The fast industrialization process has led to global challenges in the energy crisis and environmental pollution, which might be solved with clean and renewable energy. Highly efficient ...electrochemical systems for clean‐energy collection require high‐performance electrocatalysts, including Au, Pt, Pd, Ru, etc. Graphene, a single‐layer 2D carbon nanosheet, possesses many intriguing properties, and has attracted tremendous research attention. Specifically, graphene and graphene derivatives have been utilized as templates for the synthesis of various noble‐metal nanocomposites, showing excellent performance in electrocatalytic‐energy‐conversion applications, such as the hydrogen evolution reaction and CO2 reduction. Herein, the recent progress in graphene‐based noble‐metal nanocomposites is summarized, focusing on their synthetic methods and electrocatalytic applications. Furthermore, some personal insights on the challenges and possible future work in this research field are proposed.
Recent progress in the study of graphene‐based noble‐metal nanocomposites is reviewed. Different strategies regarding the synthesis of noble‐metal nanostructures on graphene or its derivatives are presented. Their applications in electrocatalysis including the hydrogen evolution reaction, oxygen reduction reaction, alcohol oxidation reaction, and CO2 reduction reaction are discussed.
Hydrogen (H2) is one of the most important clean and renewable energy sources for future energy sustainability. Nowadays, photocatalytic and electrocatalytic hydrogen evolution reactions (HERs) from ...water splitting are considered as two of the most efficient methods to convert sustainable energy to the clean energy carrier, H2. Catalysts based on transition metal dichalcogenides (TMDs) are recognized as greatly promising substitutes for noble‐metal‐based catalysts for HER. The photocatalytic and electrocatalytic activities of TMD nanosheets for the HER can be further improved after hybridization with many kinds of nanomaterials, such as metals, oxides, sulfides, and carbon materials, through different methods including the in situ reduction method, the hot‐injection method, the heating‐up method, the hydro(solvo)thermal method, chemical vapor deposition (CVD), and thermal annealing. Here, recent progress in photocatalytic and electrocatalytic HERs using 2D TMD‐based composites as catalysts is discussed.
Transition‐metal dichalcogenide (TMD)‐based catalysts have great promise as substitutes for noble‐metal‐based catalysts for hydrogen‐evolution reactions. Recent strategies regarding the various kinds of TMD‐based composites for photocatalytic and electrocatalytic hydrogen evolution are summarized here. In addition, the challenges and opportunities are provided.
Two‐dimensional (2D) metal–organic framework (MOF) nanosheets are attracting increasing research interest due to their unique properties originating from their ultrathin thickness and large surface ...area with highly accessible active sites. Here, the aim is to provide recent advances in the synthesis of 2D MOF nanosheets by using the top‐down and bottom‐up methods, including sonication exfoliation, interfacial synthesis, three‐layer synthesis, and surfactant‐assisted synthesis methods. In addition, the recent progress in 2D‐MOF‐nanosheet‐based nanocomposites is also introduced. The synthesis of 2D MOF nanosheets should lead to new kinds of functional nanomaterials for a wide range of applications.
Recent advances in the synthesis of 2D metal–organic framework (MOF) nanosheets using the top‐down and bottom‐up methods are summarized, including sonication exfoliation, interfacial synthesis, three‐layer synthesis, and surfactant‐assisted synthesis methods. In addition, the recent progress in 2D‐MOF‐nanosheet‐based nanocomposites is also introduced.
Capturing CO
2
from the atmosphere and converting it into fuels are an efficient strategy to stop the deteriorating greenhouse effect and alleviate the energy crisis. Among various CO
2
conversion ...approaches, electrocatalytic CO
2
reduction reaction (CO
2
RR) has received extensive attention because of its mild operating conditions. However, the high onset potential, low selectivity toward multi-carbon products and poor cruising ability of CO
2
RR impede its development. To regulate product distribution, previous studies performed electrocatalyst modification using several universal methods, including composition manipulation, morphology control, surface modification, and defect engineering. Recent studies have revealed that the cathode and electrolytes influence the selectivity of CO
2
RR via pH changes and ionic effects, or by directly participating in the reduction pathway as cocatalysts. This review summarizes the state-of-the-art optimization strategies to efficiently enhance CO
2
RR selectivity from two main aspects, namely the cathode electrocatalyst and the electrolyte.
A facile surfactant‐assisted bottom‐up synthetic method to prepare a series of freestanding ultrathin 2D M‐TCPP (M = Zn, Cu, Cd or Co, TCPP = tetrakis(4‐carboxyphenyl)porphyrin) nanosheets with a ...thickness of sub‐10 nm is developed. As a proof‐of‐concept application, some of them are successfully used as new platforms for DNA detection. The Cu‐TCPP nanosheet‐based sensor shows excellent fluorescent sensing performance and is used for the simultaneous detection of multiple DNA targets.
Inspired by the multiple functions of natural multienzyme systems, a new kind of hybrid nanosheet is designed and synthesized, i.e., ultrasmall Au nanoparticles (NPs) grown on 2D metalloporphyrinic ...metal‐organic framework (MOF) nanosheets. Since 2D metalloporphyrinic MOF nanosheets can act as the peroxidase mimics and Au NPs can serve as artificial glucose oxidase, the hybrid nanosheets are used to mimic the natural enzymes and catalyze the cascade reactions. Furthermore, the synthesized hybrid nanosheets are used to detect biomolecules, such as glucose. This study paves a new avenue to design nanomaterial‐based biomimetic catalysts with multiple complex functions.
Inspired by the multiple functions of natural multienzyme systems, hybrid nanosheets are designed and synthesized, i.e., ultrasmall Au nanoparticles are grown on 2D metalloporphyrinic metal‐organic framework nanosheets. Since nanosheets can act as the peroxidase mimics and Au nanoparticles can serve as artificial glucose oxidase, the hybrid nanosheets are used to mimic the natural enzymes and catalyze the cascade reactions.
Solar‐thermal water evaporation, as a promising method for clean water production, has attracted increasing attention. However, solar water evaporators that exhibit both high water vapor generation ...ability and anti‐oil‐fouling ability have not been reported. Here, a unique metal–organic‐framework‐based hierarchical structure, referred to as MOF‐based hierarchical structure (MHS), is rationally designed and prepared, which simultaneously displays a high solar absorption and a superhydrophilic and underwater superoleophobic surface property. As a proof‐of‐concept application, a device prepared from the MHS can achieve a high solar‐thermal water evaporation rate of 1.50 kg m−2 h−1 under 1 sun illumination. Importantly, the MHS also possesses an excellent anti‐oil‐fouling property, ensuring its superior water evaporation performance even in oil‐contaminated water. The high solar‐thermal water evaporation rate and anti‐oil‐fouling property make the MHS a promising material for the solar‐thermal water production.
The first metal–organic framework (MOF)‐based solar–thermal water evaporator is designed and fabricated with a unique hierarchical structure, which simultaneously enhances the light absorbance and promotes the superhydrophilic and underwater superoleophobic property. As a result, a high water evaporation rate is achieved even in oil‐contaminated water.
With the bioinspired design of organic ligands and metallic nodes, novel ultrathin 2D bimetallic metal–organic‐framework nanosheets are successfully synthesized, which can serve as advanced 2D ...biomimetic nanomaterials to mimic heme proteins.
Metal–organic framework (MOF) heterostructures have shown promising applications in gas adsorption, gas separation, catalysis, and energy, arising from the synergistic effect of each component. ...However, owing to the difficulty in controlling the size, shape, nucleation, and growth of MOFs, it remains a great challenge to construct MOF heterostructures with precisely controlled orientation, morphology, dimensionality, and spatial distribution of each component. Here, we report a seeded epitaxial growth method to prepare a series of hierarchical MOF heterostructures by engineering the structures, sizes, dimensionalities, morphologies, and lattice parameters of both MOF seeds and the secondary MOFs. In these heterostructures, PCN-222 (also known as MOF-545) nanorods selectively grow along the major axis of the ellipsoid-like PCN-608 nanoparticles, on the two end facets of the hexagonal prism-like NU-1000 nanorods, and on the two basal planes of the hexagonal PCN-134 nanoplates, while Zr–BTB nanosheets selectively grow on the six edge facets of PCN-134 nanoplates. The selective epitaxial growth of MOFs opens the way to synthesize different hierarchical heterostructures with tunable architectures and dimensionalities, which could process various promising applications.
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