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In suit inducing electron-donating and electron-withdrawing groups in carbon nitride by one-step NH4Cl-assisted route: A strategy for high solar hydrogen production efficiency
摘要： Owing to insu?cient active sites, strongly bound excitons and insu?cient optical absorption, polymer semiconductors have only shown mild activity as potential candidates for photocatalysis. A g-C3N4 with improved optical absorption capacity, charge transfer performance and porosity was successfully prepared by a one-step NH4Cl-assisted route. Interaction of melamine with NH4Cl preparation of Porous g-C3N4(CN-xy) with active functional groups modi?ed pore wall shown to result in highly crystalline species with a maximum π-π layer stacking distance of heptazine units of 0.321 nm, decreases the optical band gap from 2.80 to 2.13 eV and maximum surface area reached 56.485 m2 g?1. The balanced improvement of the multiple defects of g-C3N4 makes the photocatalytic degradation of RhB and the photocatalytic hydrogen production e?ciency 4 and 5 times higher than the pristine g-C3N4, respectively.
关键词： Photocatalytic,g-C3N4,Porous,Trade-o?,Active functional groups
更新于2025-11-19 16:46:39
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Growth Process and CQDs-modified Bi4Ti3O12 Square Plates with Enhanced Photocatalytic Performance
摘要： Bi4Ti3O12 square plates were synthesized via a hydrothermal route, and their growth process was systematically investigated. Carbon quantum dots (CQDs) were prepared using glucose as the carbon source, which were then assembled on the surface of Bi4Ti3O12 square plates via a hydrothermal route with the aim of enhancing the photocatalytic performance. XRD (X-ray powder diffraction), SEM (scanning electron microscopy), TEM (transmission electron microscopy), UV-vis DRS (diffuse re?ectance spectroscopy), XPS (X-ray photoelectron spectroscopy), FTIR (Fourier transform infrared spectroscopy), PL (photoluminescence) spectroscopy, EIS (electrochemical impedance spectroscopy) and photocurrent spectroscopy were used to systematically characterize the as-prepared samples. It is demonstrated that the decoration of CQDs on Bi4Ti3O12 plates leads to an increased visible light absorption, slightly increased bandgap, increased photocurrent density, decreased charge-transfer resistance, and decreased PL intensity. Simulated sunlight and visible light were separately used as a light source to evaluate the photocatalytic activity of the samples toward the degradation of RhB in aqueous solution. Under both simulated sunlight and visible light irradiation, CQDs@Bi4Ti3O12 composites with an appropriate amount of CQDs exhibit obviously enhanced photocatalytic performance. However, the decoration of excessive CQDs gives rise to a decrease in the photocatalytic activity. The enhanced photocatalytic activity of CQDs-modi?ed Bi4Ti3O12 can be attributed to the following reasons: (1) The electron transfer between Bi4Ti3O12 and CQDs promotes an ef?cient separation of photogenerated electron/hole pairs in Bi4Ti3O12; (2) the up-conversion photoluminescence emitted from CQDs could induce the generation of additional electron/hole pairs in Bi4Ti3O12; and (3) the photoexcited electrons in CQDs could participate in the photocatalytic reactions.
关键词： photocatalytic mechanism,photodegradation of RhB,CQDs@Bi4Ti3O12 composites,Bi4Ti3O12 square plates,CQDs
更新于2025-11-19 16:46:39
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Binary composites WO3/g-C3N4 in porous morphology: Facile construction, characterization, and reinforced visible light photocatalytic activity
摘要： Various WO3/g-C3N4 binary composites were constructed by a facile one-step calcination procedure and then systematically analyzed for chemophysical properties. Interestingly, these resultant composites showed porous morphology in combination with some tubular structures, where both components were closely contacted to generate heterojunction structures. Accordingly, these composites possessed reinforced visible-light absorption capability and enlarged specific surface areas in texture. These microstructural, morphological, and electronic merits ensured the strengthened photocatalytic performance toward degradation of rhodamine B (RhB) and methylene blue (MB) under visible light irradiation. In addition, on base of reactive species entrapping experiments and analytical results, a probable photocatalysis mechanism was speculated as a “Z-scheme” manner instead of conventional Type II path.
关键词： WO3,Photocatalytic degradation,Mechanism,Porous morphology,Binary composites,g-C3N4
更新于2025-11-14 17:04:02
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Laser-induced synthesis and photocatalytic properties of hybrid organic–inorganic composite layers
摘要： A laser-based method was developed for the synthesis and simultaneous deposition of multicomponent hybrid thin layers consisting of nanoentities, graphene oxide (GO) platelets, transition metal oxide nanoparticles, urea, and graphitic carbon nitride (g-C3N4) for environmental applications. The photocatalytic properties of the layers were tested through the degradation of methyl orange organic dye probing molecule. It was further demonstrated that the synthesized hybrid compounds are suitable for the photodegradation of chloramphenicol, a widely used broad-spectrum antibiotic, active against Gram-positive and Gram-negative bacteria. However, released in aquatic media represents a serious environmental hazard, especially owing to the formation of antibiotic-resistant bacteria. The obtained results revealed that organic, urea molecules can become an alternative to noble metals co-catalysts, promoting the separation and transfer of photoinduced charge carriers in catalytic composite systems. Laser radiation induces the reduction of GO platelets and the formation of graphene-like material. During the same synthesis process, g-C3N4 was produced, by laser pyrolysis of urea molecules, without any additional heat treatment. The layers exhibit high photocatalytic activity, being a promising material for photodegradation of organic pollutants in wastewater.
关键词： transition metal oxide nanoparticles,urea,photocatalytic properties,hybrid organic–inorganic composite layers,graphene oxide,graphitic carbon nitride,methyl orange,laser-based synthesis,chloramphenicol
更新于2025-11-14 17:04:02
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NiSe as an effective co-catalyst coupled with TiO2 for enhanced photocatalytic hydrogen evolution
摘要： Construction of semiconductor heterojunctions can effectively accelerate the separation of photo-induced charge carriers and thereby enhance photocatalytic activity. Here, NiSe was used as an effective co-catalyst to construct an active NiSe/TiO2 heterojunction for improving the photocatalytic H2 production of TiO2. The resultant 10%NiSe/TiO2 heterojunction exhibited 11 times higher photocatalytic H2-production activity than that of bare TiO2. The NiSe/TiO2 heterojunction and the photo-reduction of partial Ni2t to Ni0 notably accelerated the separation and transfer of photo-excited electron-hole pairs, and thus resulted in obvious improvement of H2-evolution activity. This work holds promise for the application of NiSe in photocatalysis as a high-efficiency photocatalytic cocatalyst.
关键词： NiSe/TiO2,Photoreduction,Heterojunction,Metal Ni0,Photocatalytic H2 evolution
更新于2025-11-14 17:04:02
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Influence of water-controlled release process on the physical and chemical property of nanosize TiO <sub/>2</sub> particles
摘要： The water-controlled release process (WCRP) was utilized for the synthesis of TiO2 photocatalyst. The effect of alkylated esterified WCRP system on the morphology, specific surface area (SSA) and photocatalytic activity of TiO2 were studied systematically. By changing the structure of alcohol and acid involved in the esterification reaction, we found that the SSA and photocatalytic activity of TiO2 obtained in an ethanol/acetic acid reaction mixture showed the best results. Interestingly, the TiO2 obtained in t-butanol/acetic acid contains both the anatase and rutile phase, while the other systems only possessed anatase phases. The conditions of ethanol and acetic acid esterification were optimized and the experimental results showed that the SSA of nano-TiO2 was improved by shorting the reaction time or adding an organic solvent, which can form an azeotrope with water, but no effect on the photocatalytic activity could be observed. The reaction mechanism of esterified WCRP system was furthermore studied by NMR spectroscopy, showing three kinds of reaction, namely esterification, etherification and hydrolysis.
关键词： water-controlled release process(WCRP),p-toluenesulfonic acid,esterification,photocatalytic,titania
更新于2025-11-14 17:04:02
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Plasmonic Au nanoparticles supported on both sides of TiO2 hollow spheres for maximising photocatalytic activity under visible light
摘要： A strategy of intensifying the visible light harvesting ability of anatase TiO2 hollow spheres (HSs) was developed, in which both sides of TiO2 HSs were utilised for stabilising Au nanoparticles (NPs) through the sacrificial templating method and convex surface-induced confinement. The composite structure of single Au NP yolk-TiO2 shell-Au NPs, denoted as Au@Au(TiO2, was rendered and confirmed by the transmission electron microscopy analysis. Au@Au(TiO2 showed enhanced photocatalytic activity in the degradation of methylene blue and phenol in aqueous phase under visible light reference materials such as surpassing that of other Au(TiO2 by 77% and Au@P25 by 52%, respectively, in phenol degradation.
关键词： confinement,photocatalytic degradation,visible light,TiO2 hollow spheres,plasmonic Au nanoparticles
更新于2025-11-14 17:04:02
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One-pot synthesis of 3D Cu <sub/>2</sub> S–MoS <sub/>2</sub> nanocomposites by an ionic liquid-assisted strategy with high photocatalytic activity
摘要： Novel 3D Cu2S–MoS2(x : y) nanocomposites with different proportions of Cu2S (x) and MoS2 (y) are synthesized successfully by a one-step hydrothermal method with the assistance of the ionic liquid [BMIM]SCN. The characterization results show that the nanocomposites are self-assembled from nanosheets of Cu2S and MoS2, they display nanoflower morphology and a typical mesoporous structure. The fabrication mechanism of the nanocomposites is investigated using time-dependent experiments, which indicate the key role of the ionic liquid (IL) in the synthesis process. Furthermore, TAA is used as a sulfur source instead of the IL to form a Cu2S–MoS2 nanocomposite, with the aim of further investigating the effects of the IL on the morphology of the composite. Photodegradation of MB under visible light irradiation experiments were used as probe reactions to evaluate the photocatalytic performance of the as-prepared samples. All the nanocomposites show better catalytic activity than Cu2S and MoS2 monomers. Among the different Cu2S–MoS2(x : y) nanocomposites, the Cu2S–MoS2(1 : 1) composite exhibits the most excellent photocatalytic performance and cycling stability.
关键词： Cu2S–MoS2 nanocomposites,hydrothermal synthesis,photocatalytic activity,ionic liquid,methylene blue degradation
更新于2025-11-14 17:04:02
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Visible-light-triggered generation of persistent radical anions from perylenediimides: A substituent effect and potential application in photocatalytic reduction of Ag+
摘要： Three perylenediimide derivatives were reduced to their persistent radical anions in N-methyl-2-pyrrolidone (NMP) under ambient conditions by a visible light photoinduced electron transfer (PET). UV?vis and electron paramagnetic resonance (EPR) measurements were carried out to confirm the formation of radicals. The relationships between molecular structure, electrochemical property, phototransformation kinetics, and air stability of radical anions were investigated by the introduction of pyrimidine rings at the core position and fluoroalkylation substituents at the imide position. This study reveals that the electron-deficient pyrimidine rings and electron-withdrawing fluoroalkylation substituents can effectively enhance the phototransformation rate and the radical stability at ambient conditions. The effects of solvents and illuminance levels on the photoinduced reduction of perylenediimides were also studied. A photocatalytic reduction of Ag+ was successfully carried out using the perylenediimide with pyrimidine and fluoroalkylation substituents as catalyst upon irradiation with visible light.
关键词： Photocatalytic reduction,Perylene diimide derivative,Silver ion,Persistent radical anion,Visible light irradiation
更新于2025-11-14 17:03:37
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A molecular-based design of RGO/TiO2-PAM composite flocculant with photocatalytic self-degrading characteristics and the application of the oil sand tailings flocculant
摘要： Polymer flocculation technology has a very broad application in the flocculation industry of oil sand tailings at present. Nevertheless, the most commonly used commercial polyacrylamide flocculant has problems of low flocculation efficiency and secondary pollution. In this paper, we proposed an organic-inorganic composite flocculant with self-degrading properties for the flocculation treatment of oil sand tailings, which was prepared by photocatalytic surface initiation technique. Further, the functional groups of the materials before and after polymerization composites were characterized by infrared spectrum to explore the polymerization mechanism, the structure was observed by transmission electron microscope, and the molecular weight of polyacrylamide was measured by gel permeation chromatography. Then, the flocculation performance was characterized by the flocculation experiment (tested with simulated oil sand tailings). Subsequently, the flocculation mechanism was explored by testing the zeta potential of the organic-inorganic composites and analyzing images of sediment observed by transmission electron microscope and atomic force microscope. Finally, the test of self-degradation performance was carried out under illumination. Based on the above experiments, the following conclusions were obtained. First, the structural characterization results indicate the polymerization mechanism is that under the condition of light, the surface of the inorganic photocatalyst generates free radicals to initiate the radical polymerization of the monomers, so that the monomers successfully grow on the surface of the inorganic particles into comb structure. And then, the flocculation experiment shows that reduced graphene oxide/titanium dioxide-polyacrylamide(2:40) has the best flocculation effect, of which the supernatant transmittance is 21.4 higher and the sedimentation ratio is 8.9% higher than those of the commercial polyacrylamide. The reason for its excellent flocculation performance is that the zeta potential of the organic-inorganic composite increases, reducing repulsion of particles and flocculant molecules, simultaneously, the formed comb structure is beneficial to the expansion of the polymer chain and increases the contact area, thereby improving the flocculation effect. Ultimately, the degradation results indicates that the new organic-inorganic composite had good degradation effect, with the degradation rate up to 75.9% within 4 hours. Therefore, this work has made great contributions to solving the oil sand tailings pollution field.
关键词： Flocculant,Oil sand tailings,Photocatalytic Self-degrading,Organic-inorganic composite,Comb structure
更新于2025-11-14 17:03:37