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- 2018
- imgae sensor
- internet of things
- drone
- visible light ID
- Signal-to-Noise Ratio (SNR)
- Infinite Gain Multiple Feedback (IGMF)
- Visible Light Communications (VLC)
- LED
- Trans-Impedance Amplifier (TIA)
- Optoelectronic Information Science and Engineering
- Tohoku University
- University of Northumbria
- University of Huddersfield
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Visible-light-triggered generation of persistent radical anions from perylenediimides: A substituent effect and potential application in photocatalytic reduction of Ag+
摘要： Three perylenediimide derivatives were reduced to their persistent radical anions in N-methyl-2-pyrrolidone (NMP) under ambient conditions by a visible light photoinduced electron transfer (PET). UV?vis and electron paramagnetic resonance (EPR) measurements were carried out to confirm the formation of radicals. The relationships between molecular structure, electrochemical property, phototransformation kinetics, and air stability of radical anions were investigated by the introduction of pyrimidine rings at the core position and fluoroalkylation substituents at the imide position. This study reveals that the electron-deficient pyrimidine rings and electron-withdrawing fluoroalkylation substituents can effectively enhance the phototransformation rate and the radical stability at ambient conditions. The effects of solvents and illuminance levels on the photoinduced reduction of perylenediimides were also studied. A photocatalytic reduction of Ag+ was successfully carried out using the perylenediimide with pyrimidine and fluoroalkylation substituents as catalyst upon irradiation with visible light.
关键词： Photocatalytic reduction,Perylene diimide derivative,Silver ion,Persistent radical anion,Visible light irradiation
更新于2025-11-14 17:03:37
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Construction of a high-performance photocatalytic fuel cell (PFC) based on plasmonic silver modified Cr-BiOCl nanosheets for simultaneous electricity production and pollutant removal
摘要： The development of high-performance photocatalytic fuel cell (PFC) is seriously hampered by the poor light utilization rate and low charge carriers transfer efficiency. Herein, we have experimentally obtained the plasmonic Ag modified Cr-BiOCl (Cr-BOC/Ag) with high visible light photocatalytic activity and provided direct evidence for the substantially enhanced catalytic activity in metal-semiconductor photocatalysts. The experimental results revealed that the Cr doping and Ag modification could not only extend the photo absorption of BiOCl from the UV to the visible light region but also greatly increase the generation and transfer rate of charge carriers because of its narrowed band gap and the localized surface plasmon resonance (LSPR) effect of metallic Ag. Under visible light irradiation, the Cr-BOC/Ag showed the remarked enhancement on PFC performance when the optimum contents of Cr doping and Ag loading was 14.4% and 4%, respectively. The trapping experiments and multiple characterizations demonstrated that the advantageous combination of Cr doping effect and SPR effect induced by the Ag nanoparticles is responsible for the high generation rate of oxidative species and effective charge carriers transfer. By using RhB as fuel, approximately 75.1% color removal efficiency and 8.38% Coulombic efficiency were obtained under visible light irradiation for 240 min, which are higher than that of MO and TC. And, the Jsc and Voc of Cr-BOC/Ag photoanode were measured to be 0.0073 mA/cm2 and 0.543 V.
关键词： photocatalytic degradation,SPR,BiOCl,coulombic efficiency,visible light,fuel cell
更新于2025-11-14 17:03:37
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Preparation of Ag-doped Bi5O7I composites with enhanced visible-light-induced photocatalytic performance
摘要： A novel heterostructure photocatalysts, Ag-doped Bi5O7I composites (Ag/Bi5O7I), were synthesized by a simple hydrothermal method. Compared with Bi5O7I, Ag/Bi5O7I composites had a stronger light absorption in the visible and near-infrared region and the light absorption edge of Ag/Bi5O7I composites had a slight red shift. Moreover, Ag/Bi5O7I composites possessed a higher photocatalytic activity than Bi5O7I on the degradation of rhodamine B (RhB) and methyl orange (MO) under visible-light irradiation (λ ≥ 420 nm). When the content of Ag was 1%, the degradation efficiency of the Ag/Bi5O7I composites toward RhB and MO reached the maximum value, which was about 20.2 and 7.6 times higher than that of Bi5O7I, respectively. The trapping experiments shown that superoxide radicals and holes were the main active species in the photodegradation process. The excellent photocatalytic performance could be attributed to Ag/Bi5O7I heterojunction and surface plasma resonance effect of Ag, which could increase absorption of visible light and cause the efficient separation and migration of carriers.
关键词： Ag-doped Bi5O7I,Visible-light,Surface plasma resonance,Heterostructure photocatalysts
更新于2025-11-14 17:03:37
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2D visible-light-driven TiO2@Ti3C2/g-C3N4 ternary heterostructure for high photocatalytic activity
摘要： A novel 2D visible-light-driven TiO2@Ti3C2/g-C3N4 ternary heterojunction photocatalyst with modified interfacial microstructure and electronic properties was synthesized by ultrasonic-assisted calcination method. The remarkably active g-C3N4 could provide high productivity of photogenerated electrons and holes. Meanwhile, the O/OH-terminated Ti3C2 and by-product TiO2 could act as excellent supporters by migrating electrons in TiO2@Ti3C2/g-C3N4 hybrids. As a result, the highest photocatalytic activities in the degradation of aniline and RhB were increased to 5 and 1.33 times higher than that of pristine g-C3N4 under visible-light irradiation, respectively. Furthermore, we proposed that n–n heterojunction and n-type Schottky heterojunction were built up across their interfaces, which efficiently improve the transition of electrons and further promote the photocatalytic activity of TiO2@Ti3C2/g-C3N4 hybrids. More appealingly, all the results highlight that the environment-friendly TiO2@Ti3C2/g-C3N4 heterojunction hybrids would be desirable candidates for pollutants degradation.
关键词： 2D materials,photocatalytic activity,TiO2@Ti3C2/g-C3N4,ternary heterojunction,pollutants degradation,visible-light-driven
更新于2025-11-14 17:03:37
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Insights into the thermo-photo catalytic production of hydrogen from water on a low-cost NiOx-loaded TiO2 catalyst
摘要： Thermo-photo catalytic water splitting, where the introduction of thermal energy increases the oxidation driving force for narrow-band-gap photocatalysts (with a low valence band potential), exhibited significantly advanced performance for hydrogen production compared with general water splitting at room temperature. Herein, a low-cost NiOx-loaded TiO2 catalyst was reported for thermo-photo catalytic water splitting with methanol as the sacrificial agent. The catalyst with an optimal Ni ratio of 5 wt.% achieved a hydrogen evolution rate of 53.7 mmol/h/g under simulated AM 1.5G sunlight at 260℃, which was 2.5 times more than that without illumination, with apparent quantum efficiencies of 66.24%, 33.55%, 32.52% and 15.35% at 380, 420, 450 and 500 nm, respectively. More impressively, under the irradiation of visible light (λ>420 nm) at this temperature, and photohydrogen yield could still reach 26.9 mmol/h/g, which was 5 orders of magnitude greater than that (0.0011 mmol/h/g) conducted at room temperature. Isotope tracer experiments demonstrated that the introduction of photo energy promoted the hydrogen production mainly by enhancing hydrogen evolution from water splitting rather than methanol decomposition or reformation. Furthermore, the step-wise reaction mechanism was revealed with insights into the synergistic roles of thermo-energy and photo-energy for production of hydrogen from water. Those findings highlight the great promise of thermo-photo catalysis and should inspire more efforts for water splitting.
关键词： visible light,Hydrogen production,nickel-based catalysts,thermo-photo catalysis,titanium dioxide
更新于2025-11-14 17:03:37
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Visible light-induced oxidation of aqueous arsenite using facile Ag2O/TiO2 composites: Performance and mechanism
摘要： Conversion of aqueous arsenite [As(III)] to less toxic arsenate [As(V)] is a critical step for the arsenic pollution remediation. In this study, Ag2O/TiO2 composites synthesized via the pH-induced precipitation method were employed into the photocatalytic oxidation of As(III) under visible light irradiation. X-ray diffraction, transmission electron microscope and X-ray photoelectron spectroscopy analysis verified the formation of Ag2O/TiO2 heterostructures. Compared to pure Ag2O and TiO2, the 30% Ag2O/TiO2 composite exhibited much higher photochemical reactivities for the oxidation of As(III) under visible light irradiation. Under the optimal conditions [pH=4.0, the photocatalyst dosage being 0.3 g L-1 and initial As(III) concentration being 10 mg L-1], the oxidation and removal percent of As(III) was 60.7% and 83.0% after reaction for 120 min, respectively. Moreover, the formation of Ag(0) over the surface of Ag2O by photo-induced electrons contributed to the high stability of Ag2O/TiO2 composite. It was also found that photo-generated holes and superoxide radicals played the predominant roles in the As(III) oxidation. The improved photocatalytic activities were attributed to the formation of the hetero-junctions between Ag2O and TiO2, the strong visible light absorption, and the high separation efficiency of photo-generated electron-hole pairs resulted from the Schottky barriers at the Ag-Ag2O interface.
关键词： visible light,arsenite oxidation,Ag2O/TiO2 composite,photocatalytic
更新于2025-11-14 17:03:37
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Synthesis of visible light responsive iodine-doped mesoporous TiO2 by using biological renewable lignin as template for degradation of toxic organic pollutants
摘要： The visible light responsive I-doped mesoporous TiO2 (I/TiO2-T) catalysts were synthesized by facile hydrolysis method with lignin as a template. The resulting I/TiO2-T catalysts synthesized from different amounts of I as a dopant and lignin as a template were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-Vis diffuse spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL), and electrochemical impedance spectroscopy (EIS). The photocatalytic activities of the resulting catalysts were investigated by the degradation of p-chlorophenol under artificial visible light irradiation. The results showed that the lignin-templated TiO2 with a suitable amount of I-doping (I/TiO2-T) had higher catalytic activity than the catalyst prepared form I-doped TiO2 without lignin template (I/TiO2). Complete degradation of p-chlorophenol was achieved by I/TiO2-T with suitable amount of I-doping at 60 min. However, 95.7, 10.7, and 5.5% of the p-chlorophenol was degraded with I/TiO2, TiO2-T, and P25 catalysts, respectively, under 140 min visible light irradiation. The enhanced catalytic activities of the samples with template and I-doping may be due to the small grain size and high specific surface area of the catalysts. The band gap and the electrical properties of TiO2 also could be adjusted with I-doping. The I-doped TiO2 with the extrinsic I5+-to-Ti4+ and the iodine-to-oxygen donor defects could be excited by visible irradiation for efficient pollutants degradation. A possible photocatalytic mechanism for the degradation of the pollutants with I/TiO2-T under visible light irradiation was also proposed.
关键词： Mesoporous TiO2,Visible light,I-doped,Lignin template
更新于2025-11-14 17:03:37
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Stable Hybrid Perovskite MAPb(I1?Br )3 for Photocatalytic Hydrogen Evolution
摘要： Hybrid organic-inorganic perovskites have been pursuing for solar/visible-driven H2 evolution from hydrohalic acid (HX) splitting, but their inherent structural stability and performance are still challenging. Herein, we report on a stable hybrid perovskite MAPb(I1?xBrx)3 (x = 0 – 0.20) obtained by one-pot crystallization in a mixed halide parent solution and its implementation as a newcomer photocatalyst for H2 evolution in aqueous HX solution. MAPb(I1?xBrx)3 is demonstrated to be a superior visible-light-driven photocatalyst for H2 evolution in aqueous HI/HBr solution with no Pt as a cocatalyst. An optimized MAPb(I1?xBrx)3 (x = 0.10) shows a highest H2 evolution rate of 1471 μmol h?1 g?1 under visible light (λ ≥ 420 nm) illumination, which is ~ 40 times higher than that of pure MAPbI3, and the dual-halide perovskite is rather stable showing no obvious decrease in the photocatalytic activity over 60 runs (252 h). The perovskite inherent structural stability is further evidenced by XRD, UV-vis spectra and EDS elemental mapping of MAPb(I1?xBrx)3 measured after cycled photocatalytic reaction. The solar HI splitting efficiency of MAPb(I1?xBrx)3 (x = 0.10) is determined as 1.42%. The mechanism behind photocatalytic H2 evolution enhancement is elucidated by the experimental and computational methods.
关键词： photocatalyst,MAPb(I1?xBrx)3,hydrogen evolution,perovskite,visible light
更新于2025-11-14 15:28:36
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Photodegradation of thiophene over ZrO2–SiO2 nanoparticles: impact of copper decoration on their photocatalytic activity
摘要： A sol–gel technique was useful for the synthesis of zirconia–silica nanoparticles. Metallic copper has decorated zirconia–silica nanoparticles via photo-assisted deposition method, decorated copper mass percent was varied from 0.5, 1.0, 1.5, and 2.0 wt%. XRD results confirm that decoration of zirconia–silica nanoparticles by copper did not alert XRD pattern of zirconia–silica nanoparticles and there are no peaks for copper or copper oxide, due to high dispersion of copper above a surface of zirconia–silica nanoparticles. The decoration of zirconia–silica nanoparticles by copper was reduced band gap energy of zirconia–silica nanoparticles from 3.20 to 2.35 eV with 1.5 wt% Cu decoration. Photocatalytic oxidation of thiophene in presence of visible light was selected to measure the impact of metallic copper on photocatalytic activity of zirconia–silica nanoparticles. 1.5 wt% Cu-decorated zirconia–silica nanoparticles can degrade 100% of thiophene within 90 min.
关键词： ZrO2–SiO2,Sol–gel,Thiophene degradation,Cu decoration,Enhanced photocatalysis,Visible light
更新于2025-11-14 15:26:12
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Erbium-to-dysprosium energy-transfer mechanism and visible luminescence in lead-cadmium-fluorogermanate glass excited at 405?nm
摘要： Erbium-to-dysprosium energy-transfer and visible luminescence in the blue, green, yellow, red, and NIR is reported in PbGeO3:PbF2:CdF2 glass under 405 nm excitation. Absorption and excitation spectra were examined in the UV-VIS-IR spectral region. Emission showed a decrease in the Er3+ emissions around 520 and 545 nm when Dy3+ was added to the host matrix, while the Dy3+ emission around 576 nm (4F9/2 – 6H13/2) increased concomitantly. The recorded lifetime for Er3+ emissions also decreased, as Dy3+ concentration was increased for fixed Er3+ content. No similar behavior was observed when Er3+ concentration varied, confirming a one-way Er3+-to-Dy3+ energy transfer mechanism.
关键词： glass,energy-transfer,visible-light,rare-earth
更新于2025-11-14 15:25:21