^(3+)doped CoFe_(2)O_(4)-2 nanocomposite presents superior degradation capability for RR 120 of 87.34%and AV 7 dyes of 98.41%.The apparent rate constant(k)value of 0.1317 min^(-1)for AV 7 is sixteen times higher and RR 120(0.0135 min^(-1))is 2 times higher than pristine BiOBr.The radical trapping experiments also proved the role of photogenerated h^(+),O_(2)·^(-),and·OH radicals in the degradation mechanism.The superior performance of BiOBr-Gd^(3+)doped CoFe_(2)O_(4)-2 is ascribed to the formation of the heterostructure,the in-built electric field,and energy-band alignment,which thermodynamically and kinetically favors the photoactivity and stability of the heterojunction.展开更多
The crossmodal interaction of different senses,which is an important basis for learning and memory in the human brain,is highly desired to be mimicked at the device level for developing neuromorphic crossmodal percept...The crossmodal interaction of different senses,which is an important basis for learning and memory in the human brain,is highly desired to be mimicked at the device level for developing neuromorphic crossmodal perception,but related researches are scarce.Here,we demonstrate an optoelectronic synapse for vision-olfactory crossmodal perception based on MXene/violet phosphorus(VP)van der Waals heterojunctions.Benefiting from the efficient separation and transport of photogenerated carriers facilitated by conductive MXene,the photoelectric responsivity of VP is dramatically enhanced by 7 orders of magnitude,reaching up to 7.7 A W^(−1).Excited by ultraviolet light,multiple synaptic functions,including excitatory postsynaptic currents,pairedpulse facilitation,short/long-term plasticity and“learning-experience”behavior,were demonstrated with a low power consumption.Furthermore,the proposed optoelectronic synapse exhibits distinct synaptic behaviors in different gas environments,enabling it to simulate the interaction of visual and olfactory information for crossmodal perception.This work demonstrates the great potential of VP in optoelectronics and provides a promising platform for applications such as virtual reality and neurorobotics.展开更多
A biosorbent prepared from powdered mycelial biomass of Ceriporia lacerata （CLB）, a basidiomycetous fungus, was applied for the uptake of Crystal Violet from aqueous solution. A batch adsorption experiment was used ...A biosorbent prepared from powdered mycelial biomass of Ceriporia lacerata （CLB）, a basidiomycetous fungus, was applied for the uptake of Crystal Violet from aqueous solution. A batch adsorption experiment was used for the biosorption process, involving effect of experimental factors and biosorption kinetics and equilibrium. Biosorption process showed that the removal of Crystal Violet by CLB was effective over wide pH range, and meanwhile was independent on ionic strength. Biosorption capacities of CLB increased with the initial dye concentration increasing, due to an increase in the driving force of the concentration gradient. The adsorbed Crystal Violet amount per unit biomass weight decreased with increasing biosorbent dosage, due to the splitting effect of flux （concentration gradient） between sorbate and biosorbent. A maximum sorption capacity of 239.25 mg/g was observed. Biosorption kinetics was found to be best represented by the pseudo second-order kinetic model. The equilibrium adsorption data was well described by the Koble-Corrigan model. FT-IR （Fourier Transform Infrared Spetroscopy） spectrum showed the presence of O–H, COOH, C=O, C–N, C–H, –NH2 and P–OH in the surface of CLB as functional groups. This study showed CLB can effectively remove CV from dye wastewater.展开更多
The adsorption of Methyl Violet （MV） cationic dye from aqueous solution was carried out by using crosslinked poly （acrylic acid-coacrylamide）/attapulgite （Poly（AA-co-AM）/ATP） composite as adsorbent. The factor...The adsorption of Methyl Violet （MV） cationic dye from aqueous solution was carried out by using crosslinked poly （acrylic acid-coacrylamide）/attapulgite （Poly（AA-co-AM）/ATP） composite as adsorbent. The factors influencing adsorption capacity of the composite such as pH, concentration of the dye, temperature, contact time, adsorbent dosage, ionic strength and surfactant were systematically investigated. The equilibrium data fitted very well to the Langmuir isotherm and the maximum adsorption capacity reached 1194 mg/g at 30℃. The thermodynamic parameters including △G0, △H0 and △S0 for the adsorption processes of MV on the composite were also calculated, and the negative △H0 and △G0 confirmed that the adsorption process was exothermicand spontaneous. The kinetic studies showed that the adsorption process was consistent with the pseudo second-order kinetic model and the desorption studies revealed that the regeneration of the composite adsorbent can be easily achieved.展开更多
Highly active, stable and affordable surface enhanced Raman scattering （SERS） substrates were obtained by electrolyzing a mixture of AgNO3 （4 × 10^-4 mol/L） and Na3C6H5OTH2O （6 × 10^-5 mol/L） for 1, 2,...Highly active, stable and affordable surface enhanced Raman scattering （SERS） substrates were obtained by electrolyzing a mixture of AgNO3 （4 × 10^-4 mol/L） and Na3C6H5OTH2O （6 × 10^-5 mol/L） for 1, 2, 3 and 4 h at 7 V. With crystal violet （CV） as a test molecule, a portable Raman spectrometer with 785 nm laser excitation was employed to carry out the SERS detection. Colloidal Ag nanoparticles prepared by electrolyzing for 3 h with the particle size of （65 ±17） nm is a perfect SERS substrate for the ultratrace detection of CV, which displayed an enhancement factor of ca. 1.3 × 10^8 and the detection limit of CV is down to ca. 10-15 mol/L （ca. 10^-4 ppb） with 10^-1 mol/L KBr as aggregating agent. Thus, this SERS substrate will provide a hopeful foreground in ultratrace detection. Meanwhile, it will provide a possibility to bring Raman analysis out of the laboratory to process in situ, real-time detection and identification.展开更多
Agrobacterium radiobacter MTCC 8161 completely decolorized the Crystal Violet with 8 hr （10 mg/L） at static anoxic conditions. The decreased decolorization capability by A. radiobacter was observed, when the Crystal...Agrobacterium radiobacter MTCC 8161 completely decolorized the Crystal Violet with 8 hr （10 mg/L） at static anoxic conditions. The decreased decolorization capability by A. radiobacter was observed, when the Crystal Violet concentration was increased from 10 to 100 mg/L. Semi-synthetic medium containing 1% yeast extract and 0.1% NH4C1 has shown 100% decolorization of Crystal Violet within 5 hr. A complete degradation of Crystal Violet by A. radiobacter was observed up to 7 cycles of repeated addition （10 rag/L）. When the effect of increasing inoculum concentration on decolorization of Crystal Violet （100 mg/L） was studied, maximum decolorization was observed with 15% inoculum concentration. A significant increase in the activities of laccase （184%） and aminopyrine N-demethylase （300%） in cells obtained after decolorization indicated the involvement of these enzymes in decolorization process. The intermediates formed during the degradation of Crystal Violet were analyzed by gas chromatography and mass spectroscopy （GC/MS）. It was detected the presence of N,N,N＇,N＂-tetramethylpararosarfiline, IN, N-dimethylaminophenyl] [N-methylaminophenyl] benzophenone, N, N-dimethylaminobenzaldehyde, 4-methyl amino phenol and phenol. We proposed the hypothetical metabolic pathway of Crystal Violet biodegradation by A. radiobacter. Phytotoxicity and microbial toxicity study showed that Crystal Violet biodegradation metabolites were less toxic to bacteria （A. radiobacter, P. aurugenosa and A. vinelandii） contributing to soil fertility and for four kinds of plants （Sorghum bicolor, Vigna radiata, Lens culinaris and Triticum aestivum） which are most sensitive, fast growing and commonly used in Indian agriculture.展开更多
Fe（III） immobilized fire clay （Fe-FC） was prepared using ferric nitrate by solid state dispersion method and this hetero-Fenton catalyst was applied for the degradation of Acid Violet 7 （AV 7） under natural sunl...Fe（III） immobilized fire clay （Fe-FC） was prepared using ferric nitrate by solid state dispersion method and this hetero-Fenton catalyst was applied for the degradation of Acid Violet 7 （AV 7） under natural sunlight. The 26% ferric nitrate loaded fire clay was found to be most efficient. The experimental conditions such as solution pH, H2O2 concentration for efficient degradation of AV 7 have been determined. Unlike Fenton catalyst, Fe-FC is photoactive over a wide pH range of 3-7. This catalyst was found to be stable and reusable. The GC-MS analysis of experimental solutions during irradiation revealed the formation of 2,8-diaminonaphthalene-1,3,6- triol, 8-aminonaphthalene-1,2,3,6-tetrol, 2-aminonaphthalene-1,3,6,8-tetrol and 2-aminobenzene-1,3-diol/5-aminonbenzene-1,3-diol/ 2-aminobenzene-1,4-diol as intermediates. The 26% ferric nitrate loaded fire clay was characterized by XRD, ICP-AES, BET surface area, FT-IR, SEM-EDS and UV-DRS studies.展开更多
TiO_2 nanoparticles with different phases are prepared by hydrolysis oftitanium tetrabutoxide in the presence of HC1. The composition and microstructure of the resultingsamples are studied by XRD and TEM. These result...TiO_2 nanoparticles with different phases are prepared by hydrolysis oftitanium tetrabutoxide in the presence of HC1. The composition and microstructure of the resultingsamples are studied by XRD and TEM. These results show that the range of particle size of TiO_2 isfrom 20 to 30 nm. The mechanism of TiO_2 photocatalysis reaction has been discussed extensively.Photocatalytic activities of nanometer TiO_2 are also evaluated by degradation of the crystal violetsolution. Experimental results indicate that the synergistic action of H_2O_2 and ultrasonic wavegreatly enhances photo-catalytic reaction of TiO_2.展开更多
GaN-based continuous-wave operated blue-violet laser diodes(LDs) with long lifetime are demonstrated, which are grown on a c-plane GaN substrate by metal organic chemical vapor deposition with a 10 × 600 μm^2 ri...GaN-based continuous-wave operated blue-violet laser diodes(LDs) with long lifetime are demonstrated, which are grown on a c-plane GaN substrate by metal organic chemical vapor deposition with a 10 × 600 μm^2 ridge waveguide structure.The electrical and optical characteristics of a blue-violet LD are investigated under direct-current injection at room temperature(25 °C). The stimulated emission wavelength and peak optical power of the LD are around 413 nm and over 600 mW, respectively.In addition, the threshold current density and voltage are as small as 1.46 kA/cm^2 and 4.1 V, respectively. Moreover, the lifetime is longer than 1000 hours under room-temperature continuous-wave operation.展开更多
Herein,palygorskite（PAL）was activated via a simple hydrothermal process in the presence of ammonium sulfide,and the effects of activation on the microstructure,physico-chemical feature and adsorption behaviors of PA...Herein,palygorskite（PAL）was activated via a simple hydrothermal process in the presence of ammonium sulfide,and the effects of activation on the microstructure,physico-chemical feature and adsorption behaviors of PAL were intensively investigated.The hydrothermal process evidently improved the dispersion of PAL crystal bundles,increased surface negative charges and built more active –Si–O-groups served as the new＂adsorption sites＂.The adsorption property of the activated PAL for Methyl Violet（MV）was systematically investigated by optimizing the adsorption variables,including p H,ionic strength,contact time and initial MV concentration.The activated PAL exhibited a superior adsorption capability to the raw PAL for the removal of MV（from 156.05 to 218.11 mg/g）.The kinetics for MV adsorption followed pseudo second-order kinetic models,while the isotherm and thermodynamics results showed that the adsorption pattern well followed the Langmuir model.The structure analysis of PAL before and after adsorption demonstrated that electrostatic interaction and chemical association of –X–O-are the prominent driving forces for the adsorption process.展开更多
Molecularly imprinted polymers （MIPs） were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cr...Molecularly imprinted polymers （MIPs） were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cross-linker, respectively. Sys- tematic investigations of synthetic conditions were conducted. The surface morphology and recognition mechanism of the obtained polymers were studied using scanning electron microscope and spectrophotometric analysis. MIPs showed high atTmity to template molecule and were successfully applied as special solid-phase extraction sorbent for selective extraction of crystal violet from natural seawater. An off-line molecularly imprinted solid-phase extraction （MISPE） method followed by high-performance liquid chroma- tography with diodearray detection for the analysis of crystal violet was also established. MISPE columns have good recoveries for crystal violet standard solutions and good linearity was obtained over the concentration range of 0-200 ~tg L-1 （R2 〉 0.99）. Finally, two natural seawater samples were investigated. The recoveries of spiked seawater on the MISPE columns were from 44.47% to 62.34%, the relative standard deviation （n=3） being in the range of 2.89%-5.96%.展开更多
The upper waveguide （UWG） has direct influences on the optical and electrical characteristics of the violet laser diode （LD） by changing the optical field distribution or barrier of the electron blocking layer （...The upper waveguide （UWG） has direct influences on the optical and electrical characteristics of the violet laser diode （LD） by changing the optical field distribution or barrier of the electron blocking layer （EBL）. In this study, a series of InGaN-based violet LDs with different UWGs are investigated systematically with LASTIP software. It is found that the output light power （OLP） under an injecting current of 120 mA or the threshold current （Ith） is deteriorated when the UWG is u-In0.02Ga0.98N/GaN or u-In0.02Ga0.98N/AlxGa1-xN （0 ≤ x ≤ 0.1）, which should be attributed to small optical confinement factor （OCF） or severe electron leakage. Therefore, a new violet LD structure with u-In0.02Ga0.98N/GaN/Al0.05Ga0.95N multiple layer UWG is proposed to reduce the optical loss and increase the barrier of EBL. Finally, the output light power under an injecting current of 120 mA is improved to 176.4 mW.展开更多
Different preparation routes for TiO_(2)-supported natural and synthetic clinoptilolite(TiO_(2)/CP)composites were thoroughly investigated on the basis of sol-gel,hydrothermal,and in-situ hydrothermal methods.The micr...Different preparation routes for TiO_(2)-supported natural and synthetic clinoptilolite(TiO_(2)/CP)composites were thoroughly investigated on the basis of sol-gel,hydrothermal,and in-situ hydrothermal methods.The micro-structural features and physicochemical properties of resultant TiO_(2)/CPs were characterized via X-ray diffraction patterns,scanning(transmission)electron microscope images,Fourier transform infrared spectra,inductively coupled plasma-optical emission spectrometry methods,BET-isotherms,UV-visible spectra,and surface charge potential distributions.The results showed that in-situ hydrothermal method led to well dispersions of loaded-TiO_(2) particles on the surface of leaf-like CP,while obviously aggregated TiO_(2) on a relatively distorted structure of CP was obtained using sol-gel and hydrothermal methods.Their adsorptive and photocatalytic efficiencies for removal of crystal violet(CV)dye in aqueous solution were also explored under UV-irradiations.The results demonstrated that TiO_(2)/CPs synthesized via sol-gel and in-situ hydrothermal methods presented the excellent performances with 98% removal efficiencies as compare to the bare commercial TiO_(2) which achieved 53%removal of CV dye.While,the in-situ hydrothermally synthesized TiO_(2)/CPs were the best due to their moderate energy cost,highest adsorption capacities and removal efficiencies.Particularly,the synthetic CPs as supports exhibited synergetic photocatalytic activities for the degradation of CV dye,which is attributed to their high surface areas,better adsorption capability,and fine dispersion of TiO_(2) particles.Adsorption and degradation kinetics of CV dye were found to follow the pseudo-second and pseudo-first order models,respectively.展开更多
Blue-violet light can not only enhance the total content of biomass and glucoside but also enrich the taste of the fruit.Thus,it is meaningful to study the blue-violet luminescent materials for plant cultivation.In th...Blue-violet light can not only enhance the total content of biomass and glucoside but also enrich the taste of the fruit.Thus,it is meaningful to study the blue-violet luminescent materials for plant cultivation.In this study,titanium(IV)-activated CaYAlO4(CYAO) phosphors were synthesized by conventional hightemperature solid-state reaction.X-ray powder diffraction was employed to analyze the crystalstructure of CYAO.It is found that the doped Ti^4+ ions do not change obviously the crystal structure of phosphors.Upon 246 nm excitation,CaYAl1-xO4:xTi^4+phosphors exhibit broad blue-violet emission band peaking at 395 nm,which can be attributed to the charge transfer of Ti^4+-O^2-.Moreover,this phosphor exhibits strong thermal stability.The luminescence emission intensity at 150℃maintained about 91 mol% of its initial value at room temperature.Additionally,the electron transition process and concentration quenching mechanism of CaYAl1-xO4:xTi^4+are discussed in detail.The excellent luminescent properties indicate that CaYAl1-xO4:xTi^4+phosphor may have promising application in indoor plant cultivation.展开更多
Two dimensional(2D)materials are promising gas sensing materials,but the most of them need to be heated to show promising sensing performance.Sensing structures with high sensing performance at room-temperature are ur...Two dimensional(2D)materials are promising gas sensing materials,but the most of them need to be heated to show promising sensing performance.Sensing structures with high sensing performance at room-temperature are urgent.Here,another 2D material,violet phosphorus(VP)nanoflake is investigated as gas sensing material.The VP nanoflakes have been effectively ablated to have layers of 1–5 layers by laser ablation in glycol.The VP nanoflakes are combined with graphene to form VP/G heterostructuresbased NO sensor.An ultra-high gauge factor of 3×10^(7)for ppb-level sensing and high resistance response of 59.21%with ultra-short recovery time of 6s for ppm-level sensing have been obtained.The sensing mechanism is also analysed by density functional theory(DFT)calculations.The adsorption energy of VP/G is calculated to be-0.788 e V,resulting in electrons migration from P to N to form a P-N bond in the gap between VP and graphene sheet.This work provides a facile approach to ablate VP for mass production.The as-produced structures have also provided potential gas sensors with ultrasensitive performance as ppb-level room-temperature sensors.展开更多
Optical limiting properties of a crystal violet cation fulleride salt dissolved in tetrahydrofuran have been studied by using 10 ns,532 nm laser pulses.The fluence-dependent transmissivity measurements were performed ...Optical limiting properties of a crystal violet cation fulleride salt dissolved in tetrahydrofuran have been studied by using 10 ns,532 nm laser pulses.The fluence-dependent transmissivity measurements were performed on the samples with the same concentration and different path lengths in a collimated optical set-up.For comparison,the fluence-dependent transmissivities of fullerene C_(60) and crystal violet solutions were also measured under the same linear transmissivity.The nonlinear optical limiting effect of the fulleride salt in tetrahydrofuran was even slightly stronger than that of C_(60) in toluene.展开更多
A novel method was developed for enrichment and separation of trace mercury using phenolphthalein modified by ethyl violet （EV）. The effects of different parameters, such as stirring time, various metal ions and sal...A novel method was developed for enrichment and separation of trace mercury using phenolphthalein modified by ethyl violet （EV）. The effects of different parameters, such as stirring time, various metal ions and salts, and the amounts of phenolphthalein, NH4SCN, and EV on the extraction rate of mercury were studied, to select the experimental conditions. Under optimum conditions, mercury can be adsorbed on the surface of microcrystalline phenolphthalein by the intermolecular acdon strength. The possible reaction mechanism for the enrichment of mercury was discussed in detail. Hg（Ⅱ） could be completely separated from Fe（Ⅱ）, Co（Ⅱ）, Ni（Ⅱ）, Mn（Ⅱ）, Cd（Ⅱ）, Cr（Ⅲ）, and Al（Ⅲ） in the solution. The proposed method has been successfully applied to the determination of trace mercury in industrial wastewater with the recoveries above 99%. The relative standard deviation for five replicate determinations of 0.04 μg·mL^-1 of Hg（Ⅱ） was found to be 1.4%, 1.1%, and 1.2%, respectively. The analytical results were very satisfactory.展开更多
Recently ozone is one of natural hazards which comes from cars, industry using ozone for sterilization of organic and inorganic materials and for water purification. So, ozone sensing becomes very important, and conve...Recently ozone is one of natural hazards which comes from cars, industry using ozone for sterilization of organic and inorganic materials and for water purification. So, ozone sensing becomes very important, and convenient and accurate ozone sensor is required. A new high sensitivity ozone sensing system using an deep ultra-violet light emitting diode (DUV-LED) operated at the wavelength of 280 nm has been successfully constructed. The fabrication of diode operated at 280 nm is much easier than that of DUV-LED operated at Hg lamp wavelength of 254 nm. The system is compact and possible to sense the ozone concentration less than 0.1 ppm with an accuracy of 0.5% easily with low power DUV-LED of around 200 micro Watts operated at 280 nm without any data processing circuit.展开更多
The influences of InGaN/GaN multiple quantum wells (MQWs) and AlGaN electron-blocking layers (EBL) on the performance of GaN-based violet laser diodes are investigated. Compared with the InGaN/GaN MQWs grown at two di...The influences of InGaN/GaN multiple quantum wells (MQWs) and AlGaN electron-blocking layers (EBL) on the performance of GaN-based violet laser diodes are investigated. Compared with the InGaN/GaN MQWs grown at two different temperatures, the same-temperature growth of InGaN well and GaN barrier layers has a positive effect on the threshold current and slope efficiency of laser diodes, indicating that the quality of MQWs is improved. In addition, the performance of GaN laser diodes could be further improved by increasing Al content in the AlGaN EBL due to the fact that the electron leakage current could be reduced by properly increasing the barrier height of AlGaN EBL. The violet laser diode with a peak output power of 20 W is obtained.展开更多
基金The National Natural Science Foundation of China(12274055)the Fundamental Research Funds for the Central Universities(04442024072)the Training Program of Innovation and Entrepreneurship for Undergraduates in Dalian Minzu University(202312026063)。
文摘This article presented a facile fabrication process for polydimethylsiloxane(PDMS)composite gold nanotris⁃octahedra(Au NTOH)for a flexible SERS sensor with high sensitivity.Specifically,Au NTOH with excellent SERS behaviors was synthesized using a seed-mediated growth method and the dimensions of the Au NTOH was easily tuned.In addition,the influence of size on the SERS performance of their monolayers was systematically investigated,and the Au NTOH with the size of 61 nm possessed the best SERS performance.Importantly,a hydrophilic-substrateassisted interfacial self-assembled monolayer transfer technique was proposed to transfer Au NTOH onto PDMS films,resulting in forming flexible and transparent Au NTOH@PDMS substrates.Furthermore,the excellent signal homoge⁃neity of this substrate was demonstrated and the sensitivity was verified by a measurement of crystal violet(CV)as low as 1×10^(-8) mol/L.As a result,this SERS sensor is progressing for applying in the identification of trace contaminants in broad fields.
文摘In the current study novel magnetic BiOBr-Gd^(3+)doped CoFe_(2)O_(4)heterojunction nanocomposites fabricated by chemical precipitation method for Acid Violet 7(AV 7)and Reactive Red 120(RR 120)dye degradation under sunlight are presented.The samples were well characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM),scanning electron microscopy(SEM),energy dispersive X-ray analysis(EDAX),UV-visible near infrared(NIR),photoluminescence(PL),TRF,EIS,Mott-Schottky,and BET analysis.X-ray diffractograms of BiOBr-Gd^(3+)doped CoFe_(2)O_(4)nanocomposites authenticate the formation of the composite composed of diffraction peaks of both BiOBr and Gd^(3+)doped CoFe_(2)O_(4)samples.Photoluminescence(PL),Time Resolved Fluorescence Spectrocopy(TRF)and Electrochemical Impedance Spectroscopy(EIS)investigations were explored to examine the transfer efficiency of photoinduced charge carriers.Among the synthesized materials,the BiOBr-Gd^(3+)doped CoFe_(2)O_(4)-2 nanocomposite presents superior degradation capability for RR 120 of 87.34%and AV 7 dyes of 98.41%.The apparent rate constant(k)value of 0.1317 min^(-1)for AV 7 is sixteen times higher and RR 120(0.0135 min^(-1))is 2 times higher than pristine BiOBr.The radical trapping experiments also proved the role of photogenerated h^(+),O_(2)·^(-),and·OH radicals in the degradation mechanism.The superior performance of BiOBr-Gd^(3+)doped CoFe_(2)O_(4)-2 is ascribed to the formation of the heterostructure,the in-built electric field,and energy-band alignment,which thermodynamically and kinetically favors the photoactivity and stability of the heterojunction.
基金supported by National Natural Science Foundation of China(No.51902250).
文摘The crossmodal interaction of different senses,which is an important basis for learning and memory in the human brain,is highly desired to be mimicked at the device level for developing neuromorphic crossmodal perception,but related researches are scarce.Here,we demonstrate an optoelectronic synapse for vision-olfactory crossmodal perception based on MXene/violet phosphorus(VP)van der Waals heterojunctions.Benefiting from the efficient separation and transport of photogenerated carriers facilitated by conductive MXene,the photoelectric responsivity of VP is dramatically enhanced by 7 orders of magnitude,reaching up to 7.7 A W^(−1).Excited by ultraviolet light,multiple synaptic functions,including excitatory postsynaptic currents,pairedpulse facilitation,short/long-term plasticity and“learning-experience”behavior,were demonstrated with a low power consumption.Furthermore,the proposed optoelectronic synapse exhibits distinct synaptic behaviors in different gas environments,enabling it to simulate the interaction of visual and olfactory information for crossmodal perception.This work demonstrates the great potential of VP in optoelectronics and provides a promising platform for applications such as virtual reality and neurorobotics.
基金supported by the Scientific Research Fund of Hunan Provincial Education Department (No.10C1118)the Science and Technology Project of Hunan Province (No. 2009FJ3041)+2 种基金the Project of Natural Science Foundation of Hunan Province (No. 10JJ6053)the Ecological Key Discipline Open Fund of Hunan Province (No.JSS200901)the Project of National Natural Science Foundation of China (No. 31100370)
文摘A biosorbent prepared from powdered mycelial biomass of Ceriporia lacerata （CLB）, a basidiomycetous fungus, was applied for the uptake of Crystal Violet from aqueous solution. A batch adsorption experiment was used for the biosorption process, involving effect of experimental factors and biosorption kinetics and equilibrium. Biosorption process showed that the removal of Crystal Violet by CLB was effective over wide pH range, and meanwhile was independent on ionic strength. Biosorption capacities of CLB increased with the initial dye concentration increasing, due to an increase in the driving force of the concentration gradient. The adsorbed Crystal Violet amount per unit biomass weight decreased with increasing biosorbent dosage, due to the splitting effect of flux （concentration gradient） between sorbate and biosorbent. A maximum sorption capacity of 239.25 mg/g was observed. Biosorption kinetics was found to be best represented by the pseudo second-order kinetic model. The equilibrium adsorption data was well described by the Koble-Corrigan model. FT-IR （Fourier Transform Infrared Spetroscopy） spectrum showed the presence of O–H, COOH, C=O, C–N, C–H, –NH2 and P–OH in the surface of CLB as functional groups. This study showed CLB can effectively remove CV from dye wastewater.
基金supported by the Western Action Project of Chinese Academy of Science (No.KGCX2-YW-501)the Taihu Project of Jiangsu Provincial Science and Technology Office (No.BS2007118,BE2008087)the Key Laboratory of Resources and Environment Chemistry of West China,Hexi University(No.XZ0606)
文摘The adsorption of Methyl Violet （MV） cationic dye from aqueous solution was carried out by using crosslinked poly （acrylic acid-coacrylamide）/attapulgite （Poly（AA-co-AM）/ATP） composite as adsorbent. The factors influencing adsorption capacity of the composite such as pH, concentration of the dye, temperature, contact time, adsorbent dosage, ionic strength and surfactant were systematically investigated. The equilibrium data fitted very well to the Langmuir isotherm and the maximum adsorption capacity reached 1194 mg/g at 30℃. The thermodynamic parameters including △G0, △H0 and △S0 for the adsorption processes of MV on the composite were also calculated, and the negative △H0 and △G0 confirmed that the adsorption process was exothermicand spontaneous. The kinetic studies showed that the adsorption process was consistent with the pseudo second-order kinetic model and the desorption studies revealed that the regeneration of the composite adsorbent can be easily achieved.
基金supported by the National Natural Science Foundation of China(No.10864001)the Foundation of Science and Technology Department of Yunnan province(No.2005PY01-51)
文摘Highly active, stable and affordable surface enhanced Raman scattering （SERS） substrates were obtained by electrolyzing a mixture of AgNO3 （4 × 10^-4 mol/L） and Na3C6H5OTH2O （6 × 10^-5 mol/L） for 1, 2, 3 and 4 h at 7 V. With crystal violet （CV） as a test molecule, a portable Raman spectrometer with 785 nm laser excitation was employed to carry out the SERS detection. Colloidal Ag nanoparticles prepared by electrolyzing for 3 h with the particle size of （65 ±17） nm is a perfect SERS substrate for the ultratrace detection of CV, which displayed an enhancement factor of ca. 1.3 × 10^8 and the detection limit of CV is down to ca. 10-15 mol/L （ca. 10^-4 ppb） with 10^-1 mol/L KBr as aggregating agent. Thus, this SERS substrate will provide a hopeful foreground in ultratrace detection. Meanwhile, it will provide a possibility to bring Raman analysis out of the laboratory to process in situ, real-time detection and identification.
文摘Agrobacterium radiobacter MTCC 8161 completely decolorized the Crystal Violet with 8 hr （10 mg/L） at static anoxic conditions. The decreased decolorization capability by A. radiobacter was observed, when the Crystal Violet concentration was increased from 10 to 100 mg/L. Semi-synthetic medium containing 1% yeast extract and 0.1% NH4C1 has shown 100% decolorization of Crystal Violet within 5 hr. A complete degradation of Crystal Violet by A. radiobacter was observed up to 7 cycles of repeated addition （10 rag/L）. When the effect of increasing inoculum concentration on decolorization of Crystal Violet （100 mg/L） was studied, maximum decolorization was observed with 15% inoculum concentration. A significant increase in the activities of laccase （184%） and aminopyrine N-demethylase （300%） in cells obtained after decolorization indicated the involvement of these enzymes in decolorization process. The intermediates formed during the degradation of Crystal Violet were analyzed by gas chromatography and mass spectroscopy （GC/MS）. It was detected the presence of N,N,N＇,N＂-tetramethylpararosarfiline, IN, N-dimethylaminophenyl] [N-methylaminophenyl] benzophenone, N, N-dimethylaminobenzaldehyde, 4-methyl amino phenol and phenol. We proposed the hypothetical metabolic pathway of Crystal Violet biodegradation by A. radiobacter. Phytotoxicity and microbial toxicity study showed that Crystal Violet biodegradation metabolites were less toxic to bacteria （A. radiobacter, P. aurugenosa and A. vinelandii） contributing to soil fertility and for four kinds of plants （Sorghum bicolor, Vigna radiata, Lens culinaris and Triticum aestivum） which are most sensitive, fast growing and commonly used in Indian agriculture.
基金the Ministry of Environment and Forests (MOEF), New Delhi, for the financial support through research grant No.315-F-36, F. No. 19/9/2007-RE
文摘Fe（III） immobilized fire clay （Fe-FC） was prepared using ferric nitrate by solid state dispersion method and this hetero-Fenton catalyst was applied for the degradation of Acid Violet 7 （AV 7） under natural sunlight. The 26% ferric nitrate loaded fire clay was found to be most efficient. The experimental conditions such as solution pH, H2O2 concentration for efficient degradation of AV 7 have been determined. Unlike Fenton catalyst, Fe-FC is photoactive over a wide pH range of 3-7. This catalyst was found to be stable and reusable. The GC-MS analysis of experimental solutions during irradiation revealed the formation of 2,8-diaminonaphthalene-1,3,6- triol, 8-aminonaphthalene-1,2,3,6-tetrol, 2-aminonaphthalene-1,3,6,8-tetrol and 2-aminobenzene-1,3-diol/5-aminonbenzene-1,3-diol/ 2-aminobenzene-1,4-diol as intermediates. The 26% ferric nitrate loaded fire clay was characterized by XRD, ICP-AES, BET surface area, FT-IR, SEM-EDS and UV-DRS studies.
文摘TiO_2 nanoparticles with different phases are prepared by hydrolysis oftitanium tetrabutoxide in the presence of HC1. The composition and microstructure of the resultingsamples are studied by XRD and TEM. These results show that the range of particle size of TiO_2 isfrom 20 to 30 nm. The mechanism of TiO_2 photocatalysis reaction has been discussed extensively.Photocatalytic activities of nanometer TiO_2 are also evaluated by degradation of the crystal violetsolution. Experimental results indicate that the synergistic action of H_2O_2 and ultrasonic wavegreatly enhances photo-catalytic reaction of TiO_2.
基金supported by the National Key R&D Program of China (Nos. 2016YFB0401801, 2016YFB0400803)the Science Challenge Project (No. TZ2016003)+1 种基金the National Natural Science Foundation of China (Nos. 61674138, 61674139, 61604145, 61574135, 61574134, 61474142, 61474110)the Beijing Municipal Science and Technology Project (No. Z161100002116037)
文摘GaN-based continuous-wave operated blue-violet laser diodes(LDs) with long lifetime are demonstrated, which are grown on a c-plane GaN substrate by metal organic chemical vapor deposition with a 10 × 600 μm^2 ridge waveguide structure.The electrical and optical characteristics of a blue-violet LD are investigated under direct-current injection at room temperature(25 °C). The stimulated emission wavelength and peak optical power of the LD are around 413 nm and over 600 mW, respectively.In addition, the threshold current density and voltage are as small as 1.46 kA/cm^2 and 4.1 V, respectively. Moreover, the lifetime is longer than 1000 hours under room-temperature continuous-wave operation.
基金supported by the“863”Project of the Ministry of Science and Technology,People's Republic of China(No.2013AA032003)the National Natural Science Foundation of China(No.51403221)
文摘Herein,palygorskite（PAL）was activated via a simple hydrothermal process in the presence of ammonium sulfide,and the effects of activation on the microstructure,physico-chemical feature and adsorption behaviors of PAL were intensively investigated.The hydrothermal process evidently improved the dispersion of PAL crystal bundles,increased surface negative charges and built more active –Si–O-groups served as the new＂adsorption sites＂.The adsorption property of the activated PAL for Methyl Violet（MV）was systematically investigated by optimizing the adsorption variables,including p H,ionic strength,contact time and initial MV concentration.The activated PAL exhibited a superior adsorption capability to the raw PAL for the removal of MV（from 156.05 to 218.11 mg/g）.The kinetics for MV adsorption followed pseudo second-order kinetic models,while the isotherm and thermodynamics results showed that the adsorption pattern well followed the Langmuir model.The structure analysis of PAL before and after adsorption demonstrated that electrostatic interaction and chemical association of –X–O-are the prominent driving forces for the adsorption process.
基金supported by the Natural Science Foundation of China (41076065)the Major State Basic Research Development Program of China (973 Program) (2010CB428701)
文摘Molecularly imprinted polymers （MIPs） were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cross-linker, respectively. Sys- tematic investigations of synthetic conditions were conducted. The surface morphology and recognition mechanism of the obtained polymers were studied using scanning electron microscope and spectrophotometric analysis. MIPs showed high atTmity to template molecule and were successfully applied as special solid-phase extraction sorbent for selective extraction of crystal violet from natural seawater. An off-line molecularly imprinted solid-phase extraction （MISPE） method followed by high-performance liquid chroma- tography with diodearray detection for the analysis of crystal violet was also established. MISPE columns have good recoveries for crystal violet standard solutions and good linearity was obtained over the concentration range of 0-200 ~tg L-1 （R2 〉 0.99）. Finally, two natural seawater samples were investigated. The recoveries of spiked seawater on the MISPE columns were from 44.47% to 62.34%, the relative standard deviation （n=3） being in the range of 2.89%-5.96%.
基金Project supported by the National Key R&D Program of China(Grant Nos.2016YFB0400803 and 2016YFB0401801)the National Natural Science Foundation of China(Grant Nos.61674138,61674139,61604145,61574135,61574134,61474142,61474110,61377020,and 61376089)+1 种基金the Science Challenge Project,China(Grant No.TZ2016003)the Beijing Municipal Science and Technology Project,China(Grant No.Z161100002116037)
文摘The upper waveguide （UWG） has direct influences on the optical and electrical characteristics of the violet laser diode （LD） by changing the optical field distribution or barrier of the electron blocking layer （EBL）. In this study, a series of InGaN-based violet LDs with different UWGs are investigated systematically with LASTIP software. It is found that the output light power （OLP） under an injecting current of 120 mA or the threshold current （Ith） is deteriorated when the UWG is u-In0.02Ga0.98N/GaN or u-In0.02Ga0.98N/AlxGa1-xN （0 ≤ x ≤ 0.1）, which should be attributed to small optical confinement factor （OCF） or severe electron leakage. Therefore, a new violet LD structure with u-In0.02Ga0.98N/GaN/Al0.05Ga0.95N multiple layer UWG is proposed to reduce the optical loss and increase the barrier of EBL. Finally, the output light power under an injecting current of 120 mA is improved to 176.4 mW.
基金This work was supported by the National Natural Science Foundation of China (21878006)。
文摘Different preparation routes for TiO_(2)-supported natural and synthetic clinoptilolite(TiO_(2)/CP)composites were thoroughly investigated on the basis of sol-gel,hydrothermal,and in-situ hydrothermal methods.The micro-structural features and physicochemical properties of resultant TiO_(2)/CPs were characterized via X-ray diffraction patterns,scanning(transmission)electron microscope images,Fourier transform infrared spectra,inductively coupled plasma-optical emission spectrometry methods,BET-isotherms,UV-visible spectra,and surface charge potential distributions.The results showed that in-situ hydrothermal method led to well dispersions of loaded-TiO_(2) particles on the surface of leaf-like CP,while obviously aggregated TiO_(2) on a relatively distorted structure of CP was obtained using sol-gel and hydrothermal methods.Their adsorptive and photocatalytic efficiencies for removal of crystal violet(CV)dye in aqueous solution were also explored under UV-irradiations.The results demonstrated that TiO_(2)/CPs synthesized via sol-gel and in-situ hydrothermal methods presented the excellent performances with 98% removal efficiencies as compare to the bare commercial TiO_(2) which achieved 53%removal of CV dye.While,the in-situ hydrothermally synthesized TiO_(2)/CPs were the best due to their moderate energy cost,highest adsorption capacities and removal efficiencies.Particularly,the synthetic CPs as supports exhibited synergetic photocatalytic activities for the degradation of CV dye,which is attributed to their high surface areas,better adsorption capability,and fine dispersion of TiO_(2) particles.Adsorption and degradation kinetics of CV dye were found to follow the pseudo-second and pseudo-first order models,respectively.
基金supported by the National Natural Science Foundation of China(21706060,51703061)Natural Science Foundation of Hunan Province(2017JJ3103)+1 种基金Youth Project of Hunan Education Department(17B1118)Hunan Provincial Engineering Technology Research Center for Optical Agriculture(2018TP2003).
文摘Blue-violet light can not only enhance the total content of biomass and glucoside but also enrich the taste of the fruit.Thus,it is meaningful to study the blue-violet luminescent materials for plant cultivation.In this study,titanium(IV)-activated CaYAlO4(CYAO) phosphors were synthesized by conventional hightemperature solid-state reaction.X-ray powder diffraction was employed to analyze the crystalstructure of CYAO.It is found that the doped Ti^4+ ions do not change obviously the crystal structure of phosphors.Upon 246 nm excitation,CaYAl1-xO4:xTi^4+phosphors exhibit broad blue-violet emission band peaking at 395 nm,which can be attributed to the charge transfer of Ti^4+-O^2-.Moreover,this phosphor exhibits strong thermal stability.The luminescence emission intensity at 150℃maintained about 91 mol% of its initial value at room temperature.Additionally,the electron transition process and concentration quenching mechanism of CaYAl1-xO4:xTi^4+are discussed in detail.The excellent luminescent properties indicate that CaYAl1-xO4:xTi^4+phosphor may have promising application in indoor plant cultivation.
基金the funding support by National Natural Science Foundation of China(Nos.61705125,22175136)Open Foundation of State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures,Guangxi University(No.2022GXYSOF15)。
文摘Two dimensional(2D)materials are promising gas sensing materials,but the most of them need to be heated to show promising sensing performance.Sensing structures with high sensing performance at room-temperature are urgent.Here,another 2D material,violet phosphorus(VP)nanoflake is investigated as gas sensing material.The VP nanoflakes have been effectively ablated to have layers of 1–5 layers by laser ablation in glycol.The VP nanoflakes are combined with graphene to form VP/G heterostructuresbased NO sensor.An ultra-high gauge factor of 3×10^(7)for ppb-level sensing and high resistance response of 59.21%with ultra-short recovery time of 6s for ppm-level sensing have been obtained.The sensing mechanism is also analysed by density functional theory(DFT)calculations.The adsorption energy of VP/G is calculated to be-0.788 e V,resulting in electrons migration from P to N to form a P-N bond in the gap between VP and graphene sheet.This work provides a facile approach to ablate VP for mass production.The as-produced structures have also provided potential gas sensors with ultrasensitive performance as ppb-level room-temperature sensors.
基金Supported by the National Natural Science Foundation of China under Grant Nos.19525412,19974004 and 19884001the National Key Basic Research Special Foundation of China under Grant No.G1999075207.
文摘Optical limiting properties of a crystal violet cation fulleride salt dissolved in tetrahydrofuran have been studied by using 10 ns,532 nm laser pulses.The fluence-dependent transmissivity measurements were performed on the samples with the same concentration and different path lengths in a collimated optical set-up.For comparison,the fluence-dependent transmissivities of fullerene C_(60) and crystal violet solutions were also measured under the same linear transmissivity.The nonlinear optical limiting effect of the fulleride salt in tetrahydrofuran was even slightly stronger than that of C_(60) in toluene.
文摘A novel method was developed for enrichment and separation of trace mercury using phenolphthalein modified by ethyl violet （EV）. The effects of different parameters, such as stirring time, various metal ions and salts, and the amounts of phenolphthalein, NH4SCN, and EV on the extraction rate of mercury were studied, to select the experimental conditions. Under optimum conditions, mercury can be adsorbed on the surface of microcrystalline phenolphthalein by the intermolecular acdon strength. The possible reaction mechanism for the enrichment of mercury was discussed in detail. Hg（Ⅱ） could be completely separated from Fe（Ⅱ）, Co（Ⅱ）, Ni（Ⅱ）, Mn（Ⅱ）, Cd（Ⅱ）, Cr（Ⅲ）, and Al（Ⅲ） in the solution. The proposed method has been successfully applied to the determination of trace mercury in industrial wastewater with the recoveries above 99%. The relative standard deviation for five replicate determinations of 0.04 μg·mL^-1 of Hg（Ⅱ） was found to be 1.4%, 1.1%, and 1.2%, respectively. The analytical results were very satisfactory.
文摘Recently ozone is one of natural hazards which comes from cars, industry using ozone for sterilization of organic and inorganic materials and for water purification. So, ozone sensing becomes very important, and convenient and accurate ozone sensor is required. A new high sensitivity ozone sensing system using an deep ultra-violet light emitting diode (DUV-LED) operated at the wavelength of 280 nm has been successfully constructed. The fabrication of diode operated at 280 nm is much easier than that of DUV-LED operated at Hg lamp wavelength of 254 nm. The system is compact and possible to sense the ozone concentration less than 0.1 ppm with an accuracy of 0.5% easily with low power DUV-LED of around 200 micro Watts operated at 280 nm without any data processing circuit.
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFB0401801the National Natural Science Foundation of China under Grant Nos 61574135,61574134,61474142,61474110,61377020,61376089,and 61223005the One Hundred Person Project of the Chinese Academy of Sciences
文摘The influences of InGaN/GaN multiple quantum wells (MQWs) and AlGaN electron-blocking layers (EBL) on the performance of GaN-based violet laser diodes are investigated. Compared with the InGaN/GaN MQWs grown at two different temperatures, the same-temperature growth of InGaN well and GaN barrier layers has a positive effect on the threshold current and slope efficiency of laser diodes, indicating that the quality of MQWs is improved. In addition, the performance of GaN laser diodes could be further improved by increasing Al content in the AlGaN EBL due to the fact that the electron leakage current could be reduced by properly increasing the barrier height of AlGaN EBL. The violet laser diode with a peak output power of 20 W is obtained.
