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Plasmonic and non-plasmonic contributions on photocatalytic activity of Au-TiO2 thin film under mixed UVa??visible light
摘要： A highly photocatalytic Au-TiO2 hybrid thin film was prepared by the photocatalytic deposition of Au nanoparticles (NPs) on reactive sputtered TiO2 thin film. By altering the ratio of the visible (Vis) and ultra-violet (UV) light (Vis/UV) we investigated plasmonic and non-plasmonic contributions of Au NPs to the overall photocatalytic activity. While, a gradual increase of Vis/UV (≤0.24/1) led to a steady enhancement of the photocatalytic performance of Au-TiO2 hybrid structures, further increase in Vis/UV (≥0.30/1) did not foster the enhancement further. At high Vis/UV, plasmon excited electrons seem to start promoting electron-hole recombination in TiO2, which significantly reduces the photocatalytic performance.
关键词： plasmonic,Au,TiO2,nanoparticles,photocatalyst,photoreduction
更新于2025-09-19 17:13:59
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Broadband Photocatalysts Enabled by 0D/2D Heterojunctions of Near-Infrared Quantum Dots/Graphitic Carbon Nitride Nanosheets
摘要： A heterojunction made of 0D near-infrared (NIR)-responsive PbS@CdS@ZnS core@shell@shell quantum dots (PCZ QDs) and 2D graphitic carbon nitride (g-C3N4) nanosheets was rationally constructed herein. In addition to some typical advantages of 0D/2D composites, such as short required charge-diffusion distance and high charge mobility, our designed PCZ QDs/g-C3N4 photocatalysts offer additional beneficial features. The broadband optical absorption of high-quality PCZ QDs highly dispersed on g-C3N4 nanosheets and their strong interaction yield efficient charge transfer between them and endow PCZ QDs/g-C3N4 with high photocatalytic activity from ultraviolet to NIR regions. With the optimized QDs loading levels, the achieved, normalized rate constant is higher than the best-reported value for NIR-driven photocatalysis. PCZ QDs/g-C3N4 possesses good recycling performance and no metal release was detected in the solution after photocatalysis. This work highlights the great potential of QDs/g-C3N4 0D/2D photocatalysts in realizing high-efficiency broadband photocatalysis and functional optoelectronic devices for full solar spectrum exploitation.
关键词： quantum dots,g-C3N4,NIR-responsive,charge transfer,broadband photocatalyst
更新于2025-09-19 17:13:59
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In-situ Homodispersely Immobilization of Ag@AgCl on Chloridized g-C3N4 Nanosheets as an Ultrastable Plasmonic Photocatalyst
摘要： Despite their impressive plasmonic photocatalytic activity, nanosized silver and silver halides always suffer from serious agglomeration and photocorrosion, thus are severely restricted in the practical wastewater restoration applications. The design and realization of plasmonic heterojunction nanostructures is an effective way to solve this stability problem, yet the ideal plasmonic catalyst dispersion and immobilization remains a great challenge. In this work, a highly immobilized Ag@AgCl/g-C3N4 plasmonic photocatalyst was developed through a rational in-situ implanting approach, in which the Ag can be homodispersely distributed and strongly coupled with prefixed Cl sites on g-C3N4 nanosheets (CNNS). The X-ray diffraction (XRD) pattern, X-ray photoelectron spectroscopy (XPS) spectra and element mapping images clearly proved the homodispersely distribution of nanosized Ag@AgCl on the CNNS. The optimal Ag@AgCl-3/CNNS plasmonic photocatalyst with a narrow band gap of 2.45 eV and large specific surface area of 52.9 m2/g performs well in model pharmaceutical wastewater bleaching reactions under visible light. More importantly, the Ag@AgCl-3/CNNS show good stability compared with the conventional inhomogeneously coupled AgCl/g-C3N4 control as verified by their ultralow silver leakage rate in water (0.00152 mg/g·d, accounts 6.9% that of the control) and a much lower corrosion current density (Icorr = 1.63 vs. 3.45 μA), recorded by Tafel slopes. The synergetic effect of surface plasmon resonance effect of nanosized Ag@AgCl with strong visible light harvesting ability and strong coupling between Ag@AgCl and exfoliated porous g-C3N4 nanosheets can support the fast separation of photogenerated electron?hole pairs, thus significantly improving the photocatalytic efficiency in the bleaching of antibiotic pollutants and bacteria. This work affords the great potential of the rational in-situ implanting design for high-performance and stable plasmonic photocatalysts.
关键词： silver leakage control,plasmonic photocatalyst,g-C3N4,Ag@AgCl,ultrastable immobilization
更新于2025-09-19 17:13:59
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BWO nano-octahedron coupled with layered g-C3N4: An efficient visible light active photocatalyst for degradation of cationic/anionic dyes, and N2 reduction
摘要： The challenges like the removal of organic pollutants from the wastewater, and photocatalytic reduction of N2 using solar energy are achievable by stable, low cost, and a visible light active semiconductor mediated photocatalysis. A novel 0.4BWO/g-C3N4 heterostructure achieves excellent degradation of cationic/anionic dyes and N2 reduction under visible light illumination. The 0.4BWO/g-C3N4 exhibits 99.8% degradation efficiency towards the degradation of rhodamine B (RhB), which is 2.2-fold compared to commercial catalyst Degussa P25. 0.4BWO/g-C3N4 composite also efficiently degraded AV7, IC, DB 71 dyes and photo-reduce N2 to NH3. The incorporation of BWO nano-octahedron into the g-C3N4 network suppress the recombination of photogenerated electron-hole pairs and follow Z-scheme electron transfer pathway in 0.4BWO/g-C3N4 heterostructure. The notable separation of electron-hole pairs is well described by photoluminescence, time-resolved fluorescence, and impedance spectroscopy study. The finding presented here provides new insight into typical design and engineering of a stable and visible light active heterostructure for degradation of dyes and N2 reduction.
关键词： Photocatalyst,N2 reduction,Bi3.84W0.16 O6.24,Microwave synthesis,Dye degradation
更新于2025-09-16 10:30:52
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Synthesis of Porous ZnO Nanosheets and Carbon Nanotube Hybrids as Efficient Photocatalysts via Pulsed Laser Ablation
摘要： Zinc oxide (ZnO) has attractive photocatalytic properties. However, the high recombination rate of the photo-excited charge carriers on this material often restricts application. Here, we report that hybridization of one dimensional (1D) carbon nanotubes (CNT) on two dimensional (2D) porous ZnO nanosheets (NS) can be a promising strategy to overcome some of the challenges of ZnO. Specifically, a pulsed laser ablation technique was utilized to hybridize 1D CNT with 2D porous ZnO NS in environmentally friendly as well as super-economic (short time, less than 10 min) conditions. The synthesized ZnO NS-CNT hybrids show a significantly enhanced photocatalytic activity for water splitting relative to their counterpart ZnO NS.
关键词： pulsed laser ablation,water splitting,carbon nanotube,photocatalyst,zinc oxide,nanocomposites
更新于2025-09-16 10:30:52
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The fabrication of a biomass carbon quantum dot-Bi <sub/>2</sub> WO <sub/>6</sub> hybrid photocatalyst with high performance for antibiotic degradation
摘要： A novel biomass carbon quantum dots@Bi2WO6 (BC-QDs@Bi2WO6) photocatalyst with uniform dispersivity was prepared via a dialysis-assisted hydrothermal process. Multiple techniques including HR-TEM, XPS, UV-Vis, PL, photocurrent analysis, and electrochemical impedance spectroscopy were employed to investigate the morphology and structures as well as the optical and electronic properties of the as-prepared samples. The photocatalytic activity of BC-QDs@Bi2WO6 was assessed by the degradation of antibiotics (tetracycline, ciprofloxacin, and gatifloxacin). The improved photocatalytic activity was attributed to the quantum effect of BC-QDs, which acted as the light harvesting center, electron reservoir, and reaction center for degrading the pollutants. Furthermore, a plausible mechanism for photocatalysis was put forward according to the ESR and quenching experiments. The present work can have significant advantages in the construction of biomass carbon-based photocatalysts in pollutant degradation and improved light utilization.
关键词： Bi2WO6,dialysis-assisted hydrothermal process,photocatalyst,biomass carbon quantum dots,antibiotic degradation
更新于2025-09-16 10:30:52
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Polarizability and Catalytic Activity Determine Good Titanium Oxide Crystals but Not Homogeneity in Solar Cells Using Photocatalysts on Both Electrodes
摘要： TiO2 is advantageous when used on the anode of a solar cell (SC) and achieves an electromotive force of 2 V when using another photocatalyst on the cathode (dual-photoelectrode fuel cell). However, both sufficient photocatalytic activity and electronic conductivity are required for the film, and these two requirements compete with each other. Herein, uniformly sized and shaped spheroidal, cubic, and “rhombic” TiO2 nanoparticles were synthesized, forming films using casting, slide, ball milling–slide (BS), and ball milling–mechanical (BD) methods. The AC/DC impedances of the films followed the order “rhombic”-ball milling–slide > “rhombic”-slide > cubic-slide > spheroidal-ball milling–mechanical > P25-casting ~ P25-slide ~ spheroidal-BS ~ spheroidal-slide ~ P25-ball milling–mechanical, demonstrating that “rhombic” and cubic TiO2 films were unsuitable for use on the SC photoanode. The reverse reaction rates of cathode reaction (water photo-oxidation), i.e., the 18O2 exchange reaction, were evaluated, which followed the order Cubic-TiO2 > Spher-TiO2 > Rhomb-TiO2 ~ P25-TiO2, demonstrating that the synthesized TiO2 was unsuitable for water oxidation. Polarizability and catalytic activity of TiO2 crystals were critical to maximize SC performance, and fluorescence peak intensity at 372–366 nm was well correlated to SC performance. P25-Slide on a photoanode at pH 1.78 and BiOCl-Cast on a photocathode at pH 2.00 enabled a maximum power of 85.2 μW cm?2 and an open-circuit voltage of 1.94 V.
关键词： Water oxidation,Impedance,Solar cell,Dual-photoelectrode fuel cell,TiO2,Photocatalyst,Polarizability,Isotope tracing
更新于2025-09-12 10:27:22
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Hydrogen Production System by Light‐Induced α‐FeOOH Coupled with Photoreduction
摘要： Solar driven catalysts on semiconductors to produce hydrogen are considered as a means to solve environmental issues. In this study, H2 production coupling with oxygen consumption by noble metal-free α-FeOOH was demonstrated even though the conduction band edge was lower than the reduction potential of H+ to H2. For activation of α-FeOOH, an electron donor, Hg-Xe irradiation, and low pH (~5) were indispensable factors. The H2 production from H2O was confirmed by GC-MS using isotope-labeled water (D2O) and deuterated methanol. The α-FeOOH synthesized by coprecipitation method showed 25 times more active than TiO2. The photocatalytic activity was stable for over 400 h. Our study suggests that α-FeOOH known as rust can produce H2 by light induction.
关键词： α-FeOOH,Photocatalyst,photoreduction
更新于2025-09-12 10:27:22
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Ti3C2 MXene-derived carbon-doped TiO2 coupled with g-C3N4 as the visible-light photocatalysts for photocatalytic H2 generation
摘要： Photocatalytic hydrogen production is a fascinating clean energy technology to solve the environmental issues and energy crisis. Herein, Ti3C2, a member of MXene, is successfully designed as a precursor for preparing C-TiO2/g-C3N4 photocatalyst without extra carbon addition, and the C-TiO2/g-C3N4 photocatalysts exhibit drastically improved photocatalytic hydrogen generation activity. When the mass ratio of Ti3C2 to g-C3N4 is 10 wt% in the composite, the prepared C-TiO2/g-C3N4 composite photocatalyst shows the highest photocatalytic H2 production activity as high as of 1409 μmol/h/g, which is about 8 times and 24 times higher than the activity of pure g-C3N4 and C-TiO2, respectively. The possible mechanism is assumed that the achieved intimate heterojunction between the Ti3C2 MXene-derived C-doped TiO2 and g-C3N4 can efficiently facilitate the photogenerated charge transfer and inhibit the recombination of electronics and holes, which markedly enhanced photocatalytic hydrogen production activity of C-TiO2/g-C3N4 photocatalysts under visible light.
关键词： MXene,Carbon-doped TiO2,Photocatalyst,Hydrogen production,g-C3N4
更新于2025-09-12 10:27:22
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A tunable synthesis of either benzaldehyde or benzoic acid through blue-violet LED irradiation using TBATB
摘要： In this paper, a highly efficient, metal-free, and homogeneous photooxidative-desilylation of tert-butyldimethylsilyl ethers (TBDMS) in the presence of tetrabutylammonium tribromide (TBATB) under irradiation of visible light was reported. The light source: blue (460 nm) and violet (400 nm) LED, can control selective oxidation to aldehyde or carboxylic acid.
关键词： tetrabutylamonium tribromide,benzyl alcohol,metal-free,tunable synthesis,oxidative-desilylation,visible light photocatalyst
更新于2025-09-12 10:27:22