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Low-cost effective photocatalytic activity under visible light of pitch-based porous carbon nanofiber composites aided by zinc oxide
摘要： To explore and develop an economical, novel, and effective photocatalyst for the degradation of methylene blue (MB) under visible-light irradiation, polyacrylonitrile (PAN)/pitch-based carbon nanofibers (CNFs) with ZnO (PPZn) are successfully produced by one-step electrospinning of PAN, pitch, and zinc acetate in dimethylformamide (DMF) solution. The charge separation rate, adsorption capacity, and visible-light harvesting effects are all enhanced by the synergistic effect of PAN/pitch-based CNFs and ZnO coupling. The resulting PPZn photocatalysts exhibit excellent removal capacity of 100% of MB within 30 min and a kinetic rate constant of 0.018 min?1 under visible light. PPZn also exhibits a consistent and stable photocatalytic performance by maintaining nearly 100% removal of 15 ppm MB over 8 regeneration cycles. The PP-based CNFs in PPZn act as a charge reservoir to afford fast transport for suppressing the e?–h? recombination and high electrical conductivity induced by the pitch, thereby expanding the visible-light response. The PP(3)Zn composites demonstrate a promising potential as a low-cost photocatalyst material offering excellent photocatalytic efficiency in the visible-light spectrum.
关键词： Carbon nanofiber,ZnO,Methylene blue,Pitch,Visible light,Photocatalytic activity
更新于2025-09-23 15:23:52
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Improving the Visible-Light Photocatalytic Activity of Graphitic Carbon Nitride by Carbon Black Doping
摘要： Hydrogen production by water splitting and the removal of aqueous dyes by using a catalyst and solar energy are an ideal future energy source and useful for environmental protection. Graphitic carbon nitride can be used as the photocatalyst with visible light irradiation. However, it typically suffers from the high recombination of carriers and low electrical conductivity. Here, we have developed a facile mix-thermal strategy to prepare carbon black-modified graphitic carbon nitrides, which possess high electrical conductivity, a wide adsorption range of visible light, and a low recombination rate of carriers. With the help of carbon black, highly crystallized graphitic carbon nitrides with built-in triazine and heptazine heterojunctions are obtained. Improved photocatalytic activities have been achieved in carbon black-modified graphitic carbon nitride. The dye removal rate can be three times faster than that of pristine graphitic carbon nitride and the photocatalytic H2 generation is 234 μmol h?1 g?1 under visible light irradiation.
关键词： aqueous dyes removal,hydrogen production,carbon black doping,graphitic carbon nitride,visible-light photocatalytic activity
更新于2025-09-23 15:21:21
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In situ fluorine doped ZrO2?x nanotubes for efficient visible light photocatalytic activity
摘要： The F-doped ZrO2?x nanotubes are synthesized by anodic oxidization in a F-containing electrolyte and following a low temperature annealing process. The F-doped ZrO2?x nanotubes exhibit a dramatic increase in visible light absorption and efficient visible light photocatalytic activity which are not possessed to normalized ZrO2. The fluorine in anodic ZrO2 nanotubes plays a vital role in the formation of abundant anion vacancies during the annealing. Combining the doping effect of the residual fluorine element, the band gap of the F-doped ZrO2?x nanotubes reduced from 5.13 to 2.35 eV. Moreover, the transient photocurrent response plots and the photocatalytic experiments reveal the highly effective electrons–holes separation of the F-doped ZrO2?x nanotubes and enhanced visible-light photocatalytic degradation for RhB. The degradation rate of RhB in the presence of the F-doped ZrO2?x nanotubes catalyst has reached up to 83% under 2 h low-power LED light irradiation. In addition, the possible photocatalytic mechanism of the F-doped ZrO2?x nanotubes has been proposed via studying the band structure. It is believed that the F-doped ZrO2?x nanotubes will have a bright future for sustainable energy sources and cleaning environment.
关键词： oxygen vacancies,F-doped ZrO2?x nanotubes,anodic oxidization,visible light photocatalytic activity,band gap narrowing
更新于2025-09-23 15:21:01
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Functionalization of cotton fabric with bismuth oxyiodide nanosheets: applications for photodegrading organic pollutants, UV shielding and self-cleaning
摘要： A multifunctional cotton fabric was prepared by immobilizing bismuth oxyiodide (BiOI) nanosheets on the surface of cotton treated to briefly dissolve surface molecules with upon the low-temperature addition of NaOH and urea (cotton micro-dissolution). Immobilization was accomplished by successive adsorption and reaction (SILAR) at the temperature (* 25 °C). The morphology, structural characteristics, photodegradation ability for organic pollutants, UV shielding, and self-cleaning of the treated fabric were studied. The growth rate and uniformity of the BiOI nanosheets were compared between the treated fabrics and the untreated fabrics. The absorption wavelength of the cotton fabric with BiOI nanosheets was extended to the visible light (* 630 nm) region. Under visible light irradiation, cotton fabric containing BiOI nanosheets (BiOI > 8.4 wt%) showed remarkable photocatalytic ability for degrading rhodamine B (RhB) with a degradation rate of 99% (C0 = 20 mg/L) and 95% after the first and sixth cycle, respectively. The ultraviolet protection factor (UPF) of cotton fabric with BiOI nanosheets was > 50, and its transmittance of ultraviolet A (T(UVA)) was < 5%. The cotton fabric with BiOI nanosheets also exhibited superhydrophobic and self-cleaning properties. Thus, the cotton fabric with BiOI nanosheets has great potential for application as a multifunctional protective material.
关键词： BiOI nanosheets,Visible-light photocatalytic activity,Superhydrophobicity,Ultraviolet protection factor
更新于2025-09-19 17:15:36
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Facile synthesis of molybdenum multisulfide composite nanorod arrays from single-source precursor for photoelectrochemical hydrogen generation
摘要： The deposition of molybdenum multisulfide thin-film photoanodes from the metal–organic precursor [CpMo(SMe)2]2 (1), at different deposition time has been investigated. Four different films were deposited at 550 °C under constant argon gas flow for 10, 15, 20, and 25 min, respectively. The surface morphology of these films analyzed with FE-SEM and AFM showed the presence of compact 1D rod-like structure of MoS2/Mo2S3 in a homogeneous form. The average diameter of the 1D compact MoS2/Mo2S3 composite nanorod arrays was found in the range of 155–298 nm deposited for different time durations. EDX analysis showed a consistency where the Mo-to-S ratio was approximately 3:4.5 and demonstrated the overall composition of the 1D MoS2/Mo2S3 composite nanorod arrays. The XRD analysis of the thin film indicated the presence of monoclinic Mo2S3 and rhombohedral MoS2 composite system. Moreover, the photocurrent density of 20 min deposited thin film is observed to be 4 mA/cm2 with highest photosensitivity of 6.78 at the overpotential of 0.3 V vs Ag/AgCl under the simulated light intensity of 100 mW/cm2 (AM 1.5G). The electrochemical impedance spectroscopy (EIS) also showed improved charge transportation with highest lifetime of the photoexcited charges in 20 min deposited thin film in comparison to the other deposition time durations. This study provides the optimized synthesis conditions for producing molybdenum-based multisulfide nanostructures and the deposition duration for their deployment in solar-based devices.
关键词： Visible light photocatalytic activity,Single-source precursor,Thin films,MoS2/Mo2S3 composite
更新于2025-09-19 17:15:36
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Lignite-derived carbon quantum dot/TiO <sub/>2</sub> heterostructure nanocomposites: photoinduced charge transfer properties and enhanced visible light photocatalytic activity
摘要： Here, we present a facile and green route to cleanly and efficiently utilize low-rank lignite to produce in high yields and in situ synthesize CQDs/TiO2 heterostructure nanocomposites. Unlike other CQDs, the lignite-derived CQDs exhibit obvious concentration-dependent red-shifted absorption, unusual aggregation-induced different color emissions and strong orange-red solid-state fluorescence. Through the optimization of the CQD loading proportion, the 2 wt% CQDs/TiO2 shows the optimal photocatalytic performance under visible light. We highlight the CQDs/TiO2 heterostructure nanocomposites by focusing on their dynamic photoinduced charge transfer properties triggered by the heterostructure interface and their application as a photocatalyst under visible light. Our detailed work about the transfer behavior of photoinduced charges in coal-derived carbon quantum dot/TiO2 heterostructure nanocomposites may shed light on the intrinsic reasons for CQD/semiconductor enhanced photocatalytic activity.
关键词： photoinduced charge transfer,heterostructure nanocomposites,visible light photocatalytic activity,lignite-derived carbon quantum dots,TiO2
更新于2025-09-16 10:30:52
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A synthesis of graphene quantum dots/hollow TiO2 nanosphere composites for enhancing visible light photocatalytic activity
摘要： Given the versatility and value of the semiconductor composites for photocatalysis, we reported a new, friendly environment, high specific surface area material of the graphene quantum dots/hollow titanium dioxide nanosphere (GQDs/H-TiO2) composites which are synthesized through a simple hydrothermal method. GQDs (~ 5 nm) exhibit highly photoluminescent and widely visible light absorption properties. H-TiO2 has high surface area and abundant exposed active sites for photocatalysis. The research demonstrates that GQDs coupled on H-TiO2 can effectively enlarge the light absorption of the H-TiO2 to visible region (~ 650 nm) and enhance the electron–hole pair separation efficiency of GQDs/H-TiO2 composites owing to GQDs acting as an electron repository and electron transport bridge. In our delight, the photocurrent enhancement of newly prepared GQDs-3.0/H-TiO2 composite electrode was almost 3.5 times higher in comparison with that in pure H-TiO2 electrode at an applied voltage of 0.5 V using Na2SO4 (0.5 M) solution as the electrolyte. In addition, the photocatalytic activity of the prepared GQDs-3.0/H-TiO2 (96.9%) on the degradation of Rhodamine B (RhB) was also significantly enhanced compared with that of pure H-TiO2 (33.3%) after 180 min. The protocol is suitable not only for the GQDs-modified semiconductors photocatalysts but also provides further insights to apply GQDs to other energy conversion devices.
关键词： composites,graphene quantum dots,hollow TiO2 nanosphere,visible light photocatalytic activity
更新于2025-09-12 10:27:22
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Enhanced visible light photocatalytic activity of zno nanoparticles modified by cyclized polyacrynitrile
摘要： The ZnO/cyclized polyacrylonitrile (CPAN) composites were prepared by impregnation and heat treatment process. The morphology, crystal internal structure of ZnO/CPAN nanocomposites were characterized by UV-vis-diffuse reflectance spectroscope (DRS), X-ray diffraction, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The visible light photocatalytic activity of ZnO/CPAN was evaluated by degradation of methyl orange under xenon lamp irradiation. The DRS results indicate that the absorption of ZnO/CPAN nanocomposites in the visible region was significantly higher than that of pure ZnO nanoparticles. The TEM results show that the surface of ZnO nanoparticles is occupied by the CPAN in small amount. The results of photocatalytic experiment show that the photocatalytic activity of ZnO nanoparticles can be improved significantly by the modification of CPAN. The possible photocatalytic mechanism was also discussed.
关键词： visible light,photocatalytic activity,nanocomposite,ZnO/CPAN
更新于2025-09-10 09:29:36