CsxWO3 nanorods coated with polyelectrolyte multilayers are developed as “four‐in‐one” multifunctional nanomaterials with significant potential for computed tomography/photoacoustic tomography ...bimodal imaging‐guided photothermal/photodynamic cancer treatment.
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•The tree-branch-like Fe2P@NixP/NF nanoarrays architecture was constructed.•Simultaneousenhancementoftheelectronandmasstransportcanberealized.•The Fe2P@NixP/NF electrode exhibits ...superior electrocatalytic HER and UOR activity.
It’s highly desirable but still challenging, through the structure construction strategy, to design brilliant bifunctional electrocatalysts for the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) with both fast electron and mass transport, especially under high current densities. Herein, a novel tree-branch-like Fe2P@NixP heterostructure nanoarrays on NF (denoted as Fe2P@NixP/NF) were fabricated as bifunctional catalysts to realize urea-rich-water electrolysis at large current density. Benefiting from the tree-branch-like hierarchical architectures with rich exposed heterointerfaces between Fe2P and NixP that can simultaneously achieve facilitated mass and electron transfer, the elaborated Fe2P@NixP/NF electrode shows brilliant electrocatalytic UOR and HER performance. The assembled Fe2P@NixP/NF|| Fe2P@NixP/NF couple could yield the current density of as high as 500 mA cm−2 at super low cell voltage of 1.604 V for urea electrolysis. We believe our work can chart a brand-new-path in developing an industrial electrolyzer to promise an energy-saving H2 generation along with urea-rich wastewater treatment.
This paper reports the synthesis and characterization of an efficient sunlight active photocatalyst, i.e. α-Bi2O3 nanorods for the photocatalytic degradation of Rhodamine B and 2,4,6-trichlorophenol. ...The α-Bi2O3 nanorods were synthesized by a simple surfactant free sono-chemical route at ambient conditions and characterized in detail in terms of their morphological, structural, compositional and optical properties. The detailed characterizations revealed that the prepared nanorods exhibited high purity, well-crystalline monoclinic α-Bi2O3 structure and excellent optical properties. The catalytic behaviour of α-Bi2O3 was investigated for the degradation of a cationic dye (Rhodamine B), its simulated dye bath effluent and 2,4,6-trichlorophenol under solar light irradiation. The as-synthesized α-Bi2O3 nanorods catalyst exhibited excellent solar-light driven photocatalysis towards Rhodamine B (97% dye degradation in 45min) and 2,4,6-trichlorophenol (88% dye degradation in 180min). The presented results demonstrate that α-Bi2O3 nanorods are excellent solar-light driven photocatalyst for the photocatalyst degradation of organic dyes and pollutants.
ZnO nanorods (NRs) are promising components in a wide range of nanoscale devices for future applications in photocatalysis, solar cells, optical devices and biochemical sensing. The nanorods in the ...form of arrays vertically oriented to the substrate may be obtained by electrochemical deposition but morphology of the film is very sensitive to the synthesis conditions. This article provides a comprehensive review on various electrosynthesis procedures developed to obtain the nanorods of desired structure, diameter, density on the substrate.
We discuss the growth mechanisms and influence of different parameters such as the type and concentration of Zn2+ and OH− precursors, the value of applied potential or current density on the morphology of obtained ZnO films and the role of various structural modifiers on the shape of ZnO nanostructures. We present a brief analysis of the influence of electrosynthesis conditions and postannealing of the samples on optical and electrical properties of ZnO nanowires deposited on the conducting substrate. A short summary of the practical applications of ZnO nanorods is also provided.
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•Successfully synthesized Fe3O4 nanorods coated PPy/rGO by chemical reflux method.•Fe3O4@PPy/rGO/GCE effectively sensing dopamine molecules.•Fe3O4@PPy/rGO/GCE shows better ...repeatability, reproducibility and stability.•Photocatalytic studies reveal 84% ACP degradation by Fe3O4@PPy/rGO with persulfate.•ACP photodegradation studies shows rate constant of 9.13 × 10−4 M−1 s−1.
The increase in the world’s population has exerted tremendous pressure on the research community to solve the related health and environmental issues. Hence, it is an important and challenging task to design a multifunctional catalyst that both aids medical diagnostics and removes organic pollutants from aqueous environments. Herein, we developed iron oxide nanorods uniformly coated on the polypyrrole/reduced graphene oxide (Fe3O4@PPy/rGO) nanohybrids by the chemical reflux method. The optimized Fe3O4@PPy/rGO nanohybrids show better electrochemical detection of dopamine (DA) with a low detection limit (0.063 µM) and a better linearity range (0 to 100 µM), with a coefficient of determination of 0.994. The Fe3O4@PPy/rGO nanohybrids reveal an excellent DA recovery rate of 97– 98% during real sample analysis. In addition, photocatalytic studies reveal that 84% acetaminophen (ACP) degradation by Fe3O4@PPy/rGO nanohybrids was noticed with the persulfate. The effect of co-existing photocatalytic studies affirms that the higher ACP photodegradation rate constant of 9.13 × 10−4 M−1 s−1 was obtained in the presence of the Cl− ion. The present work provides a new pathway for the development of a metal oxide with a conducting polymer and graphene-based catalyst for multi-functional applications for the electrochemical sensing and photodegradation of organic pollutants.
The monoclinic VO2(M) has promising applications in intelligent devices but its preparation still requires improvement to permit cost-effective mass production. In this work, we report a 2-stage ...approach for producing VO2(M) nanorods by (1) hydrothermal reduction of vanadium pentoxide by sodium bisulfate at 220 °C to form VO2(A), and (2) subsequent thermal activated phase transformation of VO2(A) to VO2(M) at 350–450 °C in vacuum. The obtained VO2(M) nanorods showed a reversible phase transition temperature at about 62.5 °C and a narrow thermal hysteresis width of 10 °C. The mechanism of the hydrothermal reduction was studied by combined ex situ microscopic and diffraction characterization of cooled samples as well as in situ PXRD experiments, in which the hydrothermal synthesis was monitored in real time by time-resolved diffraction datasets. It was found that the hydrothermal synthesis of VO2(A) is a 4-step process: (1) reduction of V2O5 to form VO2(B) nanoparticles, (2) oriented attachment of VO2(B) nanoparticles along the 110 direction, (3) formation of VO2(B) nanorods as a results of oriented attachments, and (4) hydrothermal transformation of the metastable intermediate VO2(B) nanorods to VO2(A) nanorods. This clear understanding of the mechanism will help the further optimization of synthesis temperature and time for preparing VO2(A). This method provides a low temperature thermal treatment alternative and hence helps the reduction of cost for the production of VO2(M), bring the mass application of VO2(M) one step closer.
This study demonstrates a high-performance visible-light-driven photocatalyst for water splitting H2 production. CdS nanorods (30 nm in diameters) with shorter radial transfer paths and fewer defects ...were prepared by a solvothermal method. To mitigate the recombination of electrons and holes, MoS2 nanosheets with rich active sites were modified on the surface of CdS nanorods by a room-temperature sonication treatment. The photocatalytic water splitting tests show that the MoS2/CdS nanocomposites exhibit excellent H2 evolution rates. The highest H2 evolution rates (63.71 and 71.24 mmol g−1h−1 in visible light and simulated solar light irradiation) was found at the 6% MoS2/CdS nanocomposites, which was 14.61 times and 13.39 times higher than those of the corresponding pristine CdS nanorods in visible light and simulate solar light irradiation, respectively. The apparent quantum efficiency (AQE) of the 6% MoS2/CdS nanocomposites at 420 nm was calculated to be 33.62%. The electrochemistry tests reveal that the enhanced photocatalytic activity is a result of extra photogenerated charge carries, greatly enhanced charge separation and transfer ability of the MoS2/CdS composites. This study may give new insights for the rational design and facile synthesis of high-performance and cost-effective bimetallic sulfide photocatalysts for solar-hydrogen energy conversion.
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•CdS/MoS2 composites were prepared by a room-temperature sonication method.•This material shows excellent photocatalytic H2 production performance.•The decoration of MoS2 nanosheets enables to effectively reduce photo-corrosion.•The performance is due to good separation and transfer ability.
By introducing MoO2–C nanomaterials into Mn0·2Cd0·8S nanorods, the S-scheme heterojunction of MoO2–C/Mn0·2Cd0·8S with unique interface microstructure was successfully constructed. It is worth ...mentioning that there is a disorder region in MoO2–C nanocomposites, which provides the main active center for photocatalytic decomposition of water. Photoelectrochemical tests show that the existence of S-scheme heterojunction and carbon rod leads to the rapid separation of charge and the effectively decrease of hydrogen evolution potential. S-scheme heterojunction can promote the charge separation and transfer between MoO2–C and Mn0·2Cd0·8S quickly and effectively. Compared with pure Mn0·2Cd0·8S, MOCMCS has high hydrogen evolution activity, and its activity is about 13 times higher. The significant improvement of photocatalytic performance is due to the existence of S-scheme heterostructure between MoO2–C/MCS and small transfer resistance, coupled with the excellent conductivity of carbon rods, which effectively promote the charge separation and transfer between MoO2–C and Mn0·2Cd0·8S nanorods.
•There is a disorder zone on the interface between carbon material and MoO2 crystal plane.•S-scheme heterojunction composed of MoO2–C and Mn0·2Cd0·8S was formed.•The presence of carbon rods greatly inhibits the recombination of photogenerated electron-hole pairs.
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Manganese dioxide (MnO2) with high theoretical capacity (1380 F g−1), high natural abundance and low cost has been considered as one of the most competitive active materials for ...preparing the electrode of supercapacitors. However, the poor electrical conductivity limits its broad applications. To solve this problem, we design a hierarchical Cu(OH)2@MnO2 core-shell nanorods array on copper foam (CF), in which the one-dimensional (1D) Cu(OH)2 nanorod core provides the scaffold for the growth of MnO2 nanosheets and a short ion and electronic diffusion pathway and the two-dimensional (2D) MnO2 nanosheets shell provides enormous active sites due to their large surface area. The obtained Cu(OH)2@MnO2/CF nanorods array displays an excellent areal capacitance of 708.62 mF cm−2 at the current density of 2 mA cm−2 (283.45 F g−1 at 0.8 A g−1). Additionally, the assembled Cu(OH)2@MnO2/CF//activated carbon (AC) asymmetric supercapacitor shows an outstanding energy density of 18.36 Wh kg−1 at a power density of 750 W kg−1. Two such capacitors connected in series can light up a red LED bulb for over fifteen minutes.
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