The composite catalysts of Cu/Cux O nanoparticles supported on the carbon fibers were prepared for styrene oxidation reaction

Electrospun Fe2C-loaded carbon nanofibers as efficient electrocatalysts for oxygen reduction reaction

Carbon-based non-precious metal catalysts have been regarded as the most promising alternatives to the state-of-art Pt/C catalyst for the oxygen reduction reaction (ORR). However, there are still some unresolved challenges such as agglomeration of nanoparticles, complex preparation process and low production efficiency, which severely hamper the large-scale production of non-precious metal catalysts. Herein, a novel carbon-based non-precious metal catalyst, i.e. iron carbide nanoparticles embedded on carbon nanofibers (Fe₂C/CNFs), prepared via the direct pyrolysis of carbon- and iron-containing Janus fibrous precursors obtained by electrospinning. The Fe₂C/CNF catalyst shows uniform dispersion and narrow size distribution of Fe₂C nanoparticles embedded on the CNFs. The obtained catalyst exhibits positive onset potential (0.87 V versus RHE), large kinetic current density (1.9 mA cm^-2), and nearly follows the effective four-electron route, suggesting an outstanding electrocatalytic activity for the ORR in 0.1 M of KOH solution. Besides, its stability is better than that of the commercial Pt/C catalyst, due to the strong binding force between Fe₂C particles and CNFs. This strategy opens new avenues for the design and efficient production of promising electrocatalysts for the ORR.

Novel ZnO/NiO Janus-like nanofibers for effective photocatalytic degradation

In recent years, Janus materials have become a research hotspot in the field of materials science; however, fabricating inorganic Janus-like nanofibers (NFs) is still a challenge. Herein, we report novel ZnO/NiO Janus-like NFs with efficient photocatalytic performance via an electrospinning method followed by calcination treatment. The morphology, structure, chemical composition and crystallinity of ZnO/NiO Janus-like NFs were studied in detail via SEM, TEM, HRTEM, EDS, FT-IR, XPS and XRD, indicating that the NFs had a perfect Janus-like structure composed of ZnO and NiO. A series of photocatalytic experiments were carried out in aqueous organic dye solutions under 365 nm UV radiation for 1 h, with the degradation rate of malachite green able to reach 96%, proving that the NFs have great potential in the field of organic dye degradation. Furthermore, a reasonable catalytic mechanism for the ZnO/NiO Janus-like NFs was proposed, which was discussed from the view of electron-hole pairs and p-n junctions. In short, the method in our work is expected to become a new way of effectively preparing functional inorganic Janus-like NFs.

MOF-Derived Cu@Cu₂O Nanocatalyst for Oxygen Reduction Reaction and Cycloaddition Reaction

Research on the synthesis of nanomaterials using metal-organic frameworks (MOFs), which are characterized by multi-functionality and porosity, as precursors have been accomplished through various synthetic approaches. In this study, copper and copper oxide nanoparticles were fabricated within 30 min by a simple and rapid method involving the reduction of a copper(II)-containing MOF with sodium borohydride solution at room temperature. The obtained nanoparticles consist of a copper core and a copper oxide shell exhibited catalytic activity in the oxygen reduction reaction. The as-synthesized Cu@Cu₂O core-shell nanocatalyst exhibited an enhanced limit current density as well as onset potential in the electrocatalytic oxygen reduction reaction (ORR). Moreover, the nanoparticles exhibited good catalytic activity in the Huisgen cycloaddition of various substituted azides and alkynes under mild reaction conditions.