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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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Acid-treated Ti4+ doped hematite photoanode for efficient solar water oxidation—Insight into surface states and charge separation
摘要： Acid-treatment has been proved to be an efficient approach to improve the photoelectrochemical (PEC) performance of hematite. However, efforts to optimize hematite photoanode have been limited by an inadequate understanding of the semiconductor surface. Here we make efforts to understand the microscopic charge separation processes of Ti4+ doped Fe2O3 photoanode before and after acid-treatment. Surface photovoltage (SPV) transient and the work function measurements directly reveal that acid-treatment leads to passivation of the surface states. Surface photovoltage (SPV) spectroscopic studies coupled to open-circuit photovoltage (OPV) measurements indicate that the surface states of hematite photoanode before acid-treatment result in the pinning of the Fermi level, which reduce the intensity of interfacial electric field at the semiconductor-electrolyte interface.
关键词： Water oxidation,Charge separation,Surface states,Hematite,Acid-treatment
更新于2025-09-23 15:22:29
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Synthesis of low surface-energy polyepichlorohydrin triazoles thin film
摘要： In this investigation, a new polymer with low surface energy was synthesized by grafting a triazole group onto polyepichlorohydrin (PECH) rubber that contained no halogens. The chlorine on PECH was first replaced by an azide group, and this attached azide was then converted to a triazole group with alkyl chains using the azide-alkyne Huisgen cycloaddition reaction. Analyses confirmed the structure of final product, PECH-triazole polymer. The grafting reactions increased the surface roughness. The static contact angles of water or CH2I2 droplets on the PECH-azole film were 101.7° and 71.3°, respectively. The advancing and receding contact angles for water on PECH-azide were 119.8° and 13.7°, respectively. The PECH-triazole polymer has omniphobic properties with rose petal characteristics. The PECH-triazole has low dispersive surface energy (21 mN/m) and negligible non-dispersive surface energy, giving a wetting envelope that is similar to the one of PTFE polymer. X-ray photoelectron spectroscopy and transmission infrared spectroscopy suggested that the interactions of the N atoms on the triazole ring and the O atoms on the PECH backbone constrained the orientation of CH2 groups and reduced the surface energy of the thin film.
关键词： Azide-alkyne Huisgen cycloaddition,Polyepichlorohydrin,Low surface free energy,High water adhesion,Triazole
更新于2025-09-23 15:22:29
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Nanoparticle TiO2 size and rutile content impact bioconcentration and biomagnification from algae to daphnia
摘要： Little information is available about effect of particle size and crystal structure of nTiO2 on their trophic transfer. In this study, 5 nm anatase, 10 nm anatase, 100 nm anatase, 20 nm P25 (80% anatase and 20% rutile), and 25 nm rutile nTiO2 were selected to investigate the effects of size and crystal structure on the toxicity, bioconcentration, and trophic transfer of nTiO2 to algae and daphnia. In the exposed daphnids, metabolic pathways affected by nTiO2 and nTiO2-exposed algae (nTiO2-algae) were also explored. The 96 h IC50 values of algae and the 48 h LC50 values of daphnia were 10.3, 18.9, 43.9, 33.6, 65.4 mg/L and 10.5, 13.2, 37.0, 28.4, 60.7 mg/L, respectively, after exposed to nTiO2-5A, nTiO2-10A, nTiO2-100A, nTiO2-P25, and nTiO2-25R, respectively. The bioconcentration factors (BCFs) for 0.1, 1, and 10 mg/L nTiO2 in daphnia ranged from 21,220 L/kg to 145,350 L/kg. The nTiO2 biomagnification factors (BMFs) of daphnia fed with 1 and 10 mg/L nTiO2-exposed algae were consistently greater than 1.0 (5.7-122). The results show that the acute toxicity, BCF, and BMF all decreased with increasing size or rutile content of nTiO2. All types of nTiO2 were largely accumulated in the daphnia gut and were not completely depurated within 24 h. At the molecular level, 22 Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways of daphnia were impacted by the nTiO2 and nTiO2-algae treatments, including glutathione metabolism, aminoacyl-tRNA biosynthesis, among others. Six and four KEGG metabolic pathways were significantly disturbed in daphnids exposed to nTiO2 and nTiO2-algae, respectively, indicating the presence of algae partially alleviated the negative impact of nTiO2 on metabolism. These findings increase understanding of the impacts of physicochemical properties of nTiO2 on the food chain from molecular scale to that of the whole organism, and provide new insight into the ecological effect of nanomaterials.
关键词： Trophic transfer,Bioaccumulation,Algae,Nanomaterial,Water flea
更新于2025-09-23 15:22:29
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Prussian blue-encapsulated Fe3O4 nanoparticles for reusable photothermal sterilization of water
摘要： Waterborne health issues continue to grow despite the large number of available solutions. Current sterilization techniques to fight with waterborne diseases struggle to meet the demands on cost, efficiency and reach. Effective alternatives are pressingly required. Here we introduce Prussian blue coated ferroferric oxide (Fe3O4@PB) composites for water sterilization. The composites exhibit superior photothermal inactivation of bacteria under solar-light irradiation, with nearly complete inactivation of bacterial cells in only 15 min. Even for the mixed bacteria in authentic water matrices, the composites show excellent bacterial inactivation performance. Moreover, the highly magnetized iron core of the Fe3O4@PB enables magnetic separation and recycling. Multiple cycle runs reveal that Fe3O4@PB composites have exceptional stability and reusability. This work demonstrates a scalable, low-cost, high-efficiency and reusable sterilization method to improve water quality and safety.
关键词： Solar-light irradiation,Prussian blue,Recyclability,Water security,Photothermal sterilization
更新于2025-09-23 15:22:29
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Multifunctional monoclinic VO2 nanorod thin films for enhanced energy applications: Photoelectrochemical water splitting and supercapacitor
摘要： Monoclinic VO2 nanorod thin films were deposited on indium?tin-oxide-coated glass substrates using radio-frequency reactive magnetron sputtering at a substrate temperature of 300 °C and various O2 flow rates. The thin films were characterized via standard analysis techniques. The VO2 thin films exhibited a highly crystalline monoclinic phase with an indirect band gap of ~1.73 eV. At optimized O2 flow rate (4 sccm), the thin films was observed nanorod structures, exhibited a remarkable photocurrent of ~0.08 mA cm?2 during photoelectrochemical water splitting in the visible region. Electrochemical performance tests of the nanorod films revealed a specific capacitance of ~486 mF cm?2 at a scan rate of 10 mVs?1. In addition, amperometric I–t curves showed that VO2 thin film electrodes were highly stable during the photo-oxidation process. The nanorod films also exhibited a good specific capacitance of ~120 mF cm?2 after 5000 cycles at a scan rate of 100 mVs?1. The photocurrents during photoelectrochemical water splitting and the specific capacitance of VO2 thin films deposited at O2 flow rates of 2 and 6 sccm were 0.06 and 0.07 mA cm?2 and 398 and 37 mF cm?2, respectively. The films deposited under Ar at 8 sccm and O2 at 4 sccm showed the highest photoelectrochemical water splitting performance and specific capacitance, owing mainly to their nanorod-like morphology.
关键词： Supercapacitor,Partial pressure,Reactive sputtering,Photoelectrochemical water splitting,VO2,Monoclinic
更新于2025-09-23 15:22:29
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Evidencing enhanced charge-transfer with superior Photocatalytic degradation and Photoelectrochemical water splitting in Mg modified few-layered SnS2
摘要： Recently there has been immense interest in the exploration of richly available two-dimensional non-toxic layered material such as tin disulfide (SnS2) for potential employment in energy and environmental needs. In this regard, we report on the synthesis of few-layered Sn1?xMgxS2 nanosheets through a facile one-step hydrothermal route to address all such functions concerning photocatalysis and photoelectrochemical conversion. The crystalline order and structure of processed layered Sn1?xMgxS2 were initially found to exhibit a strong influence on their physicochemical properties. Their optical properties attest the Mg doping in SnS2 to benefit us with enhanced visible-light absorption via red-shift in their absorption edge. In the photoluminescence spectrum the emissions observed along visible and red region signifies the association of Mg related trap states in Sn1?xMgxS2. Next, the photocurrent and electrochemical impedance spectroscopic results revealed the Mg doping to promote the effective charge transfer process (which was beneficial to enhance their photocatalytic activity). Consequently, the layered Sn0.98Mg0.02S2 made photoanodes displayed 1.7 fold higher photocurrent density under simulated solar radiation with respect to their undoped counterpart. Furthermore, the layered Sn0.98Mg0.02S2 nanosheets exhibits enhanced visible light decomposition of organic dye while compared with pristine SnS2 nanosheets. The value of rate constants obtained for the Sn0.98Mg0.02S2 nanosheets was found to be 1.4 times higher than that of pristine SnS2. Finally, the results obtained through the present study projects the huge potential of layered Sn0.98Mg0.02S2 nanosheets for future multifunctional applications.
关键词： SnS2,Magnesium,Nanosheets,Photocatalysis,Few-layered,Photoelectrochemical water splitting
更新于2025-09-23 15:22:29
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Scalable, eco-friendly and ultrafast solar steam generators based on one-step melamine-derived carbon sponges toward water purification
摘要： Solar steam generation can be a practical and sustainable technology for wastewater purification and seawater desalination. However, both the inefficient utilization of solar energy and high complicity/cost of current solar steam generators hinder the scalable application of this technique. Herein, we demonstrate a facile, scalable and low-cost approach to produce highly-efficient solar steam generator via a one-step calcination of commercial melamine sponges (MS) in air. The in-air calcinated MS (AMS) with thermal insulator achieves an ultrafast solar evaporation rate (1.98 kg m-2 h-1) and a high photothermal efficiency (~92%) under one sun illumination (1 kW m-2), superior to most reported values. This high solar evaporation rate is attributed to the effective heat localization and adequate water supply in AMS, caused by the low bulk thermal conductivity, high porosity and hydrophilicity of AMS, as well as the set-up of a thermal insulator. The AMS is found to be highly efficient and stable, and it can be used to purify various types of waste water, including river water, seawater, and strong acid/alkaline water. Performance analysis of a large-scale prototype device based on the AMS design for field tests promises significant opportunities for highly-efficient, reusable, portable and low-cost water purification systems.
关键词： solar steam generator,anti-fouling,calcinated melamine sponge,fresh water production,scalable production
更新于2025-09-23 15:22:29
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Improving light yield measurements for low-yield scintillators
摘要： Light power spectra are introduced as a new tool for relative light yield (LY) determinations. Light event spectra have commonly been used for this purpose. Theoretical background supporting this change is provided. It is shown that the derivative of a light power spectrum can provide a reliable LY measurement at levels as low as 2% of those for high-yield liquid scintillators. Applications to light evolution in the PPO+LAB system and to water-based liquid scintillators are described.
关键词： light yield,data analysis,water-based scintillator,liquid scintillator
更新于2025-09-23 15:22:29
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Spectrophotometric determination of nitrate in hypersaline waters after optimization based on the Box-Behnken design
摘要： Monitoring dissolved nitrate (NO3?) concentrations is essential for conservation efforts in aquatic ecosystems. Spectrophotometric methods are a widely accepted approach for NO3? analysis. They detect NO3? as a colored diazo complex after reduction to nitrite (NO2?) and its consequent reaction with the so-called Griess reagent. This method is commonly used for freshwater and saline water samples, even though it requires applying a heavy metal in powder form (cadmium) or high concentrations of heavy metal salts (vanadium-III), as a reductant. There has been little discussion about applying these methods for hypersaline samples. This study optimizes an existing method for use in high saline conditions based on the Griess reaction. Five factors were studied: incubation temperature, reaction time, concentration of EDTA, concentration of trisodium citrate, and concentration of reductant (VCl3). Optimal conditions were obtained by using the Box-Behnken design and included using VCl3 17.5 mM, trisodium citrate 70 mM, and an incubation temperature of 60 °C for 40 min. These conditions provided a linear range from 0.55 μM to 50 μM NO3?. The method showed a moderate precision (ranging from 4.3% to 15.4%). The proposed protocol was tested with hypersaline natural samples and showed recovery rates between 92.6% and 100.1%. This protocol for NO3? determination is the first specifically described for hypersaline samples.
关键词： Hypersaline water,Nitrate analyses,Griess reaction,Vanadium chloride,Box-Behnken design
更新于2025-09-23 15:22:29