- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
The Analysis of Starlight (Two Centuries of Astronomical Spectroscopy) || The analysis of sunlight: the earliest pioneers
摘要： The story of solar, and hence also of astronomical spectroscopy, began in 1666 when the young Isaac Newton (1642–1726) wrote these famous words: I procured me a Triangular glass-Prisme, to try therewith the celebrated Phaenomena of Colours. And in order having darkened my chamber, and made a small hole in my window-shuts, to let in a convenient quantity of the Suns light, I placed my Prisme at his entrance, that it might thereby be refracted to the opposite wall. [1]
关键词： sunlight,solar spectrum,spectroscopy,Isaac Newton,prism
更新于2025-09-10 09:29:36
-
Photoactive Brownmillerite Multiferroic KBiFe <sub/>2</sub> O <sub/>5</sub> and Its Potential Application in Sunlight-Driven Photocatalysis
摘要： KBiFe2O5 (KBFO) is an upcoming promising brownmillerite-structured multiferroic photoactive material for next-generation photovoltaic and photocatalytic applications. In the present work, KBFO has been developed using multistep thermal treatment method to reduce the volatility of constituent elements and improve the stability of compound. The band gap of KBFO (found to be ～1.68 eV) extends to the near-infrared region compared to traditional perovskite-structured multiferroics. The magnetic and dielectric transitions occur in the same temperature range (740 K?800 K), re?ecting the existence of magneto-dielectric e?ect in the as-synthesized sample. It also shows promising photocatalytic activity by degrading organic e?uents under natural sunlight compared to regular perovskite BiFeO3 photocatalyst (operating under visible light). A new application of brownmillerite multiferroic KBFO photocatalyst in environmental and energy applications has been explored by integrating the structural, optical, magnetic, and dielectric properties of the same.
关键词： KBiFe2O5,photocatalysis,brownmillerite,sunlight-driven,multiferroic
更新于2025-09-10 09:29:36
-
Sunlight Assisted Photocatalytic Degradation of Ciprofloxacin in Water Using Fe Doped ZnO Nanoparticles for Potential Public Health Applications
摘要： Antibiotic residues in the aquatic environment have the potential to induce resistance in environmental bacteria, which ultimately might get transferred to pathogens making treatment of diseases difficult and poses a serious threat to public health. If antibiotic residues in the environment could be eliminated or reduced, it could contribute to minimizing antibiotic resistance. Towards this objective, water containing ciprofloxacin was treated by sunlight-assisted photocatalysis using Fe-doped ZnO nanoparticles for assessing the degradation potential of this system. Parameters like pH, temperature, catalytic dosage were assessed for the optimum performance of the system. To evaluate degradation of ciprofloxacin, both spectrophotometric as well as microbiological (loss of antibiotic activity) methods were employed. 100 mg/L Fe-doped ZnO nanoparticle catalyst and sunlight intensity of 120,000–135,000 lux system gave optimum performance at pH 9 at 30 °C and 40 °C. Under these conditions spectrophotometric analysis showed complete degradation of ciprofloxacin (10 mg/L) at 210 min. Microbiological studies showed loss of antibacterial activity of the photocatalytically treated ciprofloxacin-containing water against Staphylococcus aureus (108 CFU) in 60 min and for Escherichia coli (108 CFU) in 75 min. The developed system, thus possess a potential for treatment of antibiotic contaminated waters for eliminating/reducing antibiotic residues from environment.
关键词： antibiotic residues,ciprofloxacin,Fe-doped ZnO nanoparticles,aquatic environment,sunlight,photocatalysis
更新于2025-09-10 09:29:36
-
Enhanced photocatalytic performance of sphere-like AgCl/ rGO catalysts under simulated and natural sunlight irradiation
摘要： Here we prepared sphere-like AgCl by stirring in the presence of sodium oleate, and loaded it on the surface of reduced graphene oxide (rGO) to form sphere-like AgCl/ rGO composite. Sphere-like AgCl exhibited enhanced degradation e?ciency after the inserting of rGO with degrading 80.6% of tetracycline (TC) within 90 min, which was about 15.4% higher than pristine spherical AgCl (65.2%) under simulated sunlight irradiation. Moreover, ?ve times cycling test of the obtained samples had revealed the improved stability of AgCl/ rGO. The remarkable photocatalytic activity was mainly due to the better interaction between AgCl and rGO, where charge separation and transfer as well as the utilization of sunlight were boosted. Improved photocatalytic stability was majorly ascribed to the fast electrons transfer from AgCl to rGO before the reduction of Ag+ to Ag. Besides, a possible photocatalytic reaction mechanism under simulated sunlight was proposed. Meanwhile, AgCl/ rGO also exhibited better photocatalytic e?ciency for the degradation of TC under natural sunlight irradiation (73.2%), which is hopeful for practical application of photocatalysts.
关键词： Natural sunlight irradiation,Sphere-like AgCl/ rGO,Tetracycline,Photocatalyst
更新于2025-09-09 09:28:46
-
Transformation of Commercial TiO <sub/>2</sub> into Anatase with Improved Activity of Fe, Cu and Cu–Fe Oxides Loaded TiO <sub/>2</sub>
摘要： In the present study copper and iron oxides loaded TiO2 catalysts are prepared by the deposition-precipitation method (DP) and the photocatalytic efficiency of these catalysts are tested for the degradation of Rose Bengal dye (Acid Red 94) under sunlight. The catalysts are characterized by XRD, TEM and UV-vis diffuse reflectance spectral analysis. It is interesting to note that the rutile form of commercial TiO2 is competently converted into anatase after loading oxides of Cu, Fe and Cu–Fe on TiO2 as evident from XRD analysis. This result is consistence with the result obtained in UV-vis diffuse reflectance spectra. TEM analysis confirms the nano particles of Cu and Fe deposited on TiO2. Photocatalytic studies were performed in a batch reactor under solar radiation. Preliminary studies are performed to understand the photocatalytic degradability of the dye and optimization of catalyst weight and dye concentration. Kinetic studies were done at different dye concentrations and it was found that the rate equation followed first order kinetics and obeyed Langmuir–Hinshelwood model. The comparison of the activity of blank TiO2, copper or/and iron oxides loaded TiO2 catalysts showed that the Cu and Fe oxide loaded catalysts are more active than pure TiO2 and also the Cu–Fe oxides co-loaded TiO2 catalysts showed much best activity. The order of activity of the catalysts is in the following order: Cu–Fe/TiO2 > Cu/TiO2 > Fe/TiO2 > TiO2. The enhanced activity of metal oxide loaded TiO2 is attributed to the presence of TiO2 in anatase form after loading, which enhanced the charge transfer from the TiO2 to adsorbed molecules for reaction.
关键词： Sunlight,TiO2,Rutile into Anatase,Photocatalyisis,Cu/Fe Loading,Rose Bengal Dye
更新于2025-09-09 09:28:46
-
Application of a photostable silver-assisted Z-scheme NiTiO3 nanorod/g-C3N4 nanocomposite for efficient hydrogen generation
摘要： The performance and reaction mechanism of a silver (Ag)-assisted one-dimensional NiTiO3 nanorod/CN heterostructure nanocomposite (NTACN) photocatalyst for hydrogen (H2) production were explored with simulated sunlight. The physicochemical properties of the synthesized catalysts were examined using various spectrophotometers. The newly developed NTACN samples displayed an enhanced photocatalytic activity in producing hydrogen. Specifically, the H2 production rate of NTACN-5 (with a NT-to-ACN weight ratio of 5) was 3351 mmol/g-h, which was 1.42 times higher than that of ACN-4 with a Ag-to-CN ratio of 4 (2325 mmol/g-h). The effects of the Ag-to-CN and NiTiO3-to-ACN ratios on the photocatalytic activity of NTACN photocatalysts were determined. The NTACN photocatalysts exhibited a high long-term photostability under simulated sunlight irradiation. The increased photocatalyst performance and photostability were primarily ascribed to an improved charge separation efficiency due to a Z-scheme reaction mechanism as well as the assistance provided by Ag as a charge transfer shuttle and in the surface plasmon resonance effect. A photocatalytic mechanism for hydrogen generation over the NTACN photocatalysts under simulated sunlight irradiation is suggested.
关键词： Photostability,Simulated sunlight,One dimension,Z-Scheme mechanism,Charge transfer shuttle
更新于2025-09-09 09:28:46
-
A Cross‐linked Conjugated Polymer Photosensitizer Enables Efficient Sunlight‐induced Photooxidation
摘要： Photooxidation under sunlight has great potentials in organic synthesis, bacterial killing, organic waste treatment, etc. Photosensitizers (PSs) often play a very important role in this process. High 1O2 generation efficiency and excellent photostability under sunlight, as well as easy recyclability are ideal properties for PSs used for photooxidation, which are not easy to achieve simultaneously. Herein, a pure organic porous conjugated polymer PS of CPTF was designed and synthesized to show great photostability, large specific surface area and high 1O2 generation efficiency under sunlight for photooxidation in different applications. Taking the oxidation of aromatic aldehyde to aromatic acid as an example, the PS catalyst shows excellent recyclability, which enables solvent-free reactions in high yields both under direct sunlight and simulated AM1.5G irradiation. In addition, the successful application of CPTF in bacterial killing and organic waste decomposition under simulated AM1.5G irradiation indicates the potential of CPTF in sunlight-induced waste water treatment.
关键词： singlet oxygen,sunlight-induced organic synthesis,photooxidation,photosensitizers,sunlight-induced wastewater treatment
更新于2025-09-04 15:30:14
-
A Cross-linked Conjugated Polymer Photosensitizer Enables Efficient Sunlight-induced Photooxidation
摘要： Photooxidation under sunlight has great potentials in organic synthesis, bacterial killing, organic waste treatment, etc. Photosensitizers (PSs) often play a very important role in this process. High 1O2 generation efficiency and excellent photostability under sunlight, as well as easy recyclability are ideal properties for PSs used for photooxidation, which are not easy to achieve simultaneously. Herein, a pure organic porous conjugated polymer PS of CPTF was designed and synthesized to show great photostability, large specific surface area and high 1O2 generation efficiency under sunlight for photooxidation in different applications. Taking the oxidation of aromatic aldehyde to aromatic acid as an example, the PS catalyst shows excellent recyclability, which enables solvent-free reactions in high yields both under direct sunlight and simulated AM1.5G irradiation. In addition, the successful application of CPTF in bacterial killing and organic waste decomposition under simulated AM1.5G irradiation indicates the potential of CPTF in sunlight-induced waste water treatment.
关键词： photooxidation,singlet oxygen,photosensitizers,sunlight-induced organic synthesis,sunlight-induced wastewater treatment
更新于2025-09-04 15:30:14
-
Effect of temperature on structural and optical properties of solvothermal assisted CdS nanowires with enhanced photocatalytic degradation under natural sunlight irradiation
摘要： Photocatalytic degradation of toxic dyes is an important topic across the globe. This paper reports the photocatalytic degradation of methylene blue (MB) dye using cadmium sulfide (CdS) nanowires as a photocatalyst under natural sunlight irradiation. The CdS nanowires were successfully synthesized by a solvothermal route using ethylenediamine as a solvent with a series of different reaction temperature from 160 to 200 °C for a fixed time of 24 h. Multiple characterization techniques were used to investigate the structural, morphology, optical and photocatalytic study of as-synthesized CdS samples. The XRD patterns reveal highly crystalline CdS nanomaterials with a hexagonal crystal structure. The FESEM and HRTEM observations clearly confirmed a large number of uniform nanowires grown in different directions and interconnected with each other. The stoichiometric ratio of Cd:S is almost 1:1, confirmed by EDS analysis. Room temperature PL spectra of CdS nanowires exhibit a narrow emission at a wavelength of 512 nm. The CdS nanowires synthesized at 200 °C shows the excellent photocatalytic performance with highest photodegradation efficiency has reached up to 98.75% within 20 min, under sunlight irradiation. The 93.06% and 89.10% photodegradation efficiency were observed in CdS nanowires synthesized at 180 °C and 160 °C, respectively. From these result, it is observed that the crystallite size and morphology of CdS nanowires are the influence factors for the photodegradation efficiency of MB dye. Furthermore, the mechanism of MB dye photodegradation using CdS nanowires was discussed. These CdS nanowires with high photocatalytic activity can be used for future in water pollutant degradation.
关键词： Hexagonal CdS,Solvothermal synthesis,MB dye degradation,Reaction temperature,Sunlight irradiation
更新于2025-09-04 15:30:14
-
Manganese phosphinocarbodithioate for RAFT polymerisation with sunlight-induced chain end post-treatment
摘要： A new manganese RAFT agent of the formula Cp(CO)2MnP(Ph)2C(vS)SCH(CH3)Ph was synthesized in a good overall yield by a three-step reaction from cymantrene and diphenylphosphine as the main starting materials. This complex proved to be e?cient for the control of RAFT polymerisation of St, n-BA and DMAAm. The reaction course could be conveniently monitored by 31P NMR spectroscopy. The controlled character of these polymerisations and the integrity of the polymer chain ends were demonstrated by the synthesis of diblock copolymers of St and n-BA. In the case of long polymerisation times (i.e. for PSt), photo-induced polymer chain coupling reactions were detected. Importantly, removal of the Mn-RAFT-ω-chain end by visible light irradiation led to the formation of a monomodal SH-terminated PSt. These phenomena were evidenced by IR spectroscopy, SEC with RI and UV detection modes and by ESI mass spectrometry.
关键词： sunlight-induced chain end post-treatment,visible light irradiation,manganese phosphinocarbodithioate,RAFT polymerisation,diblock copolymers
更新于2025-09-04 15:30:14