The oxygen evolution reaction (OER) is a kinetically sluggish anodic reaction and requires a large overpotential to deliver appreciable current. Despite the fact that non-precious metal-based ...alkaline water electrocatalysts are receiving increased attention, noble metal-based electrocatalysts (NMEs) applied in proton exchange membrane water electrolyzers still have advantageous features of larger current and power densities with lower stack cost. Engineering NMEs for OER catalysis with high efficiency, durability and utilization rate is of vital importance in promoting the development of cost-effective renewable energy production and conversion devices. In this tutorial review, we covered the recent progress in the composition and structure optimization of NMEs for OER including Ir- and Ru-based oxides and alloys, and noble-metals beyond Ir and Ru with a variety of morphologies. To shed light on the fundamental science and mechanisms behind composition/structure-performance relationships and activity-stability relationships, integrated experimental and theoretical studies were pursued for illuminating the metal-support interaction, size effect, heteroatom doping effect, phase transformation, degradation processes and single-atom catalysis. Finally, the challenges and outlook are provided for guiding the rational engineering of OER electrocatalysts for applications in renewable energy-related devices.
The oxygen evolution reaction (OER) is a kinetically sluggish anodic reaction that requires rationalized compositions and structures for achieving highly efficient and reliable noble metal-based electrocatalysts in acidic electrolyte.
Recent years have witnessed a dramatic increase in the production of sustainable and renewable energy. However, the electrochemical performances of the various systems are limited, and there is an ...intensive search for highly efficient electrocatalysts by more rational control over the size, shape, composition, and structure. Of particular interest are the studies on single‐atom catalysts (SACs), which have sparked new interests in electrocatalysis because of their high catalytic activity, stability, selectivity, and 100 % atom utilization. In this Review, we introduce innovative syntheses and characterization techniques for SACs, with a focus on their electrochemical applications in the oxygen reduction/evolution reaction, hydrogen evolution reaction, and hydrocarbon conversion reactions for fuel cells (electrooxidation of methanol, ethanol, and formic acid). The electrocatalytic performance is further considered at an atomic level and the underlying mechanisms are discussed. The ultimate goal is the tailoring of single atoms for electrochemical applications.
When less is more: Single‐atom electrocatalysts are characterized by high catalytic activity, selectivity, and maximum metal utilization. They hold great promise in various electrochemical applications, such as the oxygen reduction reaction, the hydrogen evolution reaction, and hydrocarbon conversion reactions for fuel cells.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Due to their unique structures and multifunctionalities, two-dimensional (2D) nanomaterials have aroused increasing interest in the construction of the novel biointerfaces for biosensing ...applications. Efforts in constructing novel biointerfaces led to exploit the more versatile and tunable graphene-like 2D nanomaterials (e.g. graphitic carbon nitride, boron nitride, transition metal dichalcogenides, and transition metal oxides) with various structural and compositional characteristics. This review highlights recent efforts in the design of graphene-like 2D nanomaterials and their derived biointerfaces and exploitation of their research on fluorescent sensors and a series of electrochemical sensors, including amperometric, electrochemiluminescence, photoelectrochemical and field-effect transistor sensors. Finally, we discuss some critical challenges and future perspectives in this field.
•Graphene-like 2D nanomaterials are promising in designing functional biointerfaces.•We review graphene-like 2D nanomaterial-based electrochemical sensors.•We review graphene-like 2D nanomaterial-based fluorescent sensors.•Rational design of novel graphene-like nanomaterial-based biointerfaces is summarized.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Aliphatic trifluoromethyl ketones are a type of unique fluorine-containing subunit which plays a significant role in altering the physical and biological properties of molecules. However, catalytic ...methods to provide direct access to aliphatic trifluoromethyl ketones is highly desirable yet remains underdeveloped, partially due to the high reactivity and instability of trifluoroacetyl radical. Herein, we report a photocatalytic synthesis of trifluoromethyl ketones from alkyl bromides with trifluoroacetic anhydride. The reaction features a dual catalysis of visible-light and XAT reaction, followed by an enabling radical-radical cross-coupling of alkyl radical with a stabilized trifluoromethyl radical. The reaction provides the first straightforward access to aliphatic trifluoromethyl ketones from easily-available and cost-effective alkyl halides and TFAA.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Direct and selective synthesis of primary amines from easily available precursors is attractive yet challenging. Herein, we report the rapid synthesis of primary amines from alkenes via metal‐free ...regioselective hydroamination at room temperature. Ammonium carbonate was used as ammonia surrogate for the first time, allowing for efficient conversion of terminal and internal alkenes into linear, α‐branched, and α‐tertiary primary amines under mild conditions. This method provides a straightforward and powerful approach to a wide spectrum of advanced, highly functionalized primary amines which are of particular interest in pharmaceutical chemistry and other areas.
A straightforward and modular route to a wide variety of aliphatic primary amines from alkenes is presented based on a metal‐free hydroamination at room temperature. The use of cost‐effective and easily available ammonium carbonate allows for the efficient conversion of terminal and internal alkenes with diverse substitution patterns into highly functionalized linear, α‐branched, and α‐tertiary primary amines.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The main purpose of this research is to explore the effects of technological factors on energy intensity, including indigenous research and development (R&D) activity, technology spillovers through ...openness in the form of foreign direct investment, export, and import in one united framework. By scrutinising panel data of China's 30 provinces from 2000 to 2013, this article first uses fixed effects and feasible generalised least squares to investigate the effects of these technological factors on energy intensity by taking both economic structure and energy price as control variables. The results show that indigenous R&D plays a crucial and dominant role in the declining energy intensity among the four technological factors. In addition, technology spillovers coming from the openness of foreign direct investment and import decrease energy intensity except for the export. However, further estimation with the panel threshold model confirms that the effects of technology spillovers on energy intensity depend on the levels of local inputs of R&D expenditure intensity and the full-time equivalent of R&D personnel, allowing us to formulate different policies and measures aimed at encouraging more efficient use of energy that takes into full consideration the characteristics and situations of the technology spillovers.
•We analyse the effects of different technological factors on energy intensity in China.•The technology spillovers coming from the openness decrease energy intensity except for the export.•Indigenous R&D hampers the export's spillover effect on energy intensity.•Full-time equivalent of R&D personnel promotes the spillover effect on energy intensity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
In this paper, we reported a ZnO quantum dots-based pH-responsive drug delivery platform for intracellular controlled release of drugs. Acid-decomposable, luminescent aminated ZnO quantum dots (QDs) ...were synthesized as nanocarriers with ultrasmall size (∼3 nm). The dicarboxyl-terminated poly(ethylene glycol) (PEG) had been introduced to NH2–ZnO QDs, which rendered it stable under physiological fluid. Moreover, a targeting ligand, hyaluronic acid (HA), was conjugated to ZnO QDs for specifically binding to the overexpressed glycoprotein CD44 by cancer cells. Doxorubicin (DOX) molecules were successfully loaded to PEG functionalized ZnO QDs via formation of metal–DOX complex and covalent interactions. The pH-sensitive ZnO QDs dissolved to Zn2+ in acidic endosome/lysosome after uptake by cancer cells, which triggered dissociation of the metal–drug complex and a controlled DOX release. As result, a synergistic therapy was achieved due to incorporation of the antitumor effect of Zn2+ and DOX.
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IJS, KILJ, NUK, PNG, UL, UM
