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La-modified TiO2/carbon nanotubes assembly nanocomposite for efficient photocatalytic hydrogen evolution from glycerol-water mixture
摘要： Lanthanum (La) modified TiO2 embedded over carbon nanotubes (CNTs) to develop nanocomposite for enhanced photocatalytic hydrogen evolution from glycerol-water mixture has been investigated. The samples, synthesized by sol-gel assisted hydrothermal method, were characterized by XRD, FESEM, HRTEM, FTIR, BET, UVeVisible, Raman and PL spectroscopy. La/TiO2 anchored CNTs has larger surface area with uniform distribution of La3+ ions. The performance of hybrid assembly was evaluated in a continuous flow slurry photoreactor system under UVevisible light irradiations. The highest H2 evolution rate of 17265 ppm g-cat-1 h-1 was obtained over 5% La-5% CNTs/TiO2 NRs, 1.14 folds the amount produced over 5% La-5% CNTs/TiO2 NPs, 1.53 time than 5% La/TiO2 and 4.10 folds than using pure TiO2 NPs. This significant improvement in the photo-activity was obviously due to synergistic effect between La and CNTs, larger BET surface area, cleavage of glycerol by La, appropriate band structure, and hindered charges recombination rate. Among the sacrificial reagents, highest H2 evolution was obtained using glycerol due to the presence of a-hydrogen atoms attached to carbon atoms. A correlation between BET surface area and photonic flux in terms of photocatalytic H2 production rate was established to understand the performance of hybrid nanostructures. It was observed that BET surface area and photo-flux utilization for the generation of charge carriers with their efficient separation has significant contribution towards improved H2 production rate. More interestingly, catalyst persisted prolonged stability with a steady H2 production in cyclic runs. This study provides promising pathway for constructing composite of La/TiO2 coupled CNTs for efficient H2 production under visible light.
关键词： La/TiO2,Glycerol,TiO2/CNTs hybrid,H2 production,Visible light,Photo-catalysis
更新于2025-09-23 15:23:52
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Constructing a novel Zn2SnO4/C/AgBr nanocomposite with extended spectral response and improved photocatalytic performance
摘要： High-ef?cient photocatalyst based on Zn2SnO4/C/AgBr multi-component heterostructure was prepared via a two-step hydrothermal synthesis method followed by chemical deposition process. Morphological studies showed that ultra-?ne AgBr nanoparticles with the size of 3e5 nm were in situ grown on the surface of the carbon layers attached to Zn2SnO4 nanocrystals. UVevis characterization demonstrated that the co-modi?cation of carbon and AgBr contributed to the dramatically improved light absorption ability of Zn2SnO4/C/AgBr nanocomposites. In the multi-component heterostructured photocatalyst, carbon functioning as a charge mediator plays a pivotal role in separating photogenerated electron-hole pairs ef?ciently. Zn2SnO4/C/AgBr photocatalysts exhibited a signi?cant enhancement of visible-light photocatalytic performance toward the photodegradation of rhodamine B (RhB), resulting from the synergistic effect of the intensi?ed visible-light absorption capacity and ef?cient photogenerated electron-hole pairs transfer. In addition, a proposed schematic mechanism for the signi?cant enhancement of photocatalytic performance is as well put forward on the basis of the experimental results.
关键词： Photocatalytic degradation,Visible-light,Heterostructure,Zn2SnO4/C/AgBr
更新于2025-09-23 15:23:52
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Visible light photocatalytic mineralization of bisphenol A by carbon and oxygen dual-doped graphitic carbon nitride
摘要： A facile thermal polymerization was applied to synthesize carbon and oxygen dual-doped graphitic carbon nitride (MACN) with controllable electronic band structure using malonic acid and urea as precursors. The C and O atoms substituted the sp2 N atom in graphitic carbon nitride (CN). The 1MACN (1 represented that the weight ratio of malonic acid to urea is 1% during the synthesis) with optimal band structure could decompose 15 ppm bisphenol A (BPA) within 150 min, and the mineralization rate reached to 52%. The superior photocatalytic performance of 1MACN was mainly ascribed to electronic band structure together with optical properties. On the one hand, the formation of delocalized big p bonds favored the electrons transfer after the introducing of carbon atoms. On the other hand, a positive charge density existed on the C atoms because of high electronegativity of contiguous O (3.44) that substituted N compared with C (2.55), which could attribute to high activity of MACN catalyst. The study will contribute to the further improvement of visible-light photocatalytic BPA degradation and mineralization.
关键词： BPA mineralization,Carbon-oxygen dual-doping,Visible-light photocatalytic,Graphitic carbon nitride
更新于2025-09-23 15:23:52
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Photocatalytic treatment of palm oil mill effluent by visible light-active calcium ferrite: Effects of catalyst preparation technique
摘要： Palm oil mill effluent (POME) is a serious and expensive environmental problem in Malaysia. In this paper, CaFe2O4 is introduced as a novel photocatalyst for the degradation of POME under visible light irradiation. Two synthesis routes, auto-combustion and co-precipitation, and two calcination temperatures 550 °C and 700 °C were used to produce four CaFe2O4 catalysts AC550, AC700, CP550 and CP700. CP550 exhibited the greatest photocatalytic degradation at 56% chemical-oxygen-demand (COD) removal after 8 h of irradiation which dropped to 49% after three consecutive cycles indicating reasonable conversion and high recyclability. BET analysis indicated CP550 had the highest SBET (27.28 m2/g) and pore volume (0.077 cm3/g) which dropped precipitously for CP700 upon increasing the calcination temperature to an SBET of 9.73 m2/g and pore volume of 0.025 cm3/g due to annealing which created a smoother surface area as evidenced by the SEM images. UV–Vis DRS indicated CP550 had the highest band-gap (1.52 eV) which is likely due to the presence of a highly crystalline pure CaFe2O4 phase compared to the other products which existed as a mixture of Fe oxidation states evidenced by the XRD data. The PL spectra for all catalysts indicated significantly lower recombination rate for both CP550 and CP700. Introduction of IPA into the reaction mixture to eliminate hydroxyl radicals resulted in a diminishing of COD removal from 56% to 7% proving hydroxyl radicals to be the primary reactive species responsible for photodegradation of POME.
关键词： Co-precipitation,POME,Photocatalysis,Visible light,Calcium ferrite,Auto-combustion
更新于2025-09-23 15:23:52
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High efficient catalytic degradation of tetracycline and ibuprofen using visible light driven novel Cu/Bi2Ti2O7/rGO nanocomposite: Kinetics, intermediates and mechanism
摘要： The photoexcited charge carriers trapping was an effective way to generate a large number of active species like O2?? and ?OH radicals to oxidize pharmaceutical molecules. In ternary Cu/Bi2Ti2O7/rGO composite Cu nanoparticles and rGO sheets act as charge carrier trappers and the suppression of e--h+ pair recombination was confirmed by Photoluminescence analysis. The Cu/Bi2Ti2O7/rGO composite exhibited higher photocatalytic degradation efficiency for degradation of ibuprofen and tetracycline molecules under visible light irradiation within 90 min. Therefore, this research designates a promising strategy for higher photoexcited charge carrier trapping photocatalyst design for efficient degradation of pharmaceutical molecules.
关键词： Nanocomposite,Visible light-driven,Hydrothermal,Pharmaceutical contamination.,Charge carrier trappers
更新于2025-09-23 15:23:52
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Creation of passivated Nb/N p-n co-doped ZnO nanoparticles and their enhanced photocatalytic performance under visible light illumination
摘要： Passivated niobium/nitrogen (Nb-N) p-n co-doped zinc oxide nanoparticles were created by a simple precipitation process with in-situ self-formed NaCl "cage" to confine the nanoparticle growth followed by the heat treatment in a flow of ammonia gas. Enhanced optical absorbance into the visible light region was observed in the Nb/N co-doped ZnO nanoparticle photocatalyst due to the Nb/N co-doping effect. It demonstrated a largely enhanced photocatalytic performance in the disinfection of Escherichia coli bacteria under visible light illumination, which could be attributed to the passivated co-doping of Nb-N to suppress the photogenerated charge carrier recombination on dopants. This robust approach for passivated p-n co-doping may also be applied to other material systems for a wide range of technical applications.
关键词： Nanoparticles,Passivated Nb/N p-n Co-doping,Photocatalyst,Zinc oxide,Visible light
更新于2025-09-23 15:23:52
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Visible Light Communication based Vehicle-to-Vehicle Tracking using CMOS Camera
摘要： This study presents a visible light-communication-based vehicle-to-vehicle tracking system using a new positioning algorithm and modified version of the Kalman filter. In this system, LED head and tail lamps on the vehicles are used to transmit positioning signals to other vehicles. Two CMOS dashboard cameras on each vehicle are used to receive these signals. From the geometric relationship between two cameras and the images of LEDs captured by these two cameras, the instantaneous position of the target vehicle can be determined given that at least one LED of the target vehicle is in the view frame of the two cameras. The discrete positioning result always contains unavoidable errors, which consist of systematic errors caused by the CMOS rolling shutter artifact and the weak spatial separability of the sensor, and other random errors. The contribution of this paper is twofold. First, a new positioning algorithm with two compensation mechanisms is proposed to eliminate systematic errors. Second, a modified Kalman filter is proposed to filter out random errors to achieve a smooth and accurate tracking result for the vehicle position. The performance of the system is verified through simulations.
关键词： tracking,vehicle,Kalman filter,visible light communication,camera
更新于2025-09-23 15:23:52
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Fabrication of high efficiency visible light Z-scheme heterostructure photocatalyst g-C3N4/Fe0(1%)/TiO2 and degradation of rhodamine B and antibiotics
摘要： We have prepared and studied a novel low cost catalyst of g-C3N4/Fe0(1%)/TiO2, using a simple process involving the formation of zero valence iron by chemical reduction. This ternary catalyst g-C3N4/Fe0(1%)/TiO2 was characterized using XRD (X-Ray diffraction), UV–vis spectrum, EDS (Energy Dispersive spectrum) and TEM (transmission electron microscopy), it demonstrated high-visible-light activity in a wide range of pH condition, it can photo-catalytically degraded Rhodamine B (RhB), Tetracycline (TC), and Berberine hydrogen chloride (BH) (～98% in 90 min) under visible light. The high activity arises from the increased harvest of more visible light and the improved separation of photo-excited electrons and holes via Z-scheme and heterojunctions mechanism. Also, the time required to remove 100% RhB, TC, and 96% BH can be shortened from 90 min to 60 min by introducing 3.18 mM Na2SO3 to this photocatalysis system that assisted the generation of reactive oxidizing species and pollutant degradation. The results showed promising application prospect for this developed catalyst and the tested photocatalysis pollutant degradation system.
关键词： Antibiotics,z-scheme heterostructure,Rhodamine B,g-C3N4/Fe0(1%)/TiO2 photocatalyst,Visible-light
更新于2025-09-23 15:23:52
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TiO2/MoS2 heterojunctions-decorated carbon fibers with broad-spectrum response as weaveable photocatalyst/photoelectrode
摘要： The development of efficient and recyclable photocatalysts with wide spectrum response has drawn much attention. Herein, we prepared TiO2/MoS2 heterostructures on carbon fibers (CFs) by a two-step hydrothermal method. CFs/TiO2/MoS2 exhibits a strong and wide absorption spectrum from ultraviolet to near-infrared region (> 1200 nm). Under the irradiation of visible-light, CFs/TiO2/MoS2 could degrade 97.6% Rhodamine B (RhB) after 100 min, 94.2% Acid Orange 7 (AO7) or 93.4% tetracycline hydrochloride (TC) after 60 min, and 88.7% 4-chlorophenol (4-CP) after 180 min. Moreover, CFs/TiO2/MoS2 bundles can be further weaved into a cloth (area: 4 × 4 cm2). CFs/TiO2/MoS2 cloth as a working electrode exhibits significant photocurrent (7.53 × 10?6 A/cm2) and enhanced photoelectrocatalytic efficiency (100% TC) comparing with only photocatalysis (90.7% TC) or electrocatalysis (47% TC). In particular, CFs/TiO2/MoS2 cloth shows excellent stability. Therefore, CFs/TiO2/MoS2 cloth has great potential to be used as flexible and weaveable photocatalyst/photoelectrode for degrading various pollutants.
关键词： Photoelectrocatalysis,Photocatalyst,Carbon fibers,Visible-light,TiO2/MoS2
更新于2025-09-23 15:23:52
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One-pot synthesis of visible-light-driven photocatalyst for degradation of Rhodamine B: graphene based bismuth/bismuth(III) oxybromide
摘要： A ternary photocatalyst, graphene based bismuth modified bismuth(III) oxybromide (Bi/BiOBr/G), was synthesized via a facile one-step solvothermal method using only ethylene glycol as both solvent and reducing reagent. Bi/BiOBr/G exhibits higher photocatalytic activity than bismuth(III) oxybromide (BiOBr) on degradation of Rhodamine B under visible-light illumination, and the photodegradation rate is 4.9 times that of BiOBr. The enhanced photocatalytic activity is attributed to the synergistic effect among Bismuth, graphene and BiOBr, which can effectively promote the visible-light absorption of Bi/BiOBr/G and the separation of photogenerated charge carriers. The conditions influencing the photocatalytic performance of Bi/BiOBr/G were also investigated in detail, as well as the photocatalytic mechanism of the degradation.
关键词： Nanocomposites,Semiconductors,Carbon materials,Photocatalytic activity,Visible light
更新于2025-09-23 15:23:52