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Facile Construction of Defect-rich Rhenium Disulfide/Graphite Carbon Nitride Heterojunction via Electrostatic Assembly for fast Charge Separation and Photoactivity Enhancement
摘要： Graphite carbon nitride (CN) is one of the most researched visible light photocatalysts, but it still cannot be used practically because of its low photoactivity resulting mainly from rapid photogenerated charge recombination. To accelerate charge separation, CN was herein electrostatically assembled with ReS2, a two-dimensional semiconductor to construct heterojunction for the first time. The electrostatic and coordination interactions between CN and defect-rich ReS2 make them close contact to form heterojunctions. The ReS2/CN heterojunction exhibits higher photocatalytic performance in pollutant degradation owing to faster generation of reactive oxygen species than CN, as well as increased visible and near-infrared light absorption because of strong photoabsorption of defect-rich ReS2. The accelerated reactive oxygen species generation for the heterojunction arises from accelerated charge separation, especially fast transfer of holes from CN to ReS2 in assistance of interfacial electric field and great valance-band edge difference. This work provides a novel CN-based heterojunction for photoactivity improvement and illustrates significance of electrostatic attraction in fabricating heterojunctions.
关键词： electrostatic interaction,photocatalytic,rhenium disulfide,graphite carbon nitride,charge separation
更新于2025-11-21 11:03:13
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Facile Synthesis of Luffa Sponge Activated Carbon Fiber Based Carbon Quantum Dots with Green Fluorescence and Their Application in Cr(VI) Determination
摘要： Carbon quantum dots (CQDs) were prepared by a chemical oxidation method using lu?a sponge based activated carbon ?ber as the raw material. The obtained CQDs were well characterized. The ?uorescence quenching e?ect of Cr(VI) ion on CQDs was investigated. The results show that the addition of Cr(VI) changes the intensity of the ultraviolet characteristic absorption peak of CQDs, and causes static quenching of the ?uorescence of CQDs. With the increase in the Cr(VI) concentration, the ?uorescence of CQDs was gradually extinguished linearly.
关键词： Activated carbon ?ber,Lu?a sponge,Cr(VI) determination,Fluorescence quenching,Carbon quantum dots
更新于2025-11-21 11:01:37
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A hybrid nanomaterial with NIR-induced heat and associated hydroxyl radical generation for synergistic tumor therapy
摘要： Although photothermal therapy (PTT) and photodynamic therapy (PDT) are widely commended for tumor treatment recently, they still suffer severe challenges due to the non-specificity of photothermal agents (PTAs)/photosensitizers (PSs) and hypoxic tumor microenvironment. Here, an oxygen independent biomimetic nanoplatform based on carbon sphere dotted with cerium oxide and coated by cell membrane (MCSCe) was designed and synthesized with good biocompatibility, homologous targeting ability, and improved photophysical activity. Notably, MCSCe could realize accumulation of hydrogen peroxide (H2O2) in tumor cells and hyperthermia under single laser (808 nm) irradiation, which were simultaneously utilized by itself to produce more toxic hydroxyl radical (·OH). Resultantly, the synergistic therapeutic effect against tumor cells was obtained under near infrared (NIR) laser irradiation.
关键词： cerium oxide,H2O2 self-accumulation,cell membrane,tumor therapy,carbon sphere
更新于2025-11-21 11:01:37
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Carbon quantum dots/TiO2 nanosheets with dominant (001) facets for enhanced photocatalytic hydrogen evolution
摘要： Carbon quantum dots/TiO2 nanosheets with a majority of (001) facet (CQDs/TiO2-001) samples are successfully prepared via a facile method. Compared to TiO2-001 and CQDs/P25, the synthesized CQDs/TiO2-001 presents a remarkably higher photocatalytic activity for H2 evolution with a considerable stability. XRD, XPS, HRTEM, FESEM, FTIR, Photoluminescence (PL) spectroscopy, Fluorescence spectroscopy and UV–visible reflectance spectroscopy are adopted to investigate the morphology, structure and properties of synthesized CQDs/TiO2-001. The mechanism of the improved photocatalytic activity over CQDs/TiO2-001 is also investigated. The results show that the improved photocatalytic activity over CQDs/TiO2-001 can be attributed to the synergistic effects of TiO2-001 and CQDs: the highly exposed (001) facets of TiO2-001 promote the transportation of photogenerated electrons and the loading of CQDs restrains the recombination of electrons-holes on (001) facets. Meanwhile, the visible-light absorption is extended because the CQDs serve as a photosensitizer and sensitize TiO2-001 through the newly formed TieOeC bond between the CQDs and TiO2-001.
关键词： Carbon quantum dots,TiO2,Photocatalytic H2 evolution,(001) facet
更新于2025-11-21 11:01:37
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Preparation of Ag-AgVO3/g-C3N4 composite photo-catalyst and degradation characteristics of antibiotics
摘要： The degradation of tetracycline by silver vanadate (AgVO3), graphite-like carbon nitride (g-C3N4) and their composites was studied by visible light photocatalysis. Their structures and morphologies were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Their degradation intermediates were analyzed by GC-MS. Nanorod silver vanadate was synthesized by hydrothermal method. The results show that the gap between nanorods is reduced by adding spinning carbon nitride, and the photocatalytic performance of the composite is stronger than that of single material. The reaction rate constants of Ag-AgVO3/g-C3N4 composites were 0.0298 min-1, 2.4 and 2.0 times that of g-C3N4 (K=0.0125 min-1) and AgVO3 (K=0.0152 min-1), respectively. At 120 minutes, the degradation rate of the composites reached 83.6%. The degradation of tetracycline was confirmed by GC-MS, and a possible degradation process was proposed.
关键词： Photo-catalysis,Carbon nitride,Antibiotics,Visible light,Silver vanadate
更新于2025-11-21 10:59:37
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Aminoboronic acid-functionalized graphitic carbon nitride quantum dots for the photoluminescence multi-chemical sensing probe
摘要： This paper reports a highly sensitive photoluminescence glucose sensor based on aminoboronic acid-functionalized carbon nitride quantum dots (g-CNQDs/3APBA) fabricated using melamine and 3-aminophenylboronic acid via a facile two-step synthesis process. By introducing the covalent bonds between g-CNQDs and boronic acid groups, it can be effectively used as “on-off-on” based multi-chemical sensor. The g-CNQDs/3APBA exhibited quantum yields (QYs) as high as 78.5%, which is the highest QYs among fluorescence sensors based on g-CNQDs reported thus far. The material showed a wide linear range of 0 – 10 mM and a detection limit as low as 42 nM with excellent selectivity. In addition, it exhibited comparable performance compared to those of a commercial glucometer in a real blood test. Owing to the excellent bio-imaging properties and low cytotoxicity, g-CNQDs/3APBA is a promising candidate as a sensing material for biomedical and clinical applications.
关键词： quantum dots,glucose sensor,multi-chemical sensor,fluorescence,Graphitic carbon nitride,3-aminophenylboronic acid
更新于2025-11-20 15:33:11
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Synthesis of carbon quantum dots from lac dye for silicon dioxide imaging and highly sensitive ethanol detecting
摘要： This study aimed to improve the fluorescence performance of lac dye by preparing carbon quantum dots in an attempt to diversify the applicability of lac dye in fluorescence detection. The highly photoluminescent (PL) ld-CQDs were synthesized for the first time using lac dye as a precursor by a facile, green, one-pot ethanol thermal method. The ld-CQDs were neither soluble nor dispersed in water, but could be dissolved or dispersed in organic solvents. The ld-CQDs were well dispersed in ethanol with a mean diameter of 1.76 nm and were found to emit a bright yellow fluorescence with an emission wavelength of 570 nm. The quantum yield of ld-CQDs was 0.40, which was a significant 20-fold improvement over the lac dye of 0.02. Meanwhile, ld-CQDs exhibited pH-sensitive and excellent affinity for silicon dioxide without further chemical modification. Further, ld-CQDs could be used to image silicon dioxide since the fluorescence intensity of the ld-CQDs/silicon dioxide composites was significantly improved. Furthermore, the ld-CQDs could be used as a highly sensitive fluorescent probe to detect the ethanol content of commercial wines. In conclusion, this study has demonstrated the novel application of the fluorescence properties of the lac dye, which has utility in visual detection applications and in tracking the detection of silicon dioxide and ethanol.
关键词： novel application,carbon quantum dots,photoluminescent,Lac dye
更新于2025-11-20 15:33:11
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Photocatalytic properties of TiO2@Polymer and TiO2@Carbon aerogel composites prepared by atomic layer deposition
摘要： Monolithic structured TiO2/aerogel composites were prepared from resorcinol-formaldehyde polymer aerogel (RFA) and its carbon aerogel (RFCA) derivative. A resorcinol-formaldehyde hydrogel was synthesized in a sol-gel reaction and transformed into polymer aerogel by supercritical drying. The RFA was converted to carbon aerogel by pyrolysis at 900 °C in dry N2. Amorphous and crystalline TiO2 layers were grown from TiCl4 and H2O precursors by atomic layer deposition (ALD) at 80 °C and 250 °C, respectively, on both RFA and RFCA. The substrates and the composites were studied by N2 adsorption, TG/DTA-MS, Raman, SEM-EDX and TEM techniques. Their photocatalytic activity was compared in the UV catalyzed decomposition reaction of methyl orange dye.
关键词： ALD,photocatalysis,carbon aerogel,TiO2,resorcinol-formaldehyde polymer aerogel
更新于2025-11-20 15:33:11
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Photoluminescence enhancement <i>via</i> microwave irradiation of carbon quantum dots derived from solvothermal synthesis of <scp>l</scp> -arginine
摘要： Photoluminescence enhancement of carbon quantum dots was achieved via solvothermal synthesis followed by microwave irradiation. Nitrogen and phosphorous doped carbon quantum dots were prepared by solvothermal heating of L-arginine with phosphoric acid for 12 hours followed by microwave irradiation for 3 minutes. The photoluminescence enhancement was nearly two fold after microwave irradiation. The morphology, structure, and surface properties were the same for the solvothermal (CQDs-S) as well as after microwave (CQDs-M) irradiation. Thus, the enhancement is attributed to the decrease of surface defects within CQDs, which led to a decrease in the non-radiative transitions. The CQDs were quenched selectively by Fe3+ ions. The quenching led to the fabrication of the fluorescence probe for ferric ion determination. The CQDs-M had a low detection limit of 4.0 nM, while CQDs-S had a limit of 50 nM. This study gives a tool for enhancing photoluminescence quantum yields, which is highly desired for biosensing and bioimaging applications.
关键词： Photoluminescence enhancement,Fluorescence probe,Solvothermal synthesis,Ferric ion determination,Microwave irradiation,Carbon quantum dots
更新于2025-11-19 16:56:42
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Synthesis and Optical Properties of Iodinated Multi-walled Carbon Nanotubes
摘要： This paper reports synthesis and optical properties of iodinated multi-walled carbon nanotubes (MWCNT). Multi-walled carbon nanotubes were synthesized by aerosol – assisted chemical vapor deposition method and iodinated by crystalline iodine under increased pressure (approximately ~20 bar) at 400°C. X-ray diffraction analysis, Raman and Fourier transform infrared spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy were applied to characterize the iodinated MWCNTs.The results proved the presence of iodine atoms in iodinated MWCNTs. UV-VIS absorption and photoluminescence properties have been studied in pristine MWCNTs and iodinated MWCNTs suspensions in ethanol. Firstly, photoluminescence intensity of the iodinated MWCNTs remarkably enhanced with the appearance of C–I bonds on the surface of MWCNTs, due to the high concentration of intercalated iodine atoms (approximately 30 wt %). The photoluminescence intensity enhancement of peaks at 430 and 520 nm is highly dependent on defects formed by C–I bonds.
关键词： C–I bonds,photoluminescence,iodinated multi-walled carbon nanotubes,optical properties
更新于2025-11-19 16:56:42