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Photocatalytic decontamination of phenol and petrochemical wastewater through ZnO/TiO <sub/>2</sub> decorated on reduced graphene oxide nanocomposite: influential operating factors, mechanism, and electrical energy consumption
摘要： ZnO/TiO2 anchored on a reduced graphene oxide (rGO) ternary nanocomposite heterojunction was synthesized via the multi-step method including hydrothermal, solvothermal and sol–gel methods. XRD, Raman, FESEM, EDX, Dot Mapping EDS, BET, FTIR, UV-VIS, TGA, and EIS techniques were utilized for characterizing as-synthesized catalysts. The XRD and Raman data proved the formation of anatase phase TiO2 and wurtzite phase ZnO in the prepared samples. Further, the UV-Vis spectrum confirmed that the band gap value of ZnO/TiO2 diminished on introduction of graphene oxide. Photocatalytic performance of the fabricated catalysts was investigated by decontamination of phenol in aqueous solutions. The effect of different operational factors such as pH, catalyst dosage, phenol concentration, and light illumination was investigated to find the optimum decontamination conditions. According to the results, complete degradation of phenol was achieved at pH = 4, catalyst dosage of 0.6 g L?1, light intensity of 150 W, and phenol initial concentration of 60 ppm at 160 min under visible light illumination. With the addition of graphene oxide to the composite, a significant increase was detected in the photocatalytic performance due to the higher available surface area and lower electron/hole recombination rate. In addition, the scavenging experiments revealed that the ?OH is responsible for the degradation of phenol during the reaction. The degradation mechanism, economic performance, mineralization, and recyclability were also investigated. Kinetic studies confirmed that photocatalytic degradation process followed the pseudo-first-order kinetic model. A case of real wastewater treatment was used to examine the performance of the catalyst for real case studies.
关键词： Phenol degradation,Nanocomposite,Wastewater treatment,Photocatalysis,ZnO/TiO2,Reduced graphene oxide
更新于2025-09-19 17:15:36
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Preparation and characterization of bismuth oxychloride/reduced graphene oxide for photocatalytic degradation of rhodamine B under white-light light-emitting-diode and sunlight irradiation
摘要： Facile and template-free two-step synthesis of bismuth oxychloride/graphene oxide (BiOCl/GO) and bismuth oxychloride/reduced graphene oxide (BiOCl/rGO) photocatalysts for degradation of rhodamine B (RhB) under low-power white light–emitting diode (wLED) irradiation (1.6 W/cm2) and sunlight is demonstrated. These photocatalysts were characterized by transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectrometry, X-ray di?raction, and micro-Raman, Fourier-transform infrared, X-ray photoelectron, and UV–Vis di?use re?ectance spectroscopy. Under wLED irradiation, the prepared BiOCl/rGO photocatalysts exhibited excellent photodegradation activity toward RhB through chromophore cleavage mechanism and toward phenol in the presence of RhB with notable dye-sensitized e?ect. Through scavenging experiments, superoxide radicals were notably involved in RhB degradation. With the highest charge separation e?ciency and lowest recombination rate, the photocatalytic activity of BiOCl/rGO reached a maximum rate constant of 0.1899 min?1, 2.0 and 3.0 times higher than those of BiOCl/GO and BiOCl, respectively. In the stability study, only a slight loss (4.5%) in photodegradation was observed after BiOCl/rGO was used in ?ve cycles of photodegradation runs. Compared with commonly used photocatalyst such as TiO2 (P25), BiOCl/rGO demonstrated superior photocatalytic activity and stability under wLED irradiation for various dyestu?s (rhodamine 6 G, methylene blue, and fast green FCF) in di?erent environmental water samples (lake, pond, and sea water).
关键词： wLED-induced photodegradation,Rhodamine B,Reduced graphene oxide,Phenol,Sunlight irradiation,Bismuth oxychloride
更新于2025-09-19 17:15:36
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Thermally-stable low-loss polymer dielectrics enabled by attaching crosslinkable antioxidant to polypropylene
摘要： Polymer dielectrics with low loss and high-temperature tolerance are extremely desirable as electrical energy storage materials for advanced electronics and electrical power applications. They can allow fast switching rates during power conversion and therefore achieve high power densities without thermal issues. Here we explore polypropylene (PP), the state of the art dielectric polymer, and present an innovative approach to substantially improve the thermal stability and concurrently reduce the dielectric loss of PP. In particular, crosslinkable antioxidant groups, hindered phenol (HP), are incorporated into PP via well-controlled chemical synthesis. The grafted HP can simultaneously serve as radical scavenger and crosslinker, thereby constraining thermally decomposed radicals and charge transport in the synthesized PP-HP copolymer. As a result, the upper-temperature limit of PP-HP is greatly extended to 190 ?C and the electrical loss is even gradually reduced upon thermal annealing. The copolymer after heating under 190 ?C exhibits better dielectric properties than the PP without any thermal treatment. The experimental results indicate that the PP-HP copolymers are promising materials for high temperature, low loss, and high voltage dielectric applications.
关键词： energy storage,crosslinking,hindered phenol antioxidants,functionalized polypropylene,high-temperature low-loss dielectrics,electrical leakage current
更新于2025-09-19 17:13:59
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Efficient Wastewater Remediation Enabled by Self-Assembled Perovskite Oxide Heterostructures with Multiple Reaction Pathways
摘要： Advanced oxidation processes (AOPs) are promising for the removal of retardant organic pollutants in water. However, traditional free-radicals-dominated AOPs are often limited by poor tolerance to water characteristics. Recently, creating nonradical processes has been considered as an effective strategy to overcome this limitation, while the function and mechanism of nonradical processes are still unclear in the important oxides catalytic systems. Herein, the nonradical-dominated peroxymonosulfate (PMS)-based AOPs are triggered on a heterostructural perovskite nanocomposite catalyst (La0.4Sr1.05MnO4?δ), which is constructed from single and Ruddlesden?Popper perovskite phases by a facile self-assembled synthesis method. Noticeably, the phenol degradation rate of the heterostructural nanocomposite oxide is ～2 times that of its individual components. This activity enhancement can be attributed to the abundant active oxygen vacancies, strong affinity to the reactants, and high-electron-transfer efficiency in the unique heterointerface of the nanocomposite. Furthermore, a ternary mechanism is unveiled: contaminants are oxidized not only by the function of radicals and singlet oxygen evoked from the active sites of perovskites but also by the transfer of their electrons to PMS via the beneficial surface of a heterostructral catalyst. This study provides new insights into nonradical-based AOPs derived from hybrid metal oxides in a PMS system.
关键词： Nonradical-based AOPs,Peroxymonosulfate activation,Phenol degradation,Electron-transfer pathways,Perovskite nanocomposites
更新于2025-09-19 17:13:59
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Macroscopically oriented (3-pentadecyl phenol) dangled fluorene based conductive polymer through side chain engineering for microelectronics
摘要： In this paper, we have designed a solution processable macroscopically oriented conductive polymer of fluorene dangled 3-pentadecylphenol (Polyfluorene pentadecyl benzene, PFLPDB) through side chain engineering and self-assembly approach. Initially fluorene was coupled with 3-pentadecylphenol (3-PDP) and further subjected to oxidative polymerisation in the presence of anhydrous ferric chloride (FeCl3). Effects of polarity of the solvent and time on self-assembly process was studied using various microscopic techniques which suggested the formation of macroscopically oriented fibers having 20–30 nanometer diameter in chloroform with an electrical conductivity of (2.1·10–2 S·cm–1). Optical and electrochemical band gaps were calculated from the studies made by UV-Vis spectroscopy and cyclic voltammetry. Its field effect transfer characteristics were further studied by fabricating an Organic field effect transistor (OFET) device having configuration (Si/SiO2/PFLPDB/Ag) and measured its field effect mobility (1.076 cm2·v–1·s–1) at 1 V and ON/OFF ratio of the device calculated as 1.82·103 suggests its application as an excellent active material for organic microelectronics.
关键词： molecular engineering,macroscopically ordered,3-pentadecyl phenol dangled fluorene,OFET,polymer synthesis
更新于2025-09-16 10:30:52
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Enhanced photocatalytic activity of ZnO sensitized by carbon quantum dots and application in phenol wastewater
摘要： This work reports on preparation of ZnO composites sensitized by carbon quantum dots (CQDs) and its photocatalytic degradation on phenol under visible-light illumination. With the help of tools such as transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS), UV–vis diffusive reflectance spectra (UV–Vis DRS) and gas chromatograph-mass spectrometer (GC-MS), successful synthesis of ZnO composites sensitized by CQDs has been confirmed, which extend the spectral response range of the procatalyst to the visible region enhancing the utilization of sunlight. Meanwhile, transient photocurrent response and Nyquist plot analysis were further proved the increase in carrier separation efficiency of the procatalyst. The photocatalytic ability of the composites was measured by XPA-7 photocatalytic instrument with using phenol as simulate pollutants. And the photocatalytic reaction mechanism was also revealed by the Mott-Schottky plot, band structure and trapping experiments of active species. The results exhibit that the photocatalytic performance of ZnO composites sensitized by CQDs is 60% higher than that of pure ZnO with good stability and reusability, whose utilization has almost no significant change after 10 cycles.
关键词： ZnO,Phenol,Photocatalysis,L-CQDs,Composites
更新于2025-09-16 10:30:52
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Photocatalytic producing dihydroxybenzenes from phenol enabled by gathering oxygen vacancies in ultrathin porous ZnO nanosheets
摘要： As an energy-efficient and environmental friendliness method, solar sunlight-driven photo-oxidation catalysis process for organic chemicals synthesis has gained enormous attention, but still faces huge challenge in developing highly-efficient photocatalysts material. Two-dimensional materials engineering and surface defect engineering of photocatalysts both provide an effective strategy to improve the catalytic activity. Inspired by these pathway, we design and synthesize ultrathin porous ZnO nanosheets featuring abundant oxygen vacancies specific to producing dihydroxybenzenes based on a photocatalytic oxidation process. Several valid characterizations had been employed to discern the structural character of the obtained model catalyst, revealing that the resultant ZnO sheets afford an average thickness of 3 nm, and abundant surface porosity, thereby contributing to the rich oxygen vacancies. Such a structure could generate a synergistic effect to enhance the optical absorption and improve the transportation rate of photogenerated charge carriers from the materials design. As expected, the specific ultrathin ZnO nanosheets exhibited a greatly-improved photocatalytic activity for oxidation of phenol to dihydroxybenzenes (31.5% conversion & almost 76.7% selectivity of DHB), near 3 and 4 times higher, respectively than its counterparts that one with few oxygen vacancies and Bulk-ZnO. Impressively, the obtained catalyst showed durable catalytic activity without any activity loss during the five recycling. Finally, the feasible oxidation mechanism was proposed and testified by the controlled scavenger experiments. This study provides a novel reference on how to design high-performance photocatalytic material.
关键词： oxygen vacancies,ZnO,ultrathin nanosheets,oxidation of phenol,photocatalytic
更新于2025-09-12 10:27:22
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Induced Circular Dichroism of Jet-Cooled Phenol Complexes with <i>R</i> -(–)-2-Butanol
摘要： The induced circular dichroism (ICD) of phenol complexed with R-(–)-2-butanol (PhOH-(–)BOH) in a supersonic jet is investigated using resonant two-photon ionization CD (R2PICD) spectroscopy. The R2PICD spectrum of PhOH-(–)BOH exhibits nonzero ICD bands near the absorption region of bare PhOH, where (–)BOH is transparent. Two different conformers containing a single hydrogen bond between PhOH and (–)BOH are identified using ultraviolet(UV)-UV hole-burning and infrared (IR) ion-dip spectroscopy combined with quantum theoretical calculations. The ICD values of the two conformers are similar to each other. To understand these similar ICD effects of the conformers, the geometrical asymmetry of the PhOH moiety bound to (–)BOH and the coupling strength of the electric transition dipole moments between PhOH and (–)BOH are estimated. Comparing the ICD values of PhOH-(–)BOH with those of PhOH-(–)-L-methyl lactate in the previous report (Hong, A.; Moon, C. J.; Jang, H.; Min, A.; Choi, M. Y.; Heo, J.; Kim, N. J. J. Phys. Chem. Lett. 2018, 9, 476-480), we investigate the physical properties that may govern the differences of the ICD values between the two complexes.
关键词： R-(–)-2-Butanol,Phenol Complexes,Supersonic Jet,Resonant Two-Photon Ionization CD Spectroscopy,Induced Circular Dichroism
更新于2025-09-12 10:27:22
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Facile constructing plasmonic Z-scheme Au NPs/g-C3N4/BiOBr for enhanced visible light photocatalytic activity
摘要： A novel ternary Au NPs/g-C3N4/BiOBr Z-scheme heterojunction composite was fabricated through hydrothermal and in-situ reduction method, and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, ultraviolet-visible diffuse reflection spectroscopy and photoluminescence emission spectroscopy. The photocatalytic activity was evaluated by the degradation of phenol under visible-light irradiation. It was found that Au NPs/g-C3N4/BiOBr showed enhanced photocatalytic activity, which is 3-fold higher than g-C3N4 and 2.5-fold higher than BiOBr. This could be attributed to the effective separation of photogenerated electron-hole pairs, narrowed band gap (2.10 eV) and surface plasmon resonance (SPR).
关键词： Au NPs/g-C3N4/BiOBr,Z-scheme,phenol,visible-light photocatlysis,plasmon
更新于2025-09-12 10:27:22
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Controlled synthesis of reduced graphene oxide supported magnetically separable Fe3O4@rGO@AgI ternary nanocomposite for enhanced photocatalytic degradation of phenol
摘要： A ternary nanocomposite of Fe3O4@rGO@AgI was successfully synthesized by re?ux method for photodegradation of phenol. The prepared nanocomposite was characterized for the physicochemical properties through XRD, FESEM, TEM, TGA, FTIR, and PL spectroscopy techniques. Fe3O4@rGO@AgI exhibited higher photo-catalytic performance of 99% phenol degradation compared to 62, 75 and 78% using Fe3O4, Fe3O4@rGO and Fe3O4@AgI nanocomposites, respectively. The superior photocatalytic performance was mainly attributed to the rapid transportation of photogenerated electrons from GO nanosheets to AgI. The addition of H2O2 has further enhanced the phenol degradation and was the optimized loading amount of 0.4 g/350 mL achieved the highest degradation ef?ciency. The ?ndings revealed that basic conditions, initial phenol concentration and catalyst amounts have signi?cant in?uence on the photocatalyst performance. The 81% recyclability after ?ve continuous cycles implied the excellent stability of the photocatalyst for practical applications.
关键词： APTES and TEOS,Graphene oxide,Re?ux method,Plasmon resonance effect,Fe3O4@rGO@AgI,Phenol
更新于2025-09-12 10:27:22