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Core-shell type Tourmaline@ZnO composites equipped with carbon dots for high efficiency photocatalyst
摘要： Here we report that a novel type of Tourmaline@ZnO core-shell composite equipped with carbon dots (CDs) as multi-band light active sensitizer has been successfully designed and efficiently utilized as the superior photocatalyst towards the degradation of methyl orange (MO) under Xenon lamp at room temperature. The bare ZnO, CDs/ZnO, Tourmaline@ZnO and CDs/Tourmaline@ZnO were systemically synthesized following the facile homogeneous precipitation process and characterized in detail by XRD, FTIR, FESEM, HRTEM, UV-Vis, PL, PC and EIS investigations in succession. Bare ZnO displays as 3-dimensional hierarchical nano-flowers with large specific surface area reaching up to 62.049 m2/g by BET measurement, while the other composite products confirm the core-shell structures with CDs inlaying on ZnO layer surfaces. The photocatalytic activities of the polynary hybridations obtain effective enhancements compared to pure ZnO, the ternary system (CDs/Tourmaline@ZnO) deserves more attention for achieving the maximum (91.25%). It should been the synergistic effect on the highly efficient catalysis performances exerting by the presence of CDs modifier and the Tourmaline core, which make ZnO matrix receive more photo-generated electrons and broaden the visible light response originated from CDs, and synchronously hinder the recombination of electrons-hole pairs by the spontaneous polarization and surface electric field of Tourmaline.
关键词： Tourmaline,photocatalysis,ZnO,core-shell,CDs
更新于2025-09-23 15:23:52
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Enhanced solar light driven activity of p-n heterojunction for water oxidation induced by deposition of Cu2O on Bi2O3 microplates
摘要： As an important half reaction in solar-driven water splitting, it is more challenging to develop low-cost and highly efficient photocatalysts for water oxidation. The enhancement of sunlight harvesting and inhibition of charge-carrier recombination are keys to fabricating efficient semiconductor-based photocatalysts for energy conversion from solar light to chemicals. Herein, we reported highly dispersive Cu2O/Bi2O3 composites prepared by a facile and benign synthetic route, where n-type Bi2O3 microplates and nano-sized p-type Cu2O were coupled together to construct heterojunctions to improve the transportation efficiency of photoinduced charge carriers, benefited from the intimate interactions at the interfaces between Bi2O3 and Cu2O. The electrochemical properties of charge-transportation and population of charge carriers were investigated in the heterojunctions. The hybrid materials exhibit both enhanced photocatalytic performances in water oxidation and photodegradation of dyes compared with sole Bi2O3 or Cu2O under artificial solar light irradiation. The initial O2 evolution rate of the heterojunction system is 1.4- and 8-fold higher than the pure Bi2O3 and Cu2O, respectively. This study provides new protocols for synthesizing novel hybrid materials with insights into heterojunction-based photocatalysis for green energy production and wastewater purification.
关键词： Nanocomposite,Water oxidation,Photocatalysis,Heterojunction,Wastewater purification
更新于2025-09-23 15:23:52
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Copper-doped hybrid Agx–Auy@ZnO nanoparticles and their enhanced photocatalytic activities
摘要： In this paper, we report on the simple polyol synthesis of copper-doped hybrid Agx–Auy@ZnO photocatalysts. The obtained samples have been characterized by X-ray diffraction, UV–Vis diffuse reflectance spectroscopy, transmission electron microscopy and an N2 adsorption study. The experiment results show that Ag, Au and Ag–Au alloy nanoparticles (NPs) successfully load onto the surface of the assembled Cu-doped ZnO. The photocatalytic performances of Cu-doped Agx–Auy@ZnO nanomaterials have been tested using diuron herbicide as a model contaminant under simulated solar light irradiation. The addition of Ag and/or Au nanoparticles to doped ZnO was strongly beneficial to the rate constant displaying a volcano-like pattern as a function of the Ag and Au content. A maximum pseudo-first-order rate constant of 18.55 × 10?3 min?1, 22.70 × 10?3 min?1 and 24.74 × 10?3 min?1 was achieved on Cu-doped Ag0.3@ZnO, Au0.5@ZnO and Ag0.5–Au0.3@ZnO respectively. The Cu-doped Ag0.5–Au0.3@ZnO bimetallic nanoparticles show the highest photocatalytic activity due to the synergistic effect by effective electron transfer.
关键词： Hybrid photocatalyst,Copper-doped,Diuron,Water treatment,Polyol process,One pot,Zinc oxide,Gold,Photocatalysis,Solar light,Silver
更新于2025-09-23 15:23:52
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A brief survey of the practicality of using photocatalysis to purify the ambient air (indoors or outdoors) or air effluents
摘要： This survey attempts to evaluate the possibilities of using heterogeneous photocatalysis to purify air in the three title domains. Regarding indoor air, the formation of degradation intermediate products, some of which can be toxic or irritating, is the key issue for obvious safety reasons. Accordingly, commercializing individual purifiers is questionable because their management cannot securely be left to the user’s responsibility. When the purifier is incorporated in air ducts, adequate control can possibly be achieved permanently via proper sensors automatically adjusting the air flow to always deliver healthy air; also, if the pressure drop enables it, an adsorbing filter before air admission in the occupied spaces could be added. The main issue would then be the cost, which depends on the photocatalyst efficacy and its gradual decrease essentially due to solid deposits (including SiOx formed from Si-containing compounds present in the air). Regarding outdoor air, the rates are inherently low because of the scanty percentage of UV radiation in sunlight. Above all, because of the obvious need for the pollutants to be transferred to the photocatalytic surfaces, a potential significant effect of photocatalysis will be limited to rare confined spaces. Additionally, the deposition of dirt and photocatalytically-formed inorganic salts - which can accumulate in rain-sheltered locations - will further decrease over time the already low efficacy. Hence, the interest of photocatalytic materials for purifying outdoor air seems moot, despite some claims. Regarding air effluents, the practicality of the photocatalytic treatment obviously depends on the effluent contents in pollutants and water vapor, the volume to be treated, and the requested quality of the treated air. If, after trials, the treatment is thought to be economically viable for the targeted effluent, the industrial environment will enable the necessary monitoring. Nevertheless, research aiming at improving the reactor design, the photocatalyst activity and lifetime, and, possibly, the sunlight use, can be needed for competing more efficiently with well-established processes on a case-by-case basis.
关键词： Photocatalysis. Indoor air. Outdoor air. Air effluents. Air purification
更新于2025-09-23 15:23:52
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Conjugated donor-acceptor polymer photocatalysts with electron-output “tentacles” for efficient hydrogen evolution
摘要： The tunable structures and versatile properties for conjugated polymers (CPs) make them viable as a molecular platform for photocatalytic water splitting. Normally, structure design of polymer photocatalyst is focus on tuning its optical band structure or charge-separation ability, the importance of electron-output ability in photocatalytic process is always ignored. This study demonstrates a molecular engineering strategy by introducing an electron-output “tentacle” site, i.e. dibenzothiophene-S,S-dioxide (FSO) unit, into the polymer backbone to construct a series of donor-acceptor type conjugated polymer photocatalysts for efficient hydrogen evolution, which not only results in optimized light absorption ability and excellent exciton-separation, but also leads to the efficient electron-output ability. Detailed DFT calculations further theoretically confirm the vital role of FSO unit as an electron-output “tentacle” site.
关键词： Conjugated polymer,Electron-output “tentacles”,Artificial photosynthesis,Hydrogen evolution,Photocatalysis
更新于2025-09-23 15:23:52
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Photocatalysis removing of NO based on modified carbon nitride: The effect of celestite mineral particles
摘要： Atmospheric NO is one of the toxic and hazardous gases. Its’ levels are continually rising in recent years. As we known, mineral particles contained in the atmosphere may affect the photocatalytic NO removal process. In this study, we found that celestite modification could greatly improve the activity (about 3.8 times) and stability of g-C3N4 for the photocatalytic NO removal. In our system, celestite particles embed in the N vacancies of g-C3N4. The synergistic effect of celestite and N vacancy is the origin of improved NO removal activity. During the light irradiation, photogenerated electrons can be captured and confined by N vacancy. Meanwhile, celestite can transfer these confined electrons to O2 and produce more ·OH, which could oxidize NO to nitrate. These findings can help us to understand the influence of mineral particles in the photocatalytic NO removal and design highly efficient NO removal phtocatalysts.
关键词： NO removal,g-C3N4,Photocatalysis,Celestite,Mineral particles
更新于2025-09-23 15:23:52
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α-NiS/Bi <sub/>2</sub> O <sub/>3</sub> Nanocomposites for Enhanced Photocatalytic Degradation of Tramadol
摘要： In this study, a series of α-NiS/Bi2O3 composite nanomaterials were prepared and evaluated as efficient photocatalyst for degradation of tramadol under visible light. Two polymorphs of Bi2O3 namely α- (monoclinic) and β- (tetragonal) were prepared by using combustion method and bismuth subcarbonate decomposition route, respectively. A facile method was also developed for synthesis of ultrathin α-NiS nanosheets under mild conditions using hexamethylenetetramine as hydrolyzing agent and Na2S2O3 as sulfur source. The NiS/α-Bi2O3 and NiS/β-Bi2O3 composite materials were thoroughly characterized using a variety of techniques to understand their structural, optical, electrochemical, microstructural and morphological attributes. The α-NiS/Bi2O3 materials exhibited improved visible light absorption, enhanced charge carrier separation and photo-electrochemical properties. The microscopic close contact between the two semiconductor phases is established from the morphological studies. The α-NiS/Bi2O3 materials exhibited excellent photocatalytic activity for aqueous phase degradation of tramadol under visible light irradiation. Particularly, the α-NiS/β-Bi2O3 system is highly active achieving 94% degradation in 3 h. The mechanism of photocatalytic action involves a z-scheme electron transfer from the CB of Bi2O3 to the VB of NiS which is responsible for efficient space separation of charge carriers and their increased reactivity. The ?OH radicals and h+ species have been identified as the major transient species responsible for tramadol oxidation. The photocatalytic method developed in this study can be a viable alternative for TiO2 based UV active photocatalyst studied so far for tramadol degradation.
关键词： Tramadol,Bi2O3,Photocatalysis,α-NiS,Z-scheme
更新于2025-09-23 15:23:52
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Two-dimensional amorphous heterostructures of Ag/a-WO3- for high-efficiency photocatalytic performance
摘要： Synergistic photocatalysis is an important concept for designing the high-efficiency catalysis for fundamental research and technical applications. In this study a well-defined synergistic photocatalysis system is realized by the 2D amorphous heterostructures (2DAHs) Ag/a-WO3-x, which are constructed by Ag nanoparticles on 2D amorphous tungsten oxide (a-WO3-x) fabricated via supercritical CO2 method. We demonstrate theoretically that the oxygen evolution reactions (OER), characterized by photocurrent response, have been dramatically improved in Ag/a-WO3-x than those of both single a-WO3-x and Ag/WO3 systems. Such an enhanced photoelectrochemical performance attributes to the superposition effect of amorphous effect catalysis and local surface plasmon resonances (LSPR) catalysis. More interestingly, the ab initio density-functional theory calculations reveal that the amorphous effect catalysis ascribes to the unique d-d tail states coupling of both Ag and W atoms in the 2DAHs. Overall, our findings not only propose the prototype of synergistic photocatalysis, but also provide a new methodology to the design of novel catalyst.
关键词： 2D amorphous tungsten oxide,amorphous effect catalysis,synergistic photocatalysis,d-d tail states coupling,2D amorphous heterostructures Ag/a-WO3-x
更新于2025-09-23 15:23:52
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Perovskite photocatalyst CsPbBr3-xIx with a bandgap funnel structure for H2 evolution under visible light
摘要： A simple and efficient light-assisted method is employed to prepare powder samples of all-inorganic mixed-perovskite CsPbBr3-xIx from CsPbBr3 by ion exchange in aqueous HBr/KI solution such that the concentration of I in a sample particle decreases on going from the surface to the interior. CsPbBr3-xIx/Pt, namely, CsPbBr3-xIx samples loaded with Pt nanoparticles, shows a high performance for the hydrogen evolution under visible-light irradiation in aqueous HBr solution saturated with CsPbBr3. The H2 evolution rate of the CsPbBr3-xIx/Pt powders (200 mg) is determined to be 224 μmol h-1, under 120 mW cm-2 visible-light (λ ≥ 420 nm) illumination. The CsPbBr3-xIx samples have a high stability, with no apparent decrease in the catalytic activity after 50 h of repeated H2 evolution experiments. The apparent quantum efficiency of CsPbBr3-xIx/Pt is determined to be 2.15% under the irradiation of 450 nm light.
关键词： photocatalysis,hydrogen evolution,bandgap funnel,all-inorganic perovskite,halide gradient
更新于2025-09-23 15:23:52
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Simultaneous Cr(VI) removal and bisphenol A degradation in a solar-driven photocatalytic fuel cell with dopamine modified carbon felt cathode
摘要： In this work, a carbon felt cathode modified by dopamine (DPA/CF) was explored to enhance the cathodic reduction of Cr(VI) in a two chambers photoelectrochemical system, which was driven by solar light irradiation using BiVO4 photoanode. In the anode chamber, the bisphenol A (BPA) decomposition can be significantly improved by increasing pH to 8. The electron-hole pairs photogenerated on the surface of BiVO4 were efficiently separated by the application of the DPA/CF cathode. At the optimal conditions, 86% of low-concentration BPA was removed within 60 min. In the cathodic chamber, 80% of Cr(VI) was removed at pH of 4. Based on the XPS and electrochemical analyses, it was proposed that the positively-charged groups on the DPA/CF cathode led to the multilayer adsorption of Cr(VI) anions, which enhanced the reduction of Cr(VI) with the electrons generated on the BiVO4. On the other hand, the CeO groups on the DPA/CF electrode also played an important role as electron transfer mediator for Cr(VI) reduction. The prepared DPA/CF cathode associated with BiVO4 photoanode could be a potential application for efficient removal of Cr(VI) and organic pollutants under solar light irritation.
关键词： BiVO4 photoanode,Carbon felt cathode,Dopamine,Cr(VI),Solar photocatalysis,BPA
更新于2025-09-23 15:23:52