The micro-supercapacitors are of great value for portable, flexible, and integrated electronic equipments. Here, the large-scale and integrated asymmetrical micro-supercapacitor (AMSC) array is fabricated in virtue of the laser direct writing and electrodeposition technology. The AMSC shows the ideal flexibility, high areal specific capacitance (21.8 mF cm ), and good rate capability. Moreover, its energy density reaches 12.16 µW h cm , outperforming most micro-supercapacitors reported previously. Meanwhile, large-scale series-connected AMSCs are integrated on the flexible substrates (e.g., indium tin oxide-polyethylene terephthalate film), which can power a veriety of the commercial electronics. The combination of AMSCs array, solar cell, and electronic device proves the feasibility for practical application in the portable, flexible, and integrated electronic equipments.
Direct methane oxidation into value‐added organic oxygenates with high productivity under mild condition remains a great challenge. We show Fe‐O clusters on nodes of metal–organic frameworks (MOFs) with tunable electronic state for direct methane oxidation into C1 organic oxygenates at 50 °C. The Fe‐O clusters are grafted onto inorganic Zr6 nodes of UiO‐66, while the organic terephthalic acid (H2BDC) ligands of UiO‐66 are partially substituted with monocarboxylic modulators of acetic acid (AA) or trifluoroacetic acid (TFA). Experiments and theoretical calculation disclose that the TFA group coordinated with Zr6 node of UiO‐66 enhances the oxidation state of adjacent Fe‐O cluster due to its electron‐withdrawing ability, promotes the activation of C−H bond of methane, and increases its selective conversion, thus leading to the extraordinarily high C1 oxygenate yield of 4799 μmol gcat−1 h−1 with 97.9 % selectivity, circa 8 times higher than those modulated with AA.
The
construction of multidimensional, diversified microsupercapacitors
(MSC) is urgently needed for fast-changing flexible and wearable microelectronics,
which still meets the challenges of tedious construction and difficult
integration. Herein, a laser direct writing strategy has been developed
for the one-step preparation of multiscale MSCs from editable macro-supercapacitors.
The microstructured supercapacitors with predefined multiscale shapes
not only maintain the high capacitance performance and stability but
also display the tensile properties in arbitrary direction. The heat-treated
ion liquid-modified reduced graphene oxide guarantees the thermal
stability of an electrode material during laser cutting, and its high
ion-accessible surface area improves the capacitance performance of
the supercapacitor. The as-fabricated MSC demonstrates a wide voltage
window (0–3 V), high areal specific capacitance (27.4 mF cm–2), and high energy density (32.1 μW h cm–2), which are far higher than those of most reported
articles. Notably, the editable supercapacitors can imitate the stereo
paper cutting to achieve an arbitrary one-dimensional to three-dimensional
configuration, promising for various portable, stretchable, and wearable
devices.
Selective
hydrogenation of carbon dioxide (CO2) into
value-added chemicals has aroused great interest. The chemical inertness
of CO2 and diverse reaction pathways usually require the
construction of enabled catalysts. To date, cobalt (Co) catalysts
characteristic of metallic and/or divalent Co components show great
potential for CO2 hydrogenation. To better regulate the
CO2 hydrogenation, it is necessary to summarize the current
progress of cobalt catalysts for selective hydrogenation of CO2. In this Perspective, first, hydrogenation of CO2 into methane over metallic Co sites is introduced. Second, hydrogenation
of CO2 into methanol and C2+ alcohols is discussed
by constructing mixed-valent cobalt sites. Third, hydrogenation of
CO2 into light olefins and C5+ liquid fuels
over cobalt-containing hybrid catalysts is introduced. Fourth, the
reaction paths for selective hydrogenation of CO2 over
cobalt catalysts are illustrated. Finally, the current challenges
and prospects of cobalt-based nanocatalysts for hydrogenation of CO2 are proposed.
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