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Efficient and stable photocatalytic reduction of aqueous hexavalent chromium ions by polyaniline surface-hybridized ZnO nanosheets
摘要： ZnO/PNAI nanocomposites were obtained via a simple two-step method, in which a hierarchically ?ower-like ZnO, assembled from nanosheets, was ?rst synthesized by low temperature (80 °C) solution method without surfactant/template and then, an in-situ polymerization of aniline onto the ZnO nanosheets was carried out. The characterization was actualized on the synthesized nanocomposite using XRD, Raman, TG-DSC, UV–vis-DRS, PL, XPS, SEM, TEM and N2 adsorption-desorption analysis. An ef?cient and stable photocatalytic activity was exhibited by the synergistic ZnO/PNAI nanocomposites on the reduction of toxic Cr(VI) to benign Cr(III) in comparison with the pristine ZnO and other semiconductor/PANI materials reported. The in?uence of parameters such as solution pH, initial Cr(VI) concentration and the addition of organic sacri?ces on the Cr(VI) removal ef?ciency was investigated. It was found that the Cr(VI) removal was strongly pH-dependent and the optimum pH range was 4–7 for ZnO/PANI composite catalyst. The Langmuir–Hinshelwood kinetic examination showed that the surface photoreaction was the rate-determining step to compare the adsorption equilibrium. The organic additives such as EDTA and citric acid can promote the photocatalytic ef?ciency and the solution of EDTA/HCl can well restore the photoreduction ability of ZnO/PANI catalyst. Moreover, the reusability of photocatalyst was also tested to estimate the practicability.
关键词： ZnO/PANI nanocomposites,Photocatalytic reduction,Hexavalent chromium,Synergistic effect
更新于2025-09-19 17:15:36
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Enhanced UV-Vis-NIR activated photocatalytic activity from Fe <sup>3+</sup> -doped BiOBr:Yb <sup>3+</sup> /Er <sup>3+</sup> upconversion nanoplates: synergistic effect and mechanism insight
摘要： Upconversion (UC) materials are recognized as promising candidates to harvest solar energy for photocatalysis. In this work, a simple strategy for simultaneously enhancing the UC luminescence and photocatalytic efficiency of BiOBr:Yb3+/Er3+ nanoplates through Fe3+ ion doping is reported. Compared to the Fe3+-free sample, the UC emission intensity was significantly enhanced through tailoring of the crystal symmetry by Fe3+ ions. Experiment and DFT calculations reveal that the introduction of Fe3+ ions resulted in the formation of an impurity energy level, extending to the light absorption region. As expected, the Fe3+-doped BiOBr:Yb3+/Er3+ nanoplates exhibit a wide photoresponse from the UV to NIR regions, good stability, and obviously enhanced photocatalytic activities compared with the BiOBr:Yb3+/Er3+ nanoplates in the degradation of RhB. The boosted photocatalytic activity can be attributed to the synergic effect of the efficient utilization of UC luminescence and Fe3+ doping, where Fe3+ doping could improve the light harvesting capacity, enhance the separation efficiency of electron and hole (e?/h+) pairs, and promote the production of highly oxidative species. This work not only provides a promising system for the efficient utilization of solar light, but also offers a feasible guideline for the further design of broad-spectrum active photocatalysts.
关键词： Enhanced UV-Vis-NIR activated photocatalytic activity,mechanism insight,Fe3+-doped BiOBr:Yb3+/Er3+ upconversion nanoplates,synergistic effect
更新于2025-09-19 17:15:36
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Synergistic effect of additives on 2D perovskite film towards efficient and stable solar cell
摘要： Recently，two-dimensional (2D) organic-inorganic hybrid perovskites have attracted tremendous attention due to their excellent environment stability. However, the inhibition of out-of-plane charge transport limits the performance of 2D based perovskite solar cells (PVSCs). To overcome this issue, we prepare the vertical-orientated 2D perovskite film via introducing dimethyl sulfoxide (DMSO) and thio-semicarbazide (TSC) as additives into the precursor solution. High-quality 2D (BA)2(MA)3Pb4I13 (BA = n-butylammonium, MA = methylammonium) films with uniform morphology, increased grain size, intensified crystallinity and vertical orientation are therefore fabricated by a synergistic effect of additives. As a result, the trap-state density in 2D (BA)2(MA)3Pb4I13 films is reduced and the charge transport is remarkably improved. The power conversion efficiency (PCE) of the PVSCs is boosted from the 1.05% to 14.15%. An unsealed device retains 90.3% of its initial PCE after 720 h storage in air atmosphere with relative humidity of 25 ± 5% at 25 °C. The results show the synergistic effect of TSC and DMSO on perovskite films is an effective approach toward efficient and stable 2D PVSC.
关键词： stability,charge transport,orientation,synergistic effect,crystallization process,2D perovskite
更新于2025-09-19 17:13:59
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High-performance solar vapor generation of Ni/carbon nanomaterials by controlled carbonization of waste polypropylene; ??ˉ??§?￠3????o????è???????ˉ????¤?é??/?￠3?o3?±3????????¨?o?é????????è???°?è????￠;
摘要： Solar vapor generation is emerging as a promising technology using solar energy for various applications including desalination and freshwater production. However, from the viewpoints of industrial and academic research, it remains challenging to prepare low-cost and high-efficiency photothermal materials. In this work, we report the controlled carbonization of polypropylene (PP) using NiO and poly(ionic liquid) (PIL) as combined catalysts to prepare a Ni/carbon nanomaterial (Ni/CNM). The morphology and textural property of Ni/CNM are modulated by adding a trace amount of PIL. Ni/CNM consists of cup-stacked carbon nanotubes (CS-CNTs) and pear-shaped metallic Ni nanoparticles. Due to the synergistic effect of Ni and CS-CNTs in solar absorption, Ni/CNM possesses an excellent property of photothermal conversion. Meanwhile, Ni/CNM with a high specific surface area and rich micro-/meso-/macropores constructs a three-dimensional (3D) porous network for efficient water supply and vapor channels. Thanks to high solar absorption, fast water transport, and low thermal conductivity, Ni/CNM exhibits a high water evaporation rate of 1.67 kg m?2 h?1, a solar-to-vapor conversion efficiency of 94.9%, and an excellent stability for 10 cycles. It also works well when converting dye-containing water, seawater, and oil/water emulsion into healthy drinkable water. The metallic ion removal efficiency of seawater is 99.99%, and the dye removal efficiency is >99.9%. More importantly, it prevails over the-state-of-art carbon-based photothermal materials in solar energy-driven vapor generation. This work not only proposes a new sustainable approach to convert waste polymers into advanced metal/carbon hybrids, but also contributes to the fields of solar energy utilization and seawater desalination.
关键词： synergistic effect,waste polymer,solar vapor generation,Ni/carbon nanomaterial,controlled carbonization,photothermal materials
更新于2025-09-19 17:13:59
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Research on Carrier Recovery Algorithm in Coherent Optical Communication System
摘要： The generation of tar in biomass gasification is highly undesirable since the condensation and agglomeration of tar causes clogging and contamination of downstream equipment, leading to low energy efficiency and high maintenance cost. Currently, the most widely used methods for tar reforming are catalytic reforming and plasma reforming. However, the main drawbacks for these two processes are: (i) the rapid catalyst deactivation caused by poisoning, sintering and coke deposition for catalytic reforming, and (ii) low energy efficiency, low selectivity of syngas and the formation of undesirable byproducts for plasma reforming. Recently, therefore, the hybrid plasma-catalysis system has attracted much attention for tar reforming, since it can overcome the above-mentioned drawbacks and generate a synergy effect. The addition of catalyst in plasma could change the discharge properties of plasma, and the plasma could also modify the catalyst property and change the status of reactants. At present, very few review articles have reported and compared the performances of tar reforming in the plasma-only, catalysis-only and hybrid plasma-catalysis system. Therefore, this review paper focus on: (i) the deactivation characteristics and modification methods of steam-reforming catalysts, as well as the mechanism of tar catalytic reforming; (ii) the performance of tar reforming in various plasma reactors and the reaction mechanism based on the analysis of byproducts and energetic plasma species; and (iii) the possible synergistic effect of plasma and heterogeneous catalyst in a hybrid plasma-catalysis system caused by the multiple interactions of plasma and catalysts.
关键词： Catalytic reforming,Biomass gasification,Synergistic effect,Plasma reforming,Tar
更新于2025-09-19 17:13:59
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In situ electrodeposition of nickel cobalt selenides?on FTO as an efficient counter electrode for dye-sensitized solar cells
摘要： Construction of transition metal selenides with high electrocatalytic performance is of significant importance, but it is still a challenge to develop the corresponding counter electrodes (CEs) by an electrodeposition technique. In the present work, nickel cobalt selenide (NixCoySe) films are prepared in situ on fluorine-doped tin oxide (FTO) glasses through a potential reversal electrodeposition technique. The morphology and electronic structure of NixCoySe films can be tuned by controlling the Ni/Co molar ratio in electroplating solution. Specially, NixCoySe-6 film (the Ni/Co molar ratio of 1:1) with the optimized interaction between the Ni and Co elements displays numerous particles composed of sheets attached with nanocrystals, resulting in the more electrocatalytic active sites. Benefiting from the unique morphology and optimized synergistic effect, NixCoySe-6 CE exhibits superior electrocatalytic activity for the triiodide reduction. Then, the dye-sensitized solar cell (DSC) fabricated by NixCoySe-6 CE has demonstrated a power conversion efficiency (PCE) over 7.40%, which is higher than that of platinum (Pt)-based device (6.32%). Furthermore, NixCoySe-6 array CE is also prepared by using polystyrene array as template. The PCE of the DSC with NixCoySe-6 array CE reaches its maximum value of 7.64% and 20.9% larger than that of Pt-based device.
关键词： Potential reversal electrodeposition technique,Synergistic effect,Nickel cobalt selenides,Counter electrodes,Array
更新于2025-09-16 10:30:52
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Hierarchically assembled porous TiO2 nanoparticles with enhanced photocatalytic activity towards Rhodamine-B degradation
摘要： Despite tremendous advances in the development of photocatalysts for waste water treatment, the harmful chemicals used in the synthesis reaching the water bodies add up new environmental issues. In this work, hierarchically assembled porous TiO2 nanoparticles (TiO2 NPs) were prepared by an acid-free eco-friendly hydrothermal approach via condensation of alkoxide precursor (titanium (IV) tert-butoxide). Fine tuning of textural properties was facilitated by change in the hydrothermal treatment time. The structure, morphology and the physicochemical properties of the synthesized samples were characterized by XRD, TGA, N2 adsorption-desorption, FE-SEM, and FE-TEM analysis. N2 adsorption-desorption displays a unique double-slit model isotherms for all the samples. The BJH mesopore distribution curves exhibit intense peak at 6.9 nm and slightly broad peak at 46.1 nm in all the samples with further broad peaks in the range of 80-95 nm. The results showed that the photocatalytic activity is highly depend on the textural properties especially pore diameter. The activity and pore diameter were found to follow the trend: TiO2-12h > TiO2-48h > TiO2-24h > TiO2-6h whereas the surface area and crystallite size follows the trend: TiO2-48h > TiO2-12h > TiO2-24h > TiO2-6h. Overall, a simple strategy is presented and could be extended to produce various metal oxides for photocatalytic degradation of various other pollutants and microorganisms.
关键词： Synergistic effect,Rhodamine B degradation,Hierarchical pore structure,TiO2 nanoparticles
更新于2025-09-12 10:27:22
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Synergistic Effect of Metal-Organic Framework/Gallic Acid in Enhanced Laser Desorption/Ionization Mass Spectrometry
摘要： Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has become an indispensable tool for high throughput analysis of macromolecules, but many challenges still remain in detection of small molecules due to the severe matrix-related background interference in the low-molecular mass ranges (MW < 700 Da). Herein, a gallic acid (GA)-functionalized zirconium1,4-dicarboxybenzene metal-organic framework (MOF) (denoted as UiO-66-GA) was designed to serve as a new substrate and a novel strategy on the basis of the synergistic effect of MOF and GA was developed to enhance LDI process. In comparasion with conventional organic matrices, the UiO-66-GA substrate showed superior LDI performance in the analysis of a wide varity of molecules including amino acids, unsaturated fatty acids, bisphenols (BPs), oligosaccharides, peptides, protein, and polyethylene glycol (PEG) of various average molecular weights from 200 to 10000. Perfluorooctanoic sulfonate (PFOS) was used to evaluate the ability of quantitative analysis and its corresponding limit of detection (LOD) as low as 1 fmol was achieved. High sensitivity and good salt tolerance of the UiO-66-GA-assisted LDI-MS were allowed to determine ultratrace PFOS in the spiked human urine and serum samples. In addition, the synergistic mechanism of MOF and GA in enhanced LDI process was investigated by comprehensively comparing GA- and its analogues functionalized UiO-66, and the results revealed that two aspects contributed to the enhanced LDI process: 1) an enhancement in metal-phenolic coordination system of UiO-66-GA promoted laser absorption and energy transfer; 2) introduction of carboxyl- and hydroxyl groups of GA onto UiO-66 facilitated the LDI process in both positive- and negative ion modes. This work expands a new domain for the MOF applications and provides a promising alternative for various molecule analysis.
关键词： LDI-MS,macromolecules,Synergistic effect,UiO-66-GA,small molecules
更新于2025-09-11 14:15:04
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Ag-Ag2S quantum-dots modified TiO2 nanorod arrays with enhanced photoelectrochemical and photocatalytic properties
摘要： In this paper, highly ordered titanium dioxide nanorod (TNR) arrays decorated with Ag-Ag2S quantum-dots (QDs) were synthesized on FTO substrate through hydrothermal treatment and in-situ vulcanization. The content of Ag2S QDs on Ag/TNR was controlled by changing the immersion time of Ag/TNR in the N-N-dimethyl formamide (DMF) solution containing dissolved sulfur element. The morphology, structure, composition and optical, photoelectric and photocatalytic properties of QDs/TNR arrays were studied in detail. In the visible range, the QDs/TNR array with a soaking time of 12 h exhibits the maximal photocurrent density (0.082 mA/cm2) and photodegradation rate (62.2%), which is 5.5 and 1.85 times higher than that of pure TNR. The improvement of these properties could be attributed to synergy effect between Ag and Ag2S materials. That is, Ag QDs can stably capture and transmit photo-generated electrons from the TNR surface, whereas the Ag2S promoter is regarded as the interface active sites to enhance photocatalytic reactions. Therefore, the synergistic effect of Ag-Ag2S can significantly enhance the photoelectrochemical and photocatalytic propertise of the TNR arrays.
关键词： Ag-Ag2S quantum-dots,photoelectrochemical and photocatalytic properties,synergistic effect,TiO2 nanorod arrays
更新于2025-09-10 09:29:36
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Photo-thermal Synergistically Catalytic Conversion of Glycerol and Carbon Dioxide to Glycerol Carbonate over Au/ZnWO4-ZnO Catalysts
摘要： Converting glycerol and CO2 into glycerol carbonate offers a green pathway for utilizing biodiesel by-product glycerol and greenhouse gas CO2 as well as synthesizing the important chemical compound glycerol carbonate. In this study, for the first time, the abundant visible light was introduced into thermal-driven glycerol carbonylation system, aiming to improve catalyst performance via breaking the thermodynamic equilibrium limitations. Here x%Au/ZnWO4-ZnO catalysts were designed for the photo-thermal catalytic system. It was found that, ZnWO4-ZnO itself was effective in glycerol carbonylation even under thermal-driven condition, and the loading of plasmonic Au further enhanced the catalytic performances especially with visible light irradiation. The visible light responsivity of the catalysts and reaction temperatures played important roles for the photo-thermal performance of x%Au/ZnWO4-ZnO, indicating the strong photo-thermal synergistic effect for the highly promoted catalytic performance. This study suggests the photo-thermal synergistic catalysis is one of efficient approaches for further improving catalytic performance.
关键词： photo-thermal,glycerol carbonylation,localized surface plasmon resonance,synergistic effect,glycerol carbonate synthesis
更新于2025-09-09 09:28:46