Electroluminescence and Photocatalytic Hydrogen Evolution of S,N Co-doped Graphene Oxide Quantum Dots

A facile hydrothermal route to synthesize S,N co-doped graphene oxide quantum dots (S,N-GOQDs) with stable electroluminescence, photoluminescence, and photocatalytic properties was demonstrated. The synthesized S,N-GOQDs show high yield and excitation–independent...

A highly efficient photocatalyst based on layered g-C3N4/SnS2 composites

Background: In this report, the layered g-C3N4/SnS2 composite was successfully fabricated by a facile hydrothermal route. Methods: The ultraviolet-visible spectroscopy data presented that such layered g-C3N4/SnS2 catalysts showed a remarkable visible-light absorption, hence significantly enhancing the catalytic activity. Particularly, the g-C3N4/SnS2 catalysts showed an outstanding catalytic performance for the degradation of methylene blue (~ 98.1%) under visible light irradiation that is much better than that of pure SnS2 (~ 86.7%) and pure g-C3N4 (~ 67.3%). Results: The remarkable photocatalytic performance is ascribed to its layer structure resulting in a large surface area, which not only improves the ion transfer rate but also provides abundant surface reaction sites. Conclusion: Our work demonstrates that the layered g-C3N4/SnS2 can be considered as an exceptional candidate for highly-efficient photocatalyst.

MOF Embedded and Cu Doped CeO2 Nanostructures as Efficient Catalyst for Adipic Acid Production: Green Catalysis

Greatly efficient chemical processes are customarily based upon a catalyst activating the process pathway to achieve higher yields of a product with desired specifications. Catalysts capable of achieving good performance without compromising green credentials are a pre-requisite for the development of a sustainable process. In this study, CeO2 nanoparticles were tested for their catalytic activity with two different configurations, one as a hybrid of CeO2 nanoparticles with Zeolitic Immidazole Framework (ZIF-67) and second being doped Cu cations into CeO2 nanoparticles. Physicochemical and catalytic activity was investigated and compared for both systems. Each hybrid was synthesized by embedding the CeO2 nanoparticles into the microporous structure of ZIF-67, and Cu doped CeO2 nanoparticles were prepared by a facile hydrothermal route. As a catalytic test, it was employed for the oxidation of cyclohexene to adipic acid (AA) as an alternative to expensive noble metal-based catalysts. Heterogeneous ZIF-67/CeO2 found catalytical activity towards the oxidation of cyclohexene with nearly complete conversion of cyclohexene into AA under moderate and co-catalyst free reaction conditions, whereas Cu doped CeO2 nanoparticles have shown no catalytic activity towards cyclohexene conversion, depicting the advantages of the porous ZIF-67 structure and its synergistic effect with CeO2 nanoparticles. The large surface area catalyst could be a viable option for the green synthesis of many other chemicals.

Hybrid ZnCo2O4@Co3S4 Nanowires for High-Performance Asymmetric Supercapacitors

We successfully fabricate hierarchical ZnCo2O4@Co3S4 nanowires directly supported on nickel foam by a facile hydrothermal route. The as-synthesized product possesses large specific surface area and short reaction path, which result in superior electrochemical performances as the electrode of supercapacitor (SC). The obtained electrode material shows high area capacitance of 2.02 C g-1 at current density of 0.8 A g-1 with 95.3% retention of initial capacitance after 6000 cycles. Moreover, the assembled asymmetric supercapacitor (ASC) device using ZnCo2O4@Co3S4 nanowires as anode material displays noticeable electrochemical capability with an energy density of 79.8 mW h g-1 at power density of 1795 W kg-1 and 73.2 mW h g-1 at 9760 W kg-1. In addition, the device shows remarkable cycling capability, maintaining 82.2% retention after long-term cycles. It reveals the as-fabricated material would be promising energy storage materials.

Facile Hydrothermal Synthesis of Fe2O3/rGO Composites for Low-Cost Supercapacitors

In this work, Fe2O3/rGO composites with high capacitive performance were synthesized via a facile hydrothermal route. The morphological and structural characteristics of the synthesized material were obtained by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The three-electrode system was employed for investigating the electrochemical performance in 6 M aqueous electrolytic solution of KOH. The electrochemical data reveals that the Fe2O3/20%rGO shows as high as 171 F g[Formula: see text] specific capacitance at 1 A g[Formula: see text] discharge current density within the operated voltage window −0.9[Formula: see text]V–0[Formula: see text]V, which is 55% higher than that of the bare Fe2O3. After 1000 cycles, the capacity reservation was retained at 74%. The results indicate that the synthesized Fe2O3/rGO material could be a potential candidate for applications in an environmentally friendly commercial electrode.

Controllable Hydrothermal Synthesis and Photocatalytic Performance of Bi2MoO6 Nano/Microstructures

Bi2MoO6 with a tunable morphology was synthesized by a facile hydrothermal route using different surfactants, including nanosheet-assembled microspheres, smooth microspheres, nanoparticle aggregates and nanoparticles. The morphology, crystal structure and photocatalytic activity of as-obtained Bi2MoO6 were characterized by scanning electron microscopes (SEM), X-ray diffraction (XRD), photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) and UV–Vis spectrophotometer. Bi2MoO6 flower-like microspheres using cetyl-trimethyl-ammonium bromide (BET) as the surfactant exhibited much better photocatalytic activity than Bi2MoO6 with the other morphologies, with a degradation efficiency of 98.4%. It can be summarized that the photocatalytic activity of Bi2MoO6 samples depends on their morphology and composition.