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Light-Tuned DC Conductance of Anatase TiO2 Nanotubular Arrays: Features of Long-Range Charge Transport
摘要： Experimental results related to the photoactivated dc conductance of anatase TiO2 nanotubular arrays (aTNTAs) under pulsed irradiation by a laser light inside and outside the fundamental absorption band are presented. It is found that the mobility and diffusion coefficients of charge carriers in the examined aTNTA are extremely low due to a strong charge-phonon coupling, abundance of shallow traps, and hopping conductivity between adjacent nanotubes. We consider that the confining electric field appeared within the array structure due to the difference in the local concentrations of excess electrons and holes at large values of the dc conductance suppresses the drift current. In this case, the dc conductance of such aTNTAs is mainly matured by the diffusion of mobile carriers. A recurrent kinetic model for evolution of the dc conductance of aTNTAs under laser irradiation has been proposed to interpret the experimental results.
关键词： anatase nanotubes,laser irradiation,dc conductance,Urbach energy,drift current,inter-band transition,diffusion current,charge mobility
更新于2025-09-10 09:29:36
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Facile ionothermal synthesis of TiO2 nanorods for photocatalytic H2 generation
摘要： Facile ionothermal method has been employed to synthesize One-dimensional (1-D) mixed phase TiO2 nanorods (NRs) using ionic liquid as the reaction medium. The PXRD pattern reveals the formation of mixed phase TiO2 having 68.3% of anatase and 31.7% rutile phase with average crystallite size of ~ 10?nm. TEM images depict the average thickness of TiO2 NRs are in the range 50–100?nm. The 1-D mixed phase TiO2 NRs showed 5 times better hydrogen production activity than P-25 in the water-glycerol mixture under solar light irradiation. The reason could be the synergetic effect and unique optical properties of 1-D anatase–rutile TiO2 mixed-phase system.
关键词： solar light irradiation,TiO2 nanorods,mixed phase,ionothermal synthesis,photocatalytic H2 generation
更新于2025-09-10 09:29:36
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Increased nitrogen-vacancy centre creation yield in diamond through electron beam irradiation at high temperature
摘要： The nitrogen-vacancy (NV) centre is a fluorescent defect in diamond that is of critical importance for applications from ensemble sensing to biolabelling. Hence, understanding and optimising the creation of NV centres in diamond is vital for technological progress in these areas. We demonstrate that simultaneous electron irradiation and annealing of a high-pressure high-temperature diamond sample increases the NV centre creation efficiency from substitutional nitrogen defects by up to 117% with respect to a sample where the processes are carried out consecutively, but using the same process parameters. This increase in fluorescence is supported by visible and infrared absorption spectroscopy experiments. Our results pave the way for a more efficient creation of NV centres in diamond as well as higher overall NV densities in the future.
关键词： diamond,nitrogen-vacancy centre,high temperature,fluorescence,absorption spectroscopy,electron beam irradiation
更新于2025-09-10 09:29:36
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Assessment of focused multivector ultraviolet disinfection with shadowless delivery using 5-point multisided sampling of patient care equipment without manual-chemical disinfection
摘要： The aim of this study was to evaluate the performance of a focused multivector ultraviolet (FMUV) system employing shadowless delivery with a 90-second disinfection cycle for patient care equipment inside and outside the operating room (OR) suite without manual-chemical disinfection. A 5-point multisided sampling protocol was utilized to measure the microbial burden on objects inside and outside the OR environment in a 3-phase nonrandomized observational study. Surface sampling was performed pre- and postdisinfection in between cases (IBCs) to assess the performance of manual-chemical disinfection. FMUV system performance was separately assessed pre- and postdisinfection before the first case and IBCs. Additionally, visibly clean high-touch objects were sampled outside the OR, and the microbial burden reductions after FMUV disinfection were quantified without manual-chemical disinfection. Manual-chemical disinfection reduced the active microbial burden on sampled objects IBCs by 52.8%-90.9% (P < .05). FMUV reduced the active microbial burden by 92%-97.7% (P < .0001) before the first case and IBCs combined, and 96.3%-99.6% (P < .0001) on objects outside the OR without chemical disinfection. Five-point multisided sampling proved effective for assessing disinfection performance on all exterior sides of equipment. FMUV produced significant overall reductions of the microbial burden on patient care equipment in all study phases and independent of manual cleaning and chemical disinfection.
关键词： Disinfectants,Surface sampling techniques,Manual cleaning,Environmental disinfection,Ultraviolet germicidal irradiation,Infection prevention
更新于2025-09-10 09:29:36
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Controllable synthesis of flower-root shaped Bi2O3/Bi2MoO6 heterostructures as an efficient photocatalyst under visible light irradiation
摘要： In this article, Bi2O3/Bi2MoO6 composites were synthesized hydrothermally under optimized conditions, by adjusting pH, the concentration of polyvinylpyrrolidone (PVP (K30)) and reaction time. During the synthesis process, flower-root shaped zero-gap Bi2O3/Bi2MoO6 heterojunctions were successfully synthesized. The adopted samples were characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), Diffuse reflectance spectra (DRS), Photoluminescence (PL), and Fourier transform infrared spectroscopy (FT-IR). The photocatalytic activity was measured under visible-light-irradiation (λ > 420 nm) by degrading tetracycline (TC), ciprofloxacin (CPFX) (antibiotics) and rhodamine B (RhB), methylene blue (MB) (dangerous dyes). The degradation results indicated that photocatalyst sample synthesized at pH 9.0, PVP (K30) 0.05 mol/L and 80 min reaction time (Sup-Bi2O3/Bi2MoO6) demonstrated highly efficient performance. The Sup-Bi2O3/Bi2MoO6 showed the highest apparent rate constant (Kapp) that’s 50% more than the samples prepared at ordinary conditions. Photocatalytic degradation order was i.e. RhB> TC> CPFX> MB, which depends on the polarity of the degrading medium.
关键词： Bi2O3/Bi2MoO6,Flower-root shaped,Heterojunction,Visible light irradiation,Photocatalyst
更新于2025-09-10 09:29:36
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The effect of manganese doping on structural, optical, and photocatalytic activity of zinc oxide nanoparticles
摘要： In this work, polyethylene glycol-6000 (PEG-6000) capped ZnO nanoparticles (NPs) were synthesized by doping with varying levels of Mn (0, 1, 2, 3, and 4 wt.%; 0% implies no doping). The crystalline sizes of the hexagonal wurtzite-structured nanoparticles, when measured with (4%) and without Mn doping (0%), were 30 and 28 nm, respectively. The Mn doping led to a shift of the ZnO optical band gap from 3.36 to 3.51 eV. The Mn2+ ions from the doping agent caused tail states in the absorbance spectrum of ZnO NPs, allowing them to be used as effectual UV photocatalysts for the degradation of organic contaminants (e.g., methyl orange (MO), methylene blue (MB), and congo red (CR)). This effect was optimized when doped with 4% Mn. When comparing 0 and 4% Mn doping, the degradation efficiency of the three contaminants was approximately 87/93.5 (MO), 85/88 (MB), and 86/93 (CR)%, respectively. Accordingly, Mn doping on ZnO NPs was found to significantly enhance their photo-degradation efficiency.
关键词： Mn-ZnO,photocatalytic degradation,organic contaminants,UV irradiation,semiconductor nanoparticles
更新于2025-09-10 09:29:36
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Bandgap engineering of TiO2 nanoparticles through MeV Cu ions irradiation
摘要： The effect of 5 MeV Cu++ ions irradiation on structural and optical properties of Anatase TiO2 nanoparticles (TiO2-NPs) is investigated. For this purpose, TiO2-NPs are irradiated with different Cu++ ions ?uences, ranging from 1 (cid:1) 1015 to 1 (cid:1) 1016 ions/cm2 at room temperature. XRD results con?rm the Ti3O7 phase appear at the dose of 5 (cid:1) 1015 ions/cm2 and peak intensity of Ti3O7 phase gradually increases with an increase of Cu++ ions irradiation dose. At the dose of 1 (cid:1) 1016 ions/cm2 TiO2 Anatase phase were transformed to Rutile phase. Same observations are con?rmed from Raman spectroscopy. High resolution transmission electron microscopy (HRTEM) reveals that morphology converted into wavy shape and crystal structure detrioted with increase Cu ion irradiation dose to form vacancy loops and interstitial loops. Scanning electron microscopy (SEM) shows that TiO2-NPs have been fused to form a cluster of nanoparticles at high Cu ion beam dose, while bandgap of TiO2-NPs reduces from 3.19 eV to 2.96 eV as a function of Cu++ irradiation ?uence. These phase transformations and crystal damage are the responsible for optical bandgap reduction. The mechanism for the currently observed phase transformation of TiO2 and coalescence of TiO2-NPs are discussed in term of thermal spikes model.
关键词： Coalescence of NPs,Bandgap engineering,Cu++ irradiation,Rutile phase,TiO2 nanoparticles
更新于2025-09-10 09:29:36
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Light enhanced electrochemistry and electrochemiluminescence of luminol at glassy carbon electrodes
摘要： We report in this work the enhancement effect of light irradiation on the electrochemistry and electrochemiluminescence (ECL) of luminol at the bare glassy carbon electrode (GCE). Light irradiation on the GCE surface induced the formation of hot electron-hole pairs. In alkaline solutions, hot holes can oxidize hydroxide anions to hydroxyl radicals that are capable of promoting the oxidation of luminol to generate larger current and stronger ECL. Moreover, the stability of current and ECL is also significantly improved upon light irradiation. This study provides a simple method to enhance the electrochemistry and ECL of luminol that have promise in improving the sensitivity of luminol-based chemical analysis and bioanalysis.
关键词： light irradiation,electrochemiluminescence,glassy carbon electrode,luminol,hot hole
更新于2025-09-10 09:29:36
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Athermal coalescence of two parallel and contacting amorphous SiOx nanowires as induced by uniform e-beam irradiation
摘要： The coalescence of two parallel and contacting amorphous SiOx nanowires (a-SiOx NWs) as induced by uniform electron beam irradiation was in-situ studied at room temperature in a transmission electron microscope. It was observed that during the irradiation the two parallel and contacting nanowires exhibited a rapid athermal coalescence at and near the contacting surface and finally evolved into a single nanowire with a bigger diameter where the atom loss during the coalescence process was not observed. Based on the atom diffusion and plastic flow driven by the nanocurature of a-SiOx NWs, and the beam-induced athermal activation induced by the electron beam, a new mechanism was proposed to elucidate the experimental phenomena.
关键词： beam-induced athermal activation,nanocurvature,welding,diffusion,electron beam irradiation
更新于2025-09-10 09:29:36
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The potential use of the UV-A and UV-B to improve tomato quality and preference for consumers
摘要： Solanum lycopersicum L. is among the healthiest fruits/vegetables due to its richness in bioactive compounds. However, its fruits from off-season (usually obtained in greenhouses that block UV-rays) have lower reputation than the ones of in-season/field productions. We hypothesise that moderate UV-A/UV-B irradiation during fruit development is able to improve its bioactive compounds and sensorial attributes, increasing its healthy properties. We supplemented for 30 days ‘MicroTom’ fruiting plants with two daily doses of UV-A (1 or 4 h) and UV-B (2 or 5 min). Irradiated plants showed higher ripening synchronization and produced more and smaller fruits. UV-A irradiation stimulated the fruit’s antioxidant capacity, and the antiradical activity by the accumulation of phenolic compounds including the flavonoids. Only the UV-A1 h condition promoted the accumulation of ortho-diphenols in tomato fruits. Regarding the consumers’ preference for aroma/taste, a consumers’ panel test ranked the tomatoes as UV-A 1 h, UVA 4 h, Control, UV-B 5 min and UV-B 2 min. We conclude that the supplementation of UV-A during pre-harvest is particularly effective in increasing ripening synchronization and fruit’s nutritional properties, potentially making these fruits more appealing to consumers.
关键词： Nutritional value,Antioxidants,Pre-harvest-irradiation,Metabolism modulation,Phenolic compounds,Ultraviolet supplementation
更新于2025-09-10 09:29:36