Remarkably and stable catalytic activity in reduction of 4-nitrophenol by sodium sesquicarbonate-supporting Fe2O3@Pt

Reasonable design of bimetallic nanomaterials with support is beneficial to improve catalytic performance. This work reports a new kind of sodium sesquicarbonate-supporting Fe₂O₃@Pt via etching Fe₃O₄@Pt@SiO₂, which exhibits highly efficient and stable catalytic reduction performance towards 4-NP. Sodium sesquicarbonate-supporting Fe₂O₃@Pt has an interconnected one-dimensional network structure that provides sufficient channels for mass transfer. At the same time, a large amount of Fe₂O₃@Pt is exposed on its surface, which hinders the aggregation of pt clusters and Fe₂O₃ nanoparticles, and facilitates the direct contact of Fe₂O₃@Pt reaction sites with reactant molecules, thus improving the catalytic rate of 4-NP reduction reaction. Moreover, the introduction of non-metallic Fe can not only reduce the consumption of precious metal Pt, but also improve the catalytic efficiency due to the synergistic effect. This study opens up a new avenue to develop robust catalysts for heterogeneous catalytic reactions.

Stabilizing Layered Structure in Aqueous Electrolyte via O2-Type Oxygen Stacking

Despite the high energy density of O3-type layered cathode materials, the short cycle life in aqueous electrolyte hinders their practical applications in aqueous lithium-ion batteries (ALIBs). In this work, it is demonstrated that the structural stability of layered LiCoO₂ in aqueous electrolyte can be remarkably improved by altering the oxygen stacking from O3 to O2. As compared to the O3-type LiCoO₂ , the O2-type LiCoO₂ exhibits significantly improved cycle performance in neutral aqueous electrolyte. It is found that the structural degradation caused by electrophilic attack of proton can be effectively mitigated in O2-type layered structure. With O2 stacking, CoO₆ octahedra in LiCoO₂ possess stronger CoO bonds while Co migration from Co layer to Li layer is strongly hampered, resulting in enhanced structural stability against proton attack and prolonged cycle life in aqueous electrolyte. The findings in this work reveal that regulating oxygen stacking sequence is an effective strategy to improve the structural stability of layered materials for ALIBs.

A study on the high efficiency reduction of p-nitrophenol (4-NP) by a Fe(OH)3/Fe2O3@Au composite catalyst

Precious metal nanometric catalysts are widely used in the removal of harmful substances. In the process of synthesis and catalytic reaction, it is particularly important to study green and simple synthesis methods and high catalytic efficiency. In this paper, a green one-step method was used to synthesize the Fe(OH)₃/Fe₂O₃@Au composite catalyst, in which Au was single atom-dispersed. The removal of 4-nitrophenol (4-NP), a typical dangerous chemical widely existing in factory waste gas, waste water and automobile exhaust gas, was catalysed by Fe(OH)₃/Fe₂O₃@Au. The catalytic performance of Fe(OH)₃/Fe₂O₃@Au with different synthesis conditions (different amounts of MES, NaBH₄, FeSO₄, Au and Pt) on the 4-NP reduction reaction were systematically studied. Finally, the stability and recyclability of Fe(OH)₃/Fe₂O₃@Au composite nanocatalyst were investigated thoroughly.

Development of functional black phosphorus nanosheets with remarkable catalytic and antibacterial performance

Highly dispersed 2D-nanostructured ultrathin black phosphorus nanosheets (BPNs)-integrated Au nanoparticles (AuNPs) hybrids were constructed in situ through a facile and environmentally friendly strategy. No additional reductants, surfactants, or polymer templates were introduced during this green and convenient synthesis process. The resulting AuNPs/BPNs nanohybrids were characterized by UV-vis, Raman spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The content of BPNs plays an essential role in modulating the morphologies and chemical states of AuNPs/BPNs hybrids, which have been investigated systematically and are discussed in detail. As high-density ultrasmall AuNPs are properly stabilized and accommodated without passivation by the surrounding ultrathin BPNs, the resulting AuNPs/BPNs hybrids exhibit excellent catalytic/antibacterial properties and long-term stabilities, benefiting from a possible synergistic enhancement effect between AuNPs and BPNs constructs. This simple, mild and environmentally benign strategy could be generalized to the preparation of other metal- or metal oxide-doped complexes and holds great promise for potential catalytic, bioanalytical and biomedical applications.