This paper presents an in situ chemical vapor reaction in a molten salt (KOH–NaOH, MS) for the synthesis of Pt nanosheets. Unlike conventional solution phase synthesis of nanoparticles in organic and aqueous solutions, no organic surfactant or capping agent was used. The surfactant-free Pt nanosheets were used directly to prepare oxygen reduction electrocatalysts without carbon supports and showed little loss of electrochemical surface area in the accelerated durability test. As the MS has a low vapor pressure under ambient pressure, this approach should also have environmental benefits because of reduced risk for releasing toxic gases from volatile organic solvents (VOCs).
Design and synthesis of environmentally friendly adsorbents with high adsorption capacities are urgently needed to control pollution of water resources. In this work, a calcium ion-induced approach was used to synthesize sodium alginate fibroid hydrogel (AFH). The as-prepared AFH has certain mechanical strength, and the mechanical strength is enhanced especially after the adsorption of heavy metal ions, which is very convenient for the recovery. AFH exhibited excellent adsorption performances for Cu2+, Cd2+ and Pb2+ ions and displayed very high saturated adsorption capacities (Qe) of 315.92 mg·g-1 (Cu2+), 232.35 mg·g-1 (Cd2+) and 465.22 mg·g-1 (Pb2+) with optimized pH values (3.0-4.0) and temperature (303 K). The study of isotherms and kinetics indicated that adsorption processes of heavy metal ions fitted well with the pseudo-second-order kinetics model and the Langmuir model. Pb2+ was found to have the strongest competitiveness among the three heavy metal ions. Thus, AFH has great application prospects in the field of heavy metal ions removing from wastewater.
The template-strategy is one of the most significant techniques for the controllable synthesis of hollow architectures with unique structures, morphologies and properties. In this review, we selectively summarize the general principles of the Cu2O-templated strategy for the synthesis of definable hollow architectures and cover the recent progress in this area. We elaborate on the use of low-cost Cu2O templates for synthesizing different types of hollow cages (including copper sulfide, metal oxide, and metal) categorized by their chemical reaction mechanisms, followed by the challenges and perspective on Cu2O-templated strategy and its potential future directions.
Abstract Heterogeneous architecture of Cu 2 O‐based composite has exhibited beneficial effort in the CO oxidation, due to the low cost and the multiple oxidation states. In this work, Cu–Cu 2 O heterogeneous particles (HPs) comprising uniformly distributed Cu nanoparticles anchored on the Cu 2 O surface are synthesized by in situ reduction reaction. Comparing with the pure Cu 2 O particles, Cu–Cu 2 O HPs exhibit enhanced and stable catalytic performance during CO oxidation. Moreover, both the transformation of interface and the role of loaded Cu nanoparticle at a molecular level are investigated to analyze the promotion, suggesting that the surface of Cu–Cu 2 O HPs can be spontaneously oxidized to a composite interface during the CO oxidation. The density functional theory (DFT) simulations indicate that due to loaded Cu nanoparticles, the heterogeneous architecture promotes the catalytic reaction under both the Eley–Rideal mechanism as well as Langmuir–Hinshelwood mechanism. As a result, the composite interface and loaded Cu nanoparticles together play the synergistic effect of enhanced CO oxidation.
In this review, we comprehensively summarize the important advances in hollow CuxO micro/nanostructures, including the universal synthesis strategies, the interfacial Cu–O atomic structures as well as the intrinsic properties, and potential applications. Remarks on emerging issues and promising research directions are also discussed.
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