In this work, a nanocomposite containing gold (Au) nanofibers decorated iron-metal–organic framework (Fe-MOF) was successfully synthesized for electrochemical detection of acetaminophen (AAP). The as-synthesized Au@Fe-MOF nanocomposite was confirmed by various characterization techniques. Morphological analysis showed that the Au nanofibers with an average size of less than 10 nm were dispersed on the Fe-MOF. Cyclic voltammetric analysis showed that the Au@Fe-MOF nanocomposite showed well-defined redox peaks with higher current than that of GCE and Fe-MOF. The Au@Fe-MOF/ GCE exhibited a linear range, sensitivity, and detection limit of 0.5–18 μM, 4.95 μM/μA/cm2, and 0.12 μM, respectively. The Au@Fe-MOF/GCE showed a very low response for the interference materials. The real sample analysis revealed that the Au@Fe-MOF/GCE showed good recovery towards the AAP in urine and paracetamol. Therefore, the developed sensor can be used for quality control of AAP.
The presence of dyes in water is the most popular problem recently, so the current study was directed towards the synthesis of an effective material consisting of NiO and MWCNTs. The NiO/F-MWCNTs nanocomposite was synthesized using a simple hydrothermal method after functionalization of MWCNTs using sulfuric acid and nitric acid and utilized as an efficient surface to adsorption of malachite green dye from polluted water. The nanocomposite sample was characterized using several techniques are X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), Field emission scanning electron microscopy (FESEM), High- resolution transmission electron microscopy (HRTEM), Brunauer–Emmett–Teller (BET) surface area analysis, Barrett-Joyner-Halenda (BJH) analysis and Energy dispersive X-ray (EDX). The analytical results showed that the prepared nanocomposite is of good crystalline nature with a particle size of 25.43 nm. A significant specific surface area was 412.08 m2/ g which indicates the effective impact of the nanocomposite in the adsorption of malachite green (MG) dye. On the other hand, the effect of adsorbent dose, temperature, acidic function and contact time on the adsorption efficiency of dye was studied. The kinetics of dye adsorption were also investigated employing two kinetic models, pseudo-first-order model and pseudo-second-order model. Finally, the thermodynamic functions were determined to identify the type of the reaction and the spontaneity of the process.
Diamond-like nanocomposite (DLN) has become a promising thin film for many fields of applications due to its unique and tunable properties. However, low optical bandgap and thermal stability limits its application in many fields particularly as antireflection coating on solar cell. In the present study, the DLN thin film has been deposited using a mixed liquid precursor by rf-PECVD process. Surprisingly the presence of nc-C60 in FCC structure in DLN matrix has been observed. The degree of crystallinity and diameter of C60 have been increased significantly after annealed at 850 °C. The film has been annealed at 850 °C to primarily investigate its feasibility as antireflection coating (ARC) in compatible with industrial solar cell fabrication process. The refractive index and optical bandgap of the film were around 1.80 and 4.10 eV, respectively. Moreover, the optical bandgap has decreased to some extent to 3.92 eV even after annealing at such high temperature. The high SiOx at% and embedded nc-C60 enhanced the optical transparency and thermal stability of the DLN film. The solar-weighted average reflection of DLN-coated textured silicon was reduced significantly to 1.91%. The C60 embedded DLN film has a great potential to apply in different optoelectronic devices especially in solar cell as ARC.
In this investigation, Bi2MoO6 deposited graphene nanocomposite (BMG) was synthesized using a simple microwave assisted hydrothermal synthesis method. The synthesized BMG nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy with energy dispersive X-ray analysis, and photocurrent analysis. The study revealed that the catalysts prepared have high crystalline nature, enhanced light responsive property, high catalytic activity, and good stability. XRD results of BMG composite exhibit a koechlinite phase of Bi2MoO6. The surface property is shown by SEM and TEM, which confirmed a homogenous composition in the bulk particles of Bi2MoO6 and nanosheets of graphene. The catalytic behavior was investigated by the decomposition of Rhodamine B as a standard dye. The results exhibit excellent yields of product derivatives at mild conditions under ultrasonic/visible light-medium. Approximately 1.6-times-enhanced sono-photocatalytic activity was observed by introduction of Bi2MoO6 on graphene nanosheet compared with control sample P25 during 50 min test.
This work describes the facile synthesis of silver nanoparticle-decorated zinc oxide nanocomposite through a simple glycol reduction method. The silver nanoparticle-decorated zinc oxide nanocomposite-based pencil graphite electrode has been validated as a perceptive electrochemical sensing podium towards nitrite. The morphology of the prepared nanocomposite has been characterized via specific spectroscopic and electrochemical techniques. The sensor exhibits a notable enhancement in the cyclic voltammetric response to nitrite oxidation at an ideal peak potential of 0.76 V in pH 6.0 acetate buffer. Under optimum conditions of nitrite directly expanded with their concentration in the range from 30 to 1400 μM with a detection limit of 14 μM.
Herein, a series of g-C3N4 modified Bi2MoO6 nanocomposites using Bi2MoO6 and melamine as original materials are fabricated via sintering process. For presynthesis of Bi2MoO6 an ultrasonic-assisted hydrothermal technique is researched. The structure and composition of the nanocomposites are characterized by Raman spectroscopy, X-ray diffraction (XRD), and high-resolution field emission scanning electron microscopy (SEM). The improved photoelectrochemical properties are studied by photocurrent density, EIS, and amperometric i-t curve analysis. It is found that the structure of Bi2MoO6 nanoparticles remains intact, with good dispersion status. The as-prepared g-C3N4/Bi2MoO6 nanocomposites (BMC 5-9) are selected and investigated by SEM analysis, which inhibits special morphology consisting of Bi2MoO6 nanoparticles and some g-C3N4 nanosheets. The introduction of small sized g-C3N4 nanosheets in sample BMC 9 is effective to improve the charge separation and transfer efficiency, resulting in enhancing of the photoelectric behavior of Bi2MoO6. The improved photoelectronic behavior of g-C3N4/Bi2MoO6 may be attributed to enhanced charge separation efficiency, photocurrent stability, and fast electron transport pathways for some energy applications.
In recent years, special attention of energy researchers has been paid to application of polymer–carbon dots composite in energy storage systems. In this work, for the first time, we introduced a combination of polyaniline, carbon dots, polypyrrole and graphene as high performance supercapacitor. Synergistic effect of conductive polymers combined with specific properties of graphene and carbon dots improved the electrochemical performance of supercapacitor. Carbon dots was prepared from carrot juice hydrothermally as a biomass carbon source and polyaniline–carbon dots was synthesized via in-situ polymerization. Electrochemical performance of polyaniline with different carbon dots content was investigated and nanocomposite of polyaniline with 10 wt% carbon dots was selected to mix with polypyrrole–graphene to obtain a high potential window supercapacitor. The as-prepared composite was characterized by several spectroscopic and microscopic techniques. The electrochemical properties of this electrode were studied by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy techniques. A polyaniline–carbon dots (10%)/polypyrrole–graphene has showed the maximum specific capacitance of 396 F g− 1. Value of specific capacity remained at 62% under the current density of 5 A g− 1.
Here, Zn ferrite is synthesized along with reduced graphene oxide (rGO) by a facile one-step hydrothermal method. The difference between the synthesized nanocomposites with those in other reported work is that the reaction conditions in this work are 160 oC for 12 h. The synthesized products are characterized by field-emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and attenuated total reflection. Further, the adsorption property of rGO–Zn ferrite (rGZF) nanocomposite is studied after confirming its successful synthesis. The adsorption capacity of rGZFs toward rhodamine B (RB) is ˃ 9.3 mg/g, whereas that of bare ZF nanoparticles is 1.8 mg/g in aqueous media. The efficiencies of rGZF and bare ZF to remove RB are 99 % and 20 %, respectively. Employing rGZF, 60 % of RB is decomposed within 5 min. The kinetic study reveals that the adsorption process of removing RB by bare Zn ferrite follows pseudo-firstorder kinetics. However, after zinc ferrite is incorporated with rGO, the kinetics changes to pseudo-second-order. Furthermore, the Langmuir isotherm is accomplished by the adsorption process employing rGZF, indicating that a monolayer adsorption process occurs. The thermodynamic parameters of the process are also calculated.
나노여과를위한 박막 나노복합체(TFN) 멤브레인 기술의 발전은 천연 자원에서 오염 물질을 제거하는 데 중요하 다. 최근에는 기존의 박막 복합체(TFC) 및 나노복합체 멤브레인에서 불가피한 단점을 극복하기 위해 다양한 금속유기구조체 (MOF) 수정이 테스트되었다. 일반적으로 MIL-101(Cr), UiO-66, ZIF-8 및 HKUST-1 [Cu3(BCT2)]은 용매 투과성 및 용질 제 거 측면에서 막 성능을 현저하게 향상시키는 것으로 입증되었다. 이 리뷰에서는 이러한 MOF가 나노 여과에 미치는 영향에 대 한 최근 연구가 논의될 것이다. 서로 다른 금속유기구조체의 동시 사용 및 고유한 금속유기구조체 레이어링 기술(예: 딥 코팅, 스프레이 사전 배치, Langmuir-Schaefer 필름 등)과 같은 다른 새로운 기능도 멤브레인 성능을 향상시켰다. 이러한 MOF 변 형 TFN 멤브레인은 각각의 TFC 및 TFN 멤브레인에서 분리 성능을 향상시키는 것으로 자주 나타났을 뿐만 아니라 많은 보 고서에서 비용 효율적이고 환경 친화적인 공정에 대한 잠재력을 설명한다.
A facile microwave assisted solvothermal process is designed for fabricating SnS nanoparticles decorated on graphene nanosheet, which used as visible light driven photocatalyst. Some typical characterization techniques such as XRD, FT-IR, SEM with EDX analysis, and TEM and BET analysis are used to analyse the physical characteristics of as-prepared samples. Spherical SnS nanoparticles are uniformly dispersed on the surface of graphene nanosheet due to ammonia, which can prevent the aggregation of graphene oxide. Meanwhile, microwave radiation provides fast energy that promotes the formation of spherical SnS nanoparticles within a short time. The visible light photocatalytic activity of as-prepared SnS-GR nanocomposites is analysed through photodegradation efficiency of methylene blue with high concentration. According to the higher photocatalytic property, the as-prepared SnS-GR nanocomposites can be expected to be an efficient visible light driven photocatalyst. After five cycles for decolorization, the rate decreases from 87 % to 78 % (about 9 %). It is obvious that the photocatalytic activity of SnS-GR nanocomposite has good repeatability.