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Highly Selective Photocatalytic Reduction of o-Dinitrobenzene to o-Phenylenediamine over Non-Metal-Doped TiO2 under Simulated Solar Light Irradiation
摘要： Photocatalytic reduction and hydrogenation reaction of o-dinitrobenzene in the presence of oxalic acid over anatase-brookite biphasic TiO2 and non-metal-doped anatase-brookite biphasic TiO2 photocatalysts under solar simulated light was investigated. Compared with commercial P25 TiO2, the prepared un-doped and doped anatase-brookite biphasic TiO2 exhibited a high selectivity towards the formation of o-nitroaniline (85.5%) and o-phenylenediamine ~97%, respectively. The doped anatase-brookite biphasic TiO2 has promoted photocatalytic reduction of the two-nitro groups of o-dinitrobenzene to the corresponding o-phenylenediamine with very high yield ~97%. Electron paramagnetic resonance analysis, Transient Absorption Spectroscopy (TAS) and Photoluminescence analysis (PL) were performed to determine the distribution of defects and the fluorescence lifetime of the charge carriers for un-doped and doped photocatalysts. The superiority of the doped TiO2 photocatalysts is accredited to the creation of new dopants (C, N, and S) as hole traps, the formation of long-lived Ti3+ defects which leads to an increase in the fluorescence lifetime of the formed charge carriers. The schematic diagram of the photocatalytic reduction of o-dinitrobenzene using the doped TiO2 under solar light was also illustrated in detail.
关键词： selectivity,photocatalysis,non-metal-doped TiO2,nitroaromatic compounds,reduction
更新于2025-09-23 15:22:29
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Photoelectrochemical Synthesis of Ammonia on the Aerophilic-Hydrophilic Heterostructure with 37.8% Efficiency
摘要： A unique aerophilic-hydrophilic heterostructure composed of Au nanoparticles highly dispersed in a poly(tetrafluoroethylene) porous framework is fabricated on a Si-based photocathode for N2-to-NH3 fixation. The amphipathic nature of the heterostructure is considered to be the origin of the enhanced nitrogen reduction reaction with efficient conversion efficiency and high production rate.
关键词： photoelectrochemical synthesis,ammonia,nitrogen reduction reaction,efficiency,aerophilic-hydrophilic heterostructure
更新于2025-09-23 15:22:29
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Pyranopterin Related Dithiolene Molybdenum Complexes as Homogeneous Catalysts for CO <sub/>2</sub> Photoreduction
摘要： Two original dithiolenes, with a pyrazine ring fused with a pyran ring carrying the dithiolene chelate, mimicking molybdopterin (MPT) present in the active site of formate dehydrogenases (FDHs), have been synthesized. The first one mimicks MPT in the dihydropyrazine form while the second mimicks MPT in the more biologically relevant tetrahydropyrazine form. Both have been structurally characterized as a ligand within a cobalt(cyclopentadienyl)(dithiolene) complex. The corresponding MoO(dithiolene)2 complexes have been also prepared and are reported as the first functional and stable catalysts inspired by the Mo center of FDHs so far: they indeed catalyze the photoreduction of CO2 into formic acid, as the major product, and carbon monoxide, achieving more than 100 turnover numbers in about 8 h.
关键词： CO2 reduction,homogeneous catalysis,molybdenum complex,dithiolene ligands
更新于2025-09-23 15:22:29
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Three-in-one oxygen vacancy: whole visible-spectrum absorption, efficient charge separation and surface site activation for robust CO2 photoreduction
摘要： Exploitation of efficient catalysts to realize solar-driven conversion of inert CO2 into useful fuels confronts big challenges owing to the poor photoabsorption, sluggish charge separation and inefficient surface reactive sites of photocatalysts. Herein, we report a facile and controllable in situ reduction strategy to create surface oxygen vacancies (OVs) on Aurivillius-phase Sr2Bi2Nb2TiO12 nanosheets. Sr2Bi2Nb2TiO12 nanosheets are for the first time prepared by a mineralizer-assisted soft-chemical method, and the introduction of OVs on the surface of Sr2Bi2Nb2TiO12 not only extends photo-response region, but also tremendously promotes separation of photo-induced charge carriers. Moreover, the adsorption and activation of CO2 molecules on the surface of the catalyst are largely enhanced. In the gas-solid reaction system without any co-catalysts or sacrificial agents, OVs-abundant Sr2Bi2Nb2TiO12 nanosheets show an outstanding CO2 photoreduction activity in producing CO with a rate of 17.11 μmol g?1 h?1, ~58 times higher than that of the bulk counterpart, surpassing most previously reported state-of-the-art photocatalysts. Our study provides a three-in-one integrated solution to advance the comprehensive performance of photocatalysts for solar-energy conversion and generation of renewable energy.
关键词： Sr2Bi2Nb2TiO12 nanosheets,oxygen vacancies,charge separation,photocatalytic CO2 reduction
更新于2025-09-23 15:22:29
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Pulsed laser deposition of BaCo0.4Fe0.4Zr0.1Y0.1O3-δ cathode for solid oxide fuel cells
摘要： We herein report a thin film deposition of perovskite BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) by pulsed laser depositing (PLD) method for the use as a cathode in solid oxide fuel cells (SOFCs). The BCFZY powder was first synthesized via sol-gel method and pelletized to use it as a target in PLD system. As a result, the PLD-deposited thin film showed nano-porous morphology, preferred nano-architecture for cathode in SOFCs, without generating or transforming to secondary phase. The applicability of the thin film BCFZY to SOFC cathode was even confirmed by fabricating an SOFC with BCFZY cathode and operating it at 500 °C, where stable open-circuit voltage of 1.13 V was measured for an hour.
关键词： Pulsed laser deposition,Oxygen reduction reaction,thin film,Solid oxide fuel cells,BCFZY
更新于2025-09-23 15:22:29
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Biomimetic Polyimide-Supported Cuprous Oxide Photocatalytic Film with Tunable Hydrophobicity, Improved Thermal Stability, and Photocatalytic Activity toward CO <sub/>2</sub> Reduction
摘要： Flexible and thermally stable polyimide (PI) ?lms containing a hierarchical surface structure were synthesized as substrates to support visible-light active cuprous oxide for photocatalytic reduction of carbon dioxide for the ?rst time. With the nanocasting technique, the surface structure on the leaves of Xanthosoma sagittifolium was successfully duplicated on PI ?lms. Followed by the ion-exchange process and adequate thermal treatment, cuprous oxide nanoparticles were successfully immobilized on the arti?cial PI leaves and exhibited the capability to photoreduce carbon dioxide into carbon monoxide under visible-light illumination. With the selection of biomimetic structures and adjustment of fabrication parameters, the hydrophobicity and optical absorption edge of the photocatalytic ?lm were tunable. An increase in hydrophobicity improved the yield of carbon monoxide. The introduction of a hierarchical structure on the surface and cuprous oxide within the matrix dramatically enhanced the thermal stability of the PI ?lm. The ?exible photocatalytic ?lm is a promising material for the applications requiring high mechanical and thermal stability, such as industrial ?ue-gas treatments.
关键词： Thermal Stability,CO2 Reduction,Hydrophobicity,Polyimide,Photocatalytic,Biomimetic,Cuprous Oxide
更新于2025-09-23 15:22:29
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Facile Preparation of Unsubstituted Iron(II) Phthalocyanine/Carbon Nitride Nanocomposites: A Multipurpose Catalyst with Reciprocally Enhanced Photo/Electrocatalytic Activity
摘要： The development of new catalytic materials is conducive to solving the global energy crisis and environmental problems. In this work, multipurpose catalyst unsubstituted iron(II) phthalocyanine/carbon nitride nanosheet (FePc/CN) nanocomposites were prepared by utilizing concentrated sulfuric acid as an ideal solvent of CN and unsubstituted FePc. Such FePc/CN nanocomposites exhibited improved photo/electrocatalytic activity which was enhanced reciprocally: the photocatalytic activity of CN was promoted by FePc anchoring, and the electrocatalytic activity of FePc was improved by CN doping. The photocatalytic performance of FePc/CN?0.3 nanocomposites was about 6.4 and 1.7 times as high as FePc and CN, which was attributed to two reasons: (1) the anchoring FePc on CN extended the visible-light absorption region of CN, (2) the electron transfer from excited FePc to CN hindered charge carriers recombination and thus enhanced the photoinduced carrier separation efficiency. Relative to FePc and CN, the onset potential of FePc/CN?0.3 was positively shifted by 52 and 174 mV, such higher oxygen reduction reaction activity was due to the uniform dispersion of FePc on the supporting material CN without aggregation, which led to improved conductivity and stability of nanocomposites. This approach will contribute to an inexpensive and convenient synthetic strategy of transition-metal-based nanostructures for functional applications in photovoltaic, electrochemical, and catalytic fields.
关键词： Unsubstituted iron(II) phthalocyanine,Oxygen reduction reaction,Multipurpose catalyst,Photocatalytic performance,Carbon nitride nanosheet
更新于2025-09-23 15:22:29
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[IEEE 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - Bangkok, Thailand (2018.9.26-2018.9.29)] 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - Optimal Grid-Connected with Multi-Solar PV Placement and Sizing for Power Loss Reduction and Voltage Profile Improvement
摘要： The 18th International Symposium on Communications and Information Technologies (ISCIT 2018) paper discusses the use of solar PV (photovoltaic) cells in a distribution system for power loss reduction and voltage profile improvement. It presents an analytical approach to determine the optimal placement and sizing of solar PV units in a distribution system to minimize power losses and enhance voltage stability. The study involves simulations and case studies to validate the proposed method.
关键词： voltage profile,distribution system,solar PV,optimal placement,sizing,power loss reduction
更新于2025-09-23 15:22:29
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An interprojection sensor fusion approach to estimate blocked projection signal in synchronized moving grid-based CBCT system
摘要： Purpose: A preobject grid can reduce and correct scatter in cone beam computed tomography (CBCT). However, half of the signal in each projection is blocked by the grid. A synchronized moving grid (SMOG) has been proposed to acquire two complimentary projections at each gantry position and merge them into one complete projection. That approach, however, suffers from increased scanning time and the technical difficulty of accurately merging the two projections per gantry angle. Herein, the authors present a new SMOG approach which acquires a single projection per gantry angle, with complimentary grid patterns for any two adjacent projections, and use an interprojection sensor fusion (IPSF) technique to estimate the blocked signal in each projection. The method may have the additional benefit of reduced imaging dose due to the grid blocking half of the incident radiation. Methods: The IPSF considers multiple paired observations from two adjacent gantry angles as approximations of the blocked signal and uses a weighted least square regression of these observations to finally determine the blocked signal. The method was first tested with a simulated SMOG on a head phantom. The signal to noise ratio (SNR), which represents the difference of the recovered CBCT image to the original image without the SMOG, was used to evaluate the ability of the IPSF in recovering the missing signal. The IPSF approach was then tested using a Catphan phantom on a prototype SMOG assembly installed in a bench top CBCT system. Results: In the simulated SMOG experiment, the SNRs were increased from 15.1 and 12.7 dB to 35.6 and 28.9 dB comparing with a conventional interpolation method (inpainting method) for a projection and the reconstructed 3D image, respectively, suggesting that IPSF successfully recovered most of blocked signal. In the prototype SMOG experiment, the authors have successfully reconstructed a CBCT image using the IPSF-SMOG approach. The detailed geometric features in the Catphan phantom were mostly recovered according to visual evaluation. The scatter related artifacts, such as cupping artifacts, were almost completely removed. Conclusions: The IPSF-SMOG is promising in reducing scatter artifacts and improving image quality while reducing radiation dose.
关键词： moving grids,scatter correction,interpolation,sensor fusion,geometric model,SMOG,dose reduction,CBCT
更新于2025-09-23 15:22:29
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An Investigation into the Stability of Graphitic C <sub/>3</sub> N <sub/>4</sub> as a Photocatalyst for CO <sub/>2</sub> Reduction
摘要： The increasing CO2 concentration in the atmosphere exerts a significant influence on global warming and climate change. The capture and utilization of CO2 by conversion to useful products is an area of active research. In this work, the photo-driven reduction of CO2 was investigated using graphitic carbon nitride (g-C3N4) as a potential photocatalyst. The photocatalytic reduction of CO2 was investigated with g-C3N4 powder immobilized on a glass support in a batch gas phase photoreactor. The experiments were carried out under UV-Vis irradiation at 70°C and an initial pressure of 2.5 bar. The only gas phase product detected during the irradiation of the g-C3N4 in the presence of CO2 was CO, and the rate of production was observed to decrease over time. Oxygen doped g-C3N4 was also tested for CO2 reduction but had lower efficiency that the parent g-C3N4. Repeated cycles of photocatalytic CO2 reduction showed a decline in the activity of the g-C3N4. In the absence of CO2 some CO generation was also observed. Characterization of used and unused materials, using FTIR and XPS, showed an increase in the oxygen functional groups following UV-Vis irradiation or thermal treatment. While others report the use of g-C3N4 as a photocatalyst, this work highlights the important need for replicates and control testing to determine material stability.
关键词： CO2 reduction,photocatalysis,oxygen doping,graphitic carbon nitride,material stability,g-C3N4
更新于2025-09-23 15:21:21