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Highly efficient H2 production over NiCo2O4 decorated g-C3N4 by photocatalytic water reduction
摘要： Herein, ternary nickel cobalt oxide (NiCo2O4) was firstly employed to increase the photocatalytic water reduction ability of g-C3N4. 17.5wt%-NiCo2O4/g-C3N4 shows excellent water splitting performance with a H2 production rate of 5480 μmol·h-1·g-1, which is extremely better than that of Co3O4, NiO, Pt modified g-C3N4. The quantum efficiency of 17.5wt%-NiCo2O4/g-C3N4 can reach 4.5% under 400 (±7.5) nm light irradiation. The greatly increased activity of 17.5wt%-NiCo2O4/g-C3N4 can be attributed to the richer active sites and the superior electrical performance provided by co-existing nickel and cobalt ions with multivalent state. Moreover, the activity of composite almost shows no significant weaken even after 20 h irradiation. A Z-scheme route was put forwarded for H2 production over NiCo2O4/g-C3N4 instead of the traditional p-n junction based on our study.
关键词： NiCo2O4,bimetallic complex,photocatalysis,hydrogen evolution
更新于2025-09-23 15:23:52
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Photocatalytic hydrogen production by biomimetic indium sulfide using Mimosa pudica leaves as template
摘要： Biomimetic sulfur-deficient indium sulfide (In2.77S4) was synthesized by a template-assisted hydrothermal method using leaves of Mimosa pudica as a template for the first time. The effect of this template in modifying the morphology of the semiconductor particles was determined by physicochemical characterization, revealing an increase in surface area, decrease in microsphere size and pore size and an increase in pore volume density in samples synthesized with the template. X-ray photoelectron spectroscopy (XPS) analysis showed the presence of organic sulfur (S-O/S-C/S-H) and sulfur oxide species (eSO2, SO3^2-, SO4^2-) at the surface of the indium sulfide in samples synthesized with the template. Biomimetic indium sulfide also showed significant amounts of Fe introduced as a contaminant present on the Mimosa pudica leaves. The presence of these sulfur and iron species favors the photocatalytic activity for hydrogen production by their acting as a sacrificial reagent and promoting water oxidation on the surface of the templated particles, respectively. The photocatalytic hydrogen production rates over optimally-prepared biomimetic indium sulfide and indium sulfide synthesized without the organic template were 73 and 22 mmol g^-1 h^-1, respectively, indicating an improvement by a factor of three in the templated sample.
关键词： Photocatalytic hydrogen production,XPS analysis,In2.77S4,Template-assisted hydrothermal
更新于2025-09-23 15:23:52
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Highly efficient method for oxidation of dissolved hydrogen sulfide in water, utilizing a combination of UVC light and dissolved oxygen
摘要： Hydrogen sul?de is a hazardous contaminant that may appear in well-water and in sewage streams. Here we present a very e?cient way for the removal of H2S from well-water, based on combining UVC light and oxygen. The method was tested with H2S-enriched tap water as well as with natural well water, both of which containing up to 20 mg/L of H2S. A conversion of up to 90% was obtained within a residence time of no more than a few minutes. The quantum e?ciency, de?ned as the ratio between the number of removed H2S molecules to the number of impinging photons, was found to be as high as 70%, depending on conditions. The main product was found to be sulfate, without the appearance of elemental sulfur, i.e. with no major change in turbidity. The absence of sulfur in the outlet stream in of large importance when treating H2S-containing well-water, since it omits the need for posttreatment removal of particles. Results are explained by the excitation of HS- species, following by formation of polysul?de anions that readily react with any formed elemental sulfur, eventually yielding sulfate ions.
关键词： AOP,Water treatment,Sulfate,Hydrogen sul?de,Oxidation
更新于2025-09-23 15:23:52
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H-complexes in the “4-n-alkoxybenzoic acid: 4-pyridyl 4′-n-alkoxybenzoate” system. IR spectroscopy and quantum chemical calculations
摘要： IR spectra of individual 4-n-dodecyloxybenzoic acid (A) and 4-pyridyl 4'-n-dodecyloxybenzoate (B) compounds as well as IR spectra of 2A:1B and 1A:1B systems were recorded. For the assignment of the experimental vibrational spectra a series of quantum chemical calculations of DFT(B97-D)/6-311++G** level was carried out. Hydrogen-bonded complexes of types A···A, A···B, as well as various trimers that can be formed at different component ratios in system A-B were simulated. The geometric structure of these complexes was optimized and the vibrational frequencies were calculated. The conclusions on the molecular organization of system A-B for different ratios of the components A and B were based on the interpretation of IR spectra and the analysis of calculated thermodynamic characteristics of self-assembly processes. Thus, it is determined that the system A consists of cyclic A···Acycl dimers; in 1A:1B system the H-complexes of A···B type are formed. In the 2A:1B system in the process of self-assembly, instead of the complexes A···A···B and A···B···A of stoichiometric composition, the complexes A···B and A···Acycl are formed in the ratio 2:1. These results are confirmed by the dilatometric method data.
关键词： thermodynamic characteristics,4-pyridyl 4'-n-alkoxybenzoate,DFT,IR spectra,self-assembly,4-n-alkoxybenzoic acid,hydrogen bonded complexes
更新于2025-09-23 15:23:52
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Modulated anodization synthesis of Sn-doped iron oxide with enhanced solar water splitting performance
摘要： Modulated anodization synthesis is introduced here for the fabrication of porous Sn-doped iron oxide. Continuous square-wave modulation consisting of highly positive (+50 to +80 V range) and slightly negative potentials (-2 to -10 V range) at 100 Hz allowed the etching anodization of the metallic Fe foil and incorporation of Sn-dopant from the fluoride anion-containing electrolyte, respectively. Compared with the undoped iron oxide, the surface-enriched Sn-dopant (in the form of Sn4+) alleviates the trapping and recombination of surface holes, while enhancing the hole transfer at the surface states. As such, the overpotential for photoelectrochemical (PEC) water oxidation was reduced by 110 mV and photocurrent density doubled. The incorporation of Co-Pi co-catalyst further improved the hole transfer efficiency, resulting in further reduction in overpotential by another 330 mV with respect to the bare Sn-doped iron oxide and significant improvement in photocurrent density at potentials below +1.23 V vs. reversible hydrogen electrode. Lastly, the iron oxide electrodes exhibit highly stable PEC water oxidation with no degradation in activity throughout the 10 h assessment under simulated solar irradiation and Faradaic efficiency of 90%. We envisage that the modulated anodization technique can be conveniently incorporated for a wide range of other dopants in search of efficient solar water splitting electrodes.
关键词： Doping,Hematite,Hydrogen,Photoelectrochemical water splitting,Charge transport
更新于2025-09-23 15:23:52
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Electrochemiluminescent sensor based on Ru(bpy)32+-doped silica nanoprobe by incorporating a new co-reactant NBD-amine for selective detection of hydrogen sulfide
摘要： Here, we fabricated a new amine compound as the co-reactant and incorporated an ECL sensor based on RuSi NPs/Nafion to improve the detection sensitivity of ECL system toward H2S by enhancing ECL intensity. The prepared sensor shows a good detection effect. In the work, water-oil microemulsion method was used to synthesize the Ru(bpy)3 2+-doped silica nanoparticles (RuSi NPs), and then mixed the RuSi NPs solution with Nafion (5 wt%) followed by modifying the mixture to the electrode. Upon treatment with H2S, the co-reactant NBD (7-nitro-1,2,3-benzoxadiazole) can release the piperazine intermediate, which can effectively improve the ECL signals of Ru(bpy)3 2+. This enhanced ECL assay for H2S detection have the following several merits: excellent sensitivity with the detection limit of 1.7 × 10 -12mol/L, good selectivity over interfering species.
关键词： Co-reactant,ECL,NBD-amine,Hydrogen sulfide,Ru(bpy)3
更新于2025-09-23 15:23:52
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Photocathodic hydrogen evolution from catalysed nanoparticle films prepared from stable aqueous dispersions of P3HT and PCBM
摘要： Photo-assisted hydrogen evolution is achieved on photocathodes comprising of nanoparticles of poly(3-hexylthiophene) (npP3HT) and nanoparticles of phenyl-C61-butyric acid methyl ester (npPCBM) onto which ultra-low loadings of Pt nanoparticles are deposited. The nanoparticles, npP3HT and npPCBM, are prepared individually via miniemulsion using surfactants of opposite head group polarity. Aqueous dispersions of npP3HT:npPCBM, devoid of organic solvent, are cast conformally onto ITO-coated glass to yield water-insoluble bulk-heterojunction films. Pt is deposited photoelectrochemically onto ITO/npP3HT:npPCBM photocathodes and found to nucleate preferentially on PCBM nanoparticles. ITO/npP3HT:npPCBM/Pt photocathodes produce 65 μA/cm2 photocurrent under 100 mW/cm2 of visible light at 0.0 VSHE and liberate H2 gas. The photocurrents observed for electrodes prepared using npP3HT:npPCBM are twice as large, and the onset potential is ～0.4 V more positive than analogous photocathodes cast from nanoparticles each comprising an intimate blend of P3HT and PCBM. These are encouraging results for large scale synthesis of organic photoelectrochemical devices, given the simplicity of the photoelectrode, i.e., prepared from aqueous solutions and devoid of vacuum-deposited films such as charge transport layers and protective films.
关键词： Polymer nanoparticle,Photoelectrochemistry,P3HT: PCBM bulk-heterojunction,Solar hydrogen generation,Organic semiconductor,Mini-Emulsion
更新于2025-09-23 15:23:52
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Facile, rapid one-pot synthesis of multifunctional gold nanoclusters for cell imaging, hydrogen sulfide detection and pH sensing
摘要： In this study, we have developed a facile, rapid one-pot strategy for synthesis of orange fluorescent gold nanoclusters (MBISA–AuNCs) at room temperature by using 2-Mercapto-5-benzimidazolesulfonic acid (MBISA) as both reducing and protecting reagent. The prepared AuNCs exhibited prominent advantages including high fluorescent quantum yield, good water solubility, excellent biocompatibility and low toxicity. Based on these superior properties, the AuNCs have been multi-talented applied in cell imaging, hydrogen sulfide detection and pH sensing. Confocal fluorescence imaging showed that the MBISA–AuNCs could enter living cells and distribute in the cytoplasm. Additionally, the obtained AuNCs could visualize H2S fluctuations in living cells without interference of autofluorescence based on their high sensitivity and selectivity detection for H2S with a linear range of 2.7 × 10–11–8.5 × 10?4 M and a detection limit of 0.024 nM. Most strikingly, the AuNCs exhibited strong pH dependent behavior and responded linearly, rapidly and reversibly to minor pH fluctuations within the range of 2.01–12.00. Therefore, the AuNCs could also image pH fluctuations in live cells with negligible autofluorescence and provided a new method of analysis to visualize monitoring wide pH range change in live cells.
关键词： Cell imaging,pH sensor,Gold nanoclusters,Fluorescence,Hydrogen sulfide
更新于2025-09-23 15:23:52
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Photophysical Properties of Phthalimide and Pyromellitic Diimide Tethered Imidazolium Nitrophenolate Salts
摘要： Structural aspects of the salt of 2-(3-(1H-imidazol-1-yl)propyl) isoindoline-1,3-dione (L1) with 2,4,6-trinitrophenol as well as the salts of N,N’-bis(3-imidazol-1-yl-propyl)-pyromelliticdiimide (L2) with 2,4-dinitrophenol (H24dnp) and 2,4,6-trinitrophenol (H246tnp) are reported along with the solid and solution studies on the photophysical properties of these salts. The fluorescence emission of the L1 and L2 are quenched by H24dnp and H246tnp both in solid and in solution. In solution the L1 has comparable binding constant with H24dnp and H246tnp but the relative ability to quench the fluorescence emission of L1 by H24dnp is less than the quenching abilities of the H246tnp. These two nitrophenols independently do not distinguish the L1 from L2 but the extent of quenching caused independently by the H24dnp or H246tnp on L1 or L2 make them easily distinguishable. Addition of water quenches the fluorescence emission of L1 and L2; but the addition of water to solution of the nitrophenolate salts result in the recovery of fluorescence emissions from the quenched states. The salts in solid state have short emission life-times. The PET effect prominently caused by mineral acids on L1 or L2 is not observed in the nitrophenolate salts. In solid state the O-π interactions contributed to stacking of the aromatic in the 2,4,6-trinitrophenolate salt of L2, hence it is non-fluorescent.
关键词： Binding of imidazole,Charge-assisted hydrogen bonds,Fluorescence,Cyclic imide,Nitrophenol derivatives
更新于2025-09-23 15:23:52
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Solid-State Fluorescence-based Sensing of TATP via Hydrogen Peroxide Detection
摘要： Fluorenylboronate ester chromophore-based thin films were investigated for the detection of triacetone triperoxide (TATP) vapors via the decomposition product, hydrogen peroxide. Sensing with a high level of sensitivity was achieved using a fluorescence "turn-on" mechanism based on the significant shifts in the absorption and photoluminescence spectra that occurs when the boronate esters were converted to phenoxides by hydrogen peroxide under basic conditions. The addition of an organic base was found to be critical for achieving fast conversion reactions and the formation of the phenoxide anions. Addition of a nitrile group to the fluorenyl boronate ester moiety improved the stability of the material to photooxidation, increased the photoluminescence quantum yields, and enhanced the absorption and emission shifts to longer wavelengths. In real-time sensing measurements, films comprising the cyanofluorenyl boronate ester moiety and tetra-n-butylammonium hydroxide had a response time to acid-decomposed TATP vapor of seconds and a limit of detection of 40 ppb in 60 s.
关键词： fluorenylboronate ester,triacetone triperoxide,phenoxide,nitrile,fluorescence,hydrogen peroxide
更新于2025-09-23 15:23:52