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Effect of Mo doping and NiFe-LDH cocatalyst on PEC water oxidation efficiency
摘要： The NiFe-layered double hydroxide (LDH) nanosheets were decorated on the surface of doped BiVO4 to structure an integrating photoanode for improving solar photoelectrochemical (PEC) water splitting efficiency, which is a dynamic research topic to solve the energy crisis and remit environmental pollution caused by fossil fuel combustion. The fabricated photoanode exhibits rapid response to visible light, enhances photocurrent density and shows significant cathodic shift compared to BiVO4. Moreover, the measured incident photon-to-current efficiency (IPCE) of the photoanode is comparable to that reported in the literature. The amount of evolution oxygen was measured and the faradaic efficiency produced oxygen was also obtained by comparing the theoretical calculation value. The enhancement is attributed to the increase of the carrier density, the effective separation of photogenerated electron-hole and consuming of the photogenerated holes accumulated at the electrode surface, which has been confirmed by electrochemical impedance spectra (EIS) and the intensity modulated photocurrent spectra (IMPS). The work may offer a promising method for designing a high efficiency and low-cost photoanode.
关键词： NiFe-layered double hydroxides.,BiVO4,Mo-doping,Photoelectrochemical water splitting
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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Layered Double Hydroxides Decorated Graphic Carbon Nitride Film as Efficient Photoanodes for Photoelectrochemical Water Splitting
摘要： In the present work, we investigate the graphic carbon nitride (g-CN) film as photoanode to catalyze the photoelectrochemical (PEC) water oxidation and study the influence of NiCo layered double hydroxides (NiCo-LDH) layer on the performance. The g-CN film with good quality and intimate contact with substrate was in-situ prepared via solvothermal process and subsequent calcination. NiCo-LDH is further decorated on the g-CN film through cathodic electrochemical deposition to work as co-catalyst. The g-CN/NiCo-LDH composite with optimized NiCo-LDH loading amount exhibits a photocurrent of 11.8 μA cm-2 at 0.6 V vs. SCE, which is 2.8 times of bare g-CN. Characterizations and performance tests demonstrate that NiCo-LDH promoted reaction kinetics and charge separation. The results provide an effective strategy to improve the photoelectrochemical water oxidation performance of g-CN through NiCo-LDH co-catalyst. This work to investigate the photoelectrochemical water oxidation is of great significance toward explore the overall water splitting on the g-CN film.
关键词： Layered double hydroxides,Solvothermal process,Photoelectrochemical water oxidation,Co-catalyst,Graphitic carbon nitride
更新于2025-09-23 15:22:29
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Highly Enhanced Photocatalytic Water-splitting Activity of Gallium Zinc Oxynitride Derived from Flux-assisted Zn/Ga Layered Double Hydroxides
摘要： The Ga/Zn-oxynitride solid solution [(GaN)1-x(ZnO)x] is one of the promising visible-light harvesting photocatalysts for overall water-splitting. A series of (GaN)1-x(ZnO)x (0.11 ≤ x ≤ 0.33) are synthesized by calcining the carbonate-type Zn/Ga-LDH precursor with and without sodium carbonate flux at 850 oC for 8 - 14 h under a NH3 gas-flow. The solid solutions without flux are determined to be low in crystallinity but plate-like in morphology with preferred orientation could be observed. On the other hand, those with flux turn out to be better in crystallinity, and eventually exhibit significantly higher photocatalytic activity for overall water splitting under visible-light irradiation than those without flux. In addition, the bandgap energies can also be engineered from 2.57 eV to 2.72 eV by changing the synthetic parameter such as nitridation time. It is, therefore, suggested that the present new approach can offer new opportunities for designing the next generation photocatalytic systems.
关键词： Overall water splitting,Photocatalyst,Gallium Zinc Oxynitride,Layered double hydroxides,Flux
更新于2025-09-23 15:21:21
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Three-dimensional biogenic C-doped Bi2MoO6/In2O3-ZnO Z-scheme heterojunctions derived from a layered precursor
摘要： Novel 3D biogenic C-doped Bi2MoO6/In2O3-ZnO Z-scheme heterojunctions were synthesized for the first time, using cotton fiber as template. The as-prepared samples showed excellent adsorption and photodegradation performance toward the hazardous antibiotic doxycycline under simulated sunlight irradiation. The morphology, phase composition and in situ carbon doping could be precisely controlled by adjusting processing parameters. The carbon doping in Bi2MoO6/In2O3-ZnO was derived from the cotton template, and the carbon content could be varied in the range 0.9–4.4 wt.% via controlling the heat treatment temperature. The sample with Bi2MoO6/In2O3-ZnO molar ratio of 1:2 and carbon content of 1.1 wt.% exhibited the highest photocatalytic activity toward doxycycline degradation, which was 3.6 and 4.3 times higher than those of pure Bi2MoO6 and ZnInAl-CLDH (calcined layered double hydroxides), respectively. It is believed that the Z-scheme heterojunction with C-doping, the 3D hierarchically micro–meso–macro porous structure, as well as the high adsorption capacity, contributed significantly to the enhanced photocatalytic activity.
关键词： Adsorption,ZnInAl-layered double hydroxides (LDH),Bi2MoO6,Biotemplate,Photocatalysis
更新于2025-09-23 15:21:01
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Fabrication and performance analysis of a low cost, Pt free counter electrode using carbon coated ZnAl layered double hydroxide (C/ZnAl-LDH) for dye sensitized solar cells
摘要： Carbon based material represents an e?ective substitute for Pt counter electrodes (CEs) in Dye Sensitized Solar Cells (DSSCs). This study introduces a novel carbon coated ZnAl layered double hydroxides (C/ZnAl-LDH) can be utilised as an e?ective CE in DSSCs. C/ZnAl-LDH was synthesised by the pyrolysis of ZnAl-LDH using glucose solution. The synthesised C/ZnAl-LDH was characterised using TEM, SEM, XRD and BET analysis. The surface roughness of both Pt and C/ZnAl-LDH ?lms were analysed using AFM spectroscopy. C/ZnAl-LDH slurry was pasted uniformly using doctor blade technique onto FTO glass substrate. The electrochemical measurements such as Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and Tafel polarization recommends that C/ZnAl-LDH can be used as a CE due to its good reduction rate of ?I3 comparable with Pt CEs. The photovoltaic parameters were observed to be 0.66 V and 11.97 mA/cm2 for open circuit voltage V(oc) and short circuit current density J(sc) respectively for C/ZnAl-LDH CE. The assembled cell with C/ZnAl LDH CE having power conversion e?ciency (PCE) of 3.18% is comparable to Pt CE having 4.62% which is measured under the similar testing conditions.
关键词： Dye Sensitized Solar Cell,Carbon based material,Counter electrode,Layered double hydroxides,Electrochemical parameters
更新于2025-09-23 15:21:01
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Unassisted Water Splitting Using Standard Silicon Solar Cells Stabilized with Copper and Bi-functional NiFe Electrocatalysts
摘要： Silicon photovoltaic cells functionalized with water splitting electro-catalysts are promising candidates for unassisted water splitting. In these devices, the total surface of silicon solar cell is covered with electrocatalyst causing issues with i) stabilizing silicon solar cell in water and ii) device efficiency due to parasitic optical absorption in electrocatalyst. We describe and validate a water splitting device concept using a crystalline silicon solar cell where the front-side is covered with insulating Si3N5 antireflection coating. The Ag contacts, fired through the antireflection coating, are removed and subsequently substituted with NiFe layered double hydroxide (LDH) or Cu/NiFe-LDH electrocatlysts. In this device only the site of Ag contacts, nearly 2% of total device area is covered by the electrocatalyst. We found this small area of catalyst does not limit device performance and addition of a Cu interlayer between Si and NiFe-LDH improves device performance and stability. The unassisted water splitting efficiency of 11.31%, measured without separating the evolved gases, is achieved using a device composed of three series-connected silicon solar cells and a NiFe-LDH/Cu/Ni-foam counter electrode in a highly alkaline electrolyte.
关键词： NiFe layered double hydroxides,Photoelectrochemical Cells,Unassisted Water Splitting,Crystalline Silicon Solar Cell,Si Photocathodes
更新于2025-09-23 15:19:57
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Crystalline Cooperativity of Donor and Acceptor Segments in Double‐Cable Conjugated Polymers toward Efficient Single‐Component Organic Solar Cells
摘要： Capacitive deionization (CDI) has aroused extensive attention as a prospective technology for different ionic species from aqueous solutions. Traditional studies on the removal adsorption and desorption of fluoride from wastewater are energy-intensive and may have harmful effects on the environment. Herein, the feasibility of fluoride removal from wastewater by CDI has been investigated. NiCoAl-layered metal oxide (NiCoAl-LMO) nanosheets and reduced graphene oxide (rGO) composites (NiCoAl-LMO/rGO) were synthesized and used as CDI electrode materials for fluoride ion removal. The as-obtained NiCoAl-LMO/rGO with unique structure and high conductivity is beneficial to the adsorption of fluoride ions. In addition, the introduction of Co element in the laminate enhances the pseudocapacitive behavior of the electrode material. As expected, the CDI system with NiCoAl-LMO/rGO composites as anode and activated carbon treated by nitric acid (H-AC) as cathode exhibits outstanding defluorination performance. The maximum adsorption capacity of NiCoAl-LMO/rGO, 24.5 mg g?1, can be reached when the initial NaF concentration is 500 mg L?1 at 1.4 V applied voltage. The composites also show good cycle stability over 40 consecutive cycles of the CDI defluorination process. The excellent defluorination performance of NiCoAl-LMO/rGO makes it possible for its practical application in wastewater treatment.
关键词： capacitive deionization,defluorination,layered double hydroxides,NiCoAl-LMO/rGO,removal capacity
更新于2025-09-19 17:13:59
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Development of Zn-Al-Ti mixed oxides-modified cement phases for surface photocatalytic performance
摘要： Recently, several researches have focused on the study of the photocatalytic performance of nanoparticles in concretes and cements. This paper evaluates the photocatalytic activity of Zn-Al-Ti nanoparticles as well as the mineralogical behavior of clinker pastes with the addition of those particles. The samples were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The photocatalytic degradation of methylene blue (MB) was performed under the irradiation of UV light. Different samples were prepared and characterized: clinker pastes with Zn-Al-Ti mixed oxides derived from Layered Double Hydroxides (LDH) synthesized powder additives ranged from 0 to 20 wt. % in pastes, while the water/cement ratio was 0.4. The blend containing 20 wt. % of Zn-Al-Ti mixed oxides has clearly shown the presence of the basic elements of the nanocomposite with important contents which are responsible for photocatalysis process. Experimental results of methylene blue degradation showed that the sample containing 20% of mixed oxides Zn-Al-Ti exhibit enhanced photocatalytic activity, indicating the remarkable efficient separation of photogenerated electrons and holes.
关键词： Clinker,Cement,Layered double hydroxides,Photocatalysis
更新于2025-09-11 14:15:04
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Degradation of Bromate by Fe(II)-Ti(IV) Layered Double Hydroxides Nanoparticles under Ultraviolet Light
摘要： The photocatalytic decomposition of bromate (BrO3-), a possible human carcinogen, has attracted much attention because of its high efficiency and easier combination with ultraviolet (UV) disinfection in water treatment plants. In this study, the Fe(II)-Ti(IV) layered double hydroxides (LDHs) have been made through a facile hydrothermal method and used as an alternative photocatalyst for reduction of BrO3-. LDHs prepared at a Fe/Ti molar ratio of ~0.5 and pH 7.0, denoted as Fe-Ti-0.5 (pH 7.0), exhibited the highest BrO3- removal efficiency (removal rate constant = 0.067 ± 0.002 min-1) compared to commercial TiO2 and the LDHs prepared at different pHs or different Fe/Ti ratios. The presence of alcohols in water enhanced the photocatalytic reduction of BrO3- due to the greater abundance of electrons caused by alcohols effectively reacting with holes. The neutral pH also favors the degradation of BrO3-. However, the presence of nitrate and nitrite can inhibit the degradation process, due to their reactions with hydrated electrons (eaq-) and hydrogen atom radicals (H·). Cyclic degradation runs and magnetic separation techniques demonstrated the superior reusability of the Fe-Ti-0.5 (pH 7.0) LDH for BrO3- removal. The removal rate of BrO3- under UV was higher than that without UV, indicating that the decomposition proceeded primarily via a photo-reductive mechanism induced by eaq- and H· and thus degradation pathways are proposed. Moreover, when tested in tap water, greater than 90% of BrO3- was removed after 60 min reaction in UV/Fe-Ti-0.5 (pH 7.0) LDH systems in the presence of 5‰ (v/v) methanol. This demonstrates the high potential for such systems for removing BrO3- from disinfected drinking water. This work may shed lights on the design of effective photocatalysts for the enhanced degradation of BrO3- in water plants and the influence of constituents in raw water on the treatment.
关键词： Bromate removal,UV/layered double hydroxides system,Alcohols addition,Reductive species,Tap water
更新于2025-09-09 09:28:46