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2D-montmorillonite-dispersed g-C3N4/TiO2 2D/0Dnanocomposite for enhanced photo-induced H2 evolution from glycerol-water mixture
摘要： Montmorillonite (MMT) dispersed g-C3N4/TiO2 hybrid nanocomposite for enhanced photo-catalytic hydrogen production from glycerol-water mixture has been investigated. The newly designed composite photo-catalysts were fabricated through a sol-gel assisted hydrothermal method and were characterized by XRD, XPS, SEM, EDX, TEM, FTIR, UV–Vis, Raman and PL spectroscopy. Well-designed g-C3N4/MMT/TiO2 heterojunction composite was obtained with 2D MMT structure, which promoted both visible light absorption and hindered charges recombination rate. The modification of 2D/0D g-C3N4/TiO2 heterojunction with 2D MMT sheets enhances H2 production due to MMT works as a mediator for effective charges trapping and transportation within the composite structure. The g-C3N4/MMT/TiO2 photo-catalyst exhibits highest H2 production of 4425 ppm h?1 g?1 at pH 7.0, which was 2.12 times higher than the pure TiO2 (2085 ppm h?1 g?1). In addition, increasing catalyst loading promotes more H2 evolution and among the different sacrificial reagents, glycerol-water mixture gave highest H2 production due to the presence of α-hydrogen atoms attached to carbon atoms. The enhanced photocatalytic efficiency can be attributed to synergistic effect of MMT with g-C3N4/TiO2 heterojunction composite, appropriate band structure and transportation of electrons–holes with their hindered recombination rate. These composite catalysts exhibited excellent photo-catalytic stability for H2 production in cyclic runs. Possible reaction mechanism for hydrogen production over g-C3N4/MMT/TiO2 composite has been explained based on the experimental results. The finding of this work would be fruitful for hydrogen production applications with all sustainable systems.
关键词： TiO2,Photo-catalysis,Montmorillonite,g-C3N4,Z-scheme,Hydrogen production
更新于2025-09-23 15:23:52
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Novel Luminescent Multilayer Films with Magnetic and Electronic Microenvironment
摘要： Luminescent multilayer thin films (MTFs) based on exfoliated magnetic layered double hydroxides (LDHs) with/without oppositely-charged montmorillonite (MMT) nanosheets were fabricated via layer-by-layer self-assembly method. In this work, we chose transition metal-bearing LDHs nanosheets to offer magnetic field for the chromophores. At the same time, the oppositely-charged nanosheets can provide additional electronic microenvironment (EME). As a result, both EME and magnetic field have remarkable influences on enhancing the luminescent lifetimes of chromophores, which suggests a new pathway to develop the novel light-emitting materials and optical devices.
关键词： Montmorillonite,Electronic Microenvironment,Magnetic Field,Layered Double Hydroxides,Luminescence
更新于2025-09-23 15:22:29
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A novel “on-off” colorimetric sensor for glutathione based on peroxidase activity of montmorillonite loaded TiO2 functionalized by porphyrin precisely controlled by visible light
摘要： Well-dispersed nanocomposites based on Ca-montmorillonite decorated by porphyrin functionalized titanium dioxide (H2TCPP-TiO2-MMT) was synthesized by a facile strategy. H2TCPP-TiO2-MMT was demonstrated to possess the intrinsic peroxidase-like activity and could catalyze 3’,3’,5’,5’-tetramethylbenzidine (TMB) oxidized by H2O2 accompanied with the color changed from colorless to blue in a short time under visible light irradiating. The optimum experimental conditions, robustness, as well as Michaelis-Menten kinetics was investigated. The fluorescent probe assay indicated the good performance of H2TCPP-TiO2-MMT was attributed to the ·OH radicals from H2O2 decomposition, which was induced by the electron-hole pairs of H2TCPP-TiO2-MMT generated under visible light irradiating. Based on its peroxidase activity, a convenient colorimetric sensor for detecting glutathione (GSH) was proposed. The detection limit for GSH was 0.057 μM, with the linear detection range of 0.1-20 μM. Notably, besides the enhanced peroxidase-like activity, another merit for this sensor was that the reaction time can be controlled accurately by adjusting irradiation time compared with traditional colorimetric sensors, which would benefit the accuracy in detecting GSH. In addition, results of anti-interference and detecting GSH in human serum assays indicated that the H2TCPP-TiO2-MMT was predicted to be one of the promising materials for fast visual colorimetry.
关键词： Peroxidase,Montmorillonite,Porphyrin,Colorimetric assay
更新于2025-09-16 10:30:52
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Fabrication of functionalized plasmonic Ag loaded Bi2O3/montmorillonite nanocomposites for efficient photocatalytic removal of antibiotics and organic dyes
摘要： From the viewpoint of practical application, the development of photocatalyst having strong light harvesting and effective charge separation as well as using abundant natural mineral as photocatalyst substrate would be very promising. In this work, a novel Ag loaded Bi2O3/montmorillonite nanocomposite has been successfully prepared by a facile thermal and impregnation methods for the first time to study its photocatalytic performance for aqueous pollutant decomposition under the visible light irradiation. Interestingly, the Ag loaded Bi2O3/montmorillonite nanocomposite presented excellent visible light induced photocatalytic activities for tetracycline (TC) antibiotic and RhB degradation, which is much superior over those of solely Bi2O3, montmorillonite and the corresponding composite. The superiority photocatalytic performance of Ag loaded Bi2O3/montmorillonite nanocomposite over other samples should be due to the improved visible light absorption, enlarged specific surface area and enhanced charge separation. In addition, the effect of different factors such as dosage of composite, pollutants concentration and pH of the pollutant solution on the photocatalytic activity of the composite was inspected. Finally, the possible photocatalytic mechanism of Ag loaded Bi2O3/montmorillonite nanocomposite towards pollutants was proposed in detail based on the trapping experiment and ESR test. The as-developed composite provides a new high efficiency of photocatalyst for potential applications in refinement antibiotic pollutants from wastewater.
关键词： Silver nanoparticle,Photocatalytic activity,Bismuth oxide,Montmorillonite,Mechanism
更新于2025-09-12 10:27:22
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Enhanced photocatalytic carbon dioxide reforming of methane to fuels over nickel and montmorillonite supported TiO2 nanocomposite using monolith photoreactor
摘要： Conversion of carbon dioxide (CO2) and methane (CH4) to fuels using photo-technology is a cleaner pathway compared to thermal reforming, since its uses only light irradiations, while producing valuable chemicals. In this study, structured nickel (Ni) and montmorillonite (MMT) supported TiO2 composite, synthesized by a sol-gel method, was tested for photocatalytic reduction of CO2 using fixed-bed and monolith photoreactors. The performance of structured nanocatalyst was evaluated using CO2-H2 system via photocatalytic reverse water gas shift (RWGS) reaction and CO2-CH4 system via photocatalytic dry reforming of methane (DRM). Using photocatalytic RWGS, CO was detected as the main products, while the performance of Ni-MMT/TiO2 composite was expressively higher than using MMT/TiO2 and TiO2 catalysts. This was obviously due to larger surface area by MMT dispersion and hindered charges recombination rate by Ni. Similarly, using DRM, H2 and CO were the main products, while their selectivity was greatly dependent on the initial CH4/CO2 molar feed ratios. At a lower CH4/CO2 ratio, more CO was produced, while a higher feed ratio promoted H2 production. This shows, composite catalyst was more favorable for CO2 adsorption, while CH4 was competitively adsorbed during photo-catalysis process. Comparatively, Ni-MMT/TiO2 catalyst reveals higher photo-activity and selectivity in a monolith photoreactor than using fixed-bed reactor under the same operating conditions. This enhanced photoactivity was due to higher photonic flux with enlarged active surface area due to monolithic support and efficient sorption process. The stability of Ni/TiO2 dispersed MMT for CO and H2 production via DRM process sustained in cyclic runs using monolithic support. Hence, using Ni/MMT modified TiO2 catalyst and monolith photoreactor, CO2 and CH4 can efficiently be converted to renewable fuels under light irradiations and would be a great benefit to the environment.
关键词： Photo-technology,Ni/TiO2,Dry reforming of CH4,Monolith photoreactor,Montmorillonite,CO2 reduction
更新于2025-09-04 15:30:14