Crystal facet engineering is an effective strategy for precisely regulating the orientations and electrochemical properties of metal oxides. However, the contribution of each crystal facet to pseudocapacitance is still puzzling, which is a bottleneck that restricts the specific capacitance of metal oxides. Herein, α-MnO nanorods with different exposed facets were synthesized through a hydrothermal route and applied to pseudocapacitors. XRD and TEM results verified that the exposure ratio of active crystal facets was significantly increased with the assistance of the structure-directing agents. XPS analysis showed that there was more adsorbed oxygen and Mn on the active crystal facets, which can provide strong kinetics for the electrochemical reaction. Consequently, the α-MnO nanorods with {110} and {310} facets exhibited much higher pseudocapacitances of 120.0 F g and 133.0 F g than their α-MnO-200 counterparts (67.5 F g). The theoretical calculations proved that the {310} and {110} facets have stronger adsorption capacity and lower diffusion barriers for sodium ions, which is responsible for the enhanced pseudocapacitance of MnO. This study provides a strategy to enhance the electrochemical performance of metal oxide, based on facet engineering.
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http://dx.doi.org/10.1039/d3nr04274j | DOI Listing |
Nat Commun
December 2024
Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
Nanoporous metals have unique potentials for energy applications with a high surface area despite the percolating structure. Yet, a highly corrosive environment is required for the synthesis of porous metals with conventional dealloying methods, limiting the large-scale fabrication of porous structures for reactive metals. In this study, we synthesize a highly reactive Mg nanoporous system through a facile organic solution-based approach without any harsh etching.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
College of Materials Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, PR China. Electronic address:
NH-MIL-125 with abundant porosity and specific interactions with CO molecules, has been demonstrate great potential in the field of photocatalytic CO reduction. However, conventional NH-MIL-125 and their composites much lower CO photoreduction efficiency in aerobic environments because of the O competition. To circumvent the issue, this study modifies NH-MIL-125 through crystal facet engineering to enhance its selective CO adsorption and photocatalytic efficiency in the environment of impurity CO.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
NEST Lab., Department of Chemistry, College of Science, Shanghai University, 99 Shangda Road, Shanghai 200444, China. Electronic address:
It is well known that metals and metal oxides with different crystal facets exhibit varying sensitivity in gas sensors, but this strategy is rarely used in metal-organic frameworks (MOFs). Herein, we proved for the first time that Cu metal-organic with high energy crystal facets (Cu-MOF-74-300) shows a much higher sensitivity than the low energy crystal facets (Cu-MOF-74-110), with a up to 2 times response more than Cu-MOF-74-110 and ultra-low limit of detection (LOD) of 68 ppb to toluene vapors. In addition, this strategy was further demonstrated on MOF-14 and HKUST-1, which are also Cu-centered and exhibit clear recognition effects on benzene and xylene, respectively.
View Article and Find Full Text PDFACS Nanosci Au
December 2024
Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
Colloidal nanoparticle assembly methods can produce intricate superlattice structures and often use knowledge of atomic crystallization behaviors to guide their design. While this analogy has enabled multiple routes to programming colloidal crystallization thermodynamics, fewer tools or strategies exist to manipulate nanoparticle superlattice growth kinetics in a controlled manner. Here we investigate how small-molecule additives can be used to modulate the thermodynamics and kinetics of supramolecular-chemistry-driven nanoparticle assembly.
View Article and Find Full Text PDFACS Nanosci Au
December 2024
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Acidic oxygen evolution reaction (OER) has long been the bottleneck of proton exchange membrane water electrolysis. Ru- and Ir-based oxides are currently state-of-the-art electrocatalysts for acidic OER, but their high cost limits their widespread application. CoO is a promising alternative, yet the performance requires further improvement.
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