The continuous exploration of clean‐energy technology is critical for the sustainable development of society. The recent work on the electric energy harvesting from water evaporation has made a ...significant contribution to the utilization of clean energy for self‐powering systems. Here, a novel metal–organic‐framework‐based hybrid nanomaterial is delicately designed and synthesized by the growth of UIO‐66 nanoparticles on 2D AlOOH nanoflakes. Due to the combined merits from the 2D morphology, which is inherited from the AlOOH nanoflakes, and the high surface potential, which originates from the UIO‐66 nanoparticles, the device made of the AlOOH/UIO‐66 hybrid nanomaterials can harvest electric energy from natural water evaporation. An open‐circuit voltage of 1.63 ± 0.10 V can be achieved on the prototype devices made of the hybrid nanomaterial. As a proof‐of‐concept application, a small electric appliance, e.g., a digital calculator, is powered up by a 3 × 3 device array connected in a combined series–parallel configuration.
A metal–organic framework (MOF)‐based hybrid nanomaterial is rationally designed and synthesized. Due to the 2D morphology and high surface potential, a prototype device made of MOF‐based hybrid nanomaterials can efficiently harvest the electric energy from water evaporation.
Transition‐metal dichalcogenides (TMDs) have attracted considerable attention in recent years because of their unique properties and promising applications in electrochemical energy storage and ...conversion. However, the limited number of active sites as well as blocked ion and mass transport severely impair their electrochemical performance. The construction of three‐dimensional (3D) architectures from TMD nanomaterials has been proven to be an effective strategy to solve the aforementioned problems as a result of their large specific surface areas and short ion and mass transport distances. This Review summarizes the commonly used routes to build 3D TMD architectures and highlights their applications in electrochemical energy storage and conversion, including batteries, supercapacitors, and electrocatalytic hydrogen evolution. The challenges and outlook in this research area are also discussed.
Electrochemistry in 3D: Three‐dimensional transition‐metal dichalcogenide architectures have shown great promise for electrochemical energy storage and conversion. This Review summarizes the commonly used strategies for the construction of such architectures, as well as their application in rechargeable batteries, supercapacitors, and electrocatalytic hydrogen evolution.
Since the discovery of graphene, diverse kinds of 2D nanomaterials have been explored and exhibited great promise for application in electrochemical energy storage and conversion. However, the ...restacking of 2D nanomaterials severely reduces their exposed active sites and thus impairs their electrochemical performance. Moreover, except for graphene, a large number of 2D nanomaterials normally possess unsatisfactory electrical conductivity. One of the effective strategies to address the aforementioned shortcomings is to hybridize 2D nanomaterials with 3D graphene architectures since large specific surface area and rapid transport pathways for electrons, ions, and mass can be achieved in the obtained hybrid materials. This review summarizes the typical strategies to hybridize 2D nanomaterials with 3D graphene architectures and then highlights the application of these hybrid materials in rechargeable batteries, supercapacitors, and electrocatalytic water splitting. The challenges and future research directions in this research area are also discussed.
The hybridization of 2D nanomaterials with 3D graphene architectures has offered a promising strategy to prepare high‐performance hybrid materials for electrochemical energy storage and conversion. This review summarizes the typical methods to hybridize 2D nanomaterials with 3D graphene architectures, as well as their application in rechargeable batteries, supercapacitors, and electrocatalytic water splitting.
Various kinds of amorphous materials, such as transition metal dichalcogenides, metal oxides, and metal phosphates, have demonstrated superior electrocatalytic performance compared with their ...crystalline counterparts. Compared to other materials for electrocatalysis, noble metals exhibit intrinsically high activity and excellent durability. However, it is still very challenging to prepare amorphous noble‐metal nanomaterials due to the strong interatomic metallic bonding. Herein, the discovery of a unique thiol molecule is reported, namely bismuthiol I, which can induce the transformation of Pd nanomaterials from face‐centered‐cubic (fcc) phase into amorphous phase without destroying their integrity. This ligand‐induced amorphization is realized by post‐synthetic ligand exchange under ambient conditions, and is applicable to fcc Pd nanomaterials with different capping ligands. Importantly, the obtained amorphous Pd nanoparticles exhibit remarkably enhanced activity and excellent stability toward electrocatalytic hydrogen evolution in acidic solution. This work provides a facile and effective method for preparing amorphous Pd nanomaterials, and demonstrates their promising electrocatalytic application.
A unique thiol molecule, namely bismuthiol I, is discovered, which can induce the amorphization of Pd nanomaterials by ligand exchange under ambient conditions. This method is applicable to different kinds of Pd nanomaterials without destroying their integrity. Notably, the obtained amorphous Pd nanoparticles show dramatically enhanced electrocatalytic activity and excellent durability toward the hydrogen evolution reaction.
Similar to heterostructures composed of different materials, possessing unique properties due to the synergistic effect between different components, the crystal‐phase heterostructures, one variety ...of hetero‐phase structures, composed of different crystal phases in monometallic nanomaterials are herein developed, in order to explore crystal‐phase‐based applications. As novel hetero‐phase structures, amorphous/crystalline heterostructures are highly desired, since they often exhibit unique properties, and hold promise in various applications, but these structures have rarely been studied in noble metals. Herein, via a one‐pot wet‐chemical method, a series of amorphous/crystalline hetero‐phase Pd nanosheets is synthesized with different crystallinities for the catalytic 4‐nitrostyrene hydrogenation. The chemoselectivity and activity can be fine‐tuned by controlling the crystallinity of the as‐synthesized Pd nanosheets. This work might pave the way to preparing various hetero‐phase nanostructures for promising applications.
Amorphous/crystalline heterophase Pd nanosheets exhibit crystallinity‐dependent chemoselectivity and catalytic activity.
A 3D porous Cu current collector is fabricated through chemical dealloying from a commerial Cu–Zn alloy tape. The interlinked porous framework naturally integrated can accommodate Li deposition, ...suppressing dendrite growth and alleviating the huge volume change during cycling. The Li metal anode combined with such a porous Cu collector demonstrates excellent performance and commerial potentials in Li‐based secondary batteries.
As the best electrocatalysts for alcohol oxidation reactions in direct alcohol fuel cells (DAFCs), Pt‐based nanomaterials still face the challenges of low utilization efficiency of Pt atoms and poor ...reaction kinetics. To address these issues, a self‐etching strategy is developed to prepare PtBi nanorings (NRs) with abundant low‐coordinated atoms and inhomogeneous tensile strain (≈4%). The obtained PtBi NRs exhibit superior activity toward methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR) in alkaline media. Particularly, the mass activities of PtBi NRs for MOR and EOR are 9.4 and 8.5 times higher than those of commercial Pt/C, respectively, which are among the best in the reported Pt‐based catalysts. The highly open structure of PtBi NRs is believed to provide plentiful catalytic active sites and increase the utilization of Pt atoms. Theoretical calculations show that the two important factors, i.e., adsorption energy with the key reaction intermediates and the energy barrier for the potential‐determining step, are significantly optimized owing to the synergy of tensile strain and the ligand effect in PtBi NRs. This study offers a promising strategy for the rational design and preparation of highly efficient catalysts for DAFCs.
PtBi nanorings with abundant low‐coordinated atoms and inhomogeneous tensile strain (≈4%) are prepared based on a self‐etching strategy. The obtained PtBi nanorings exhibit outstanding electrocatalytic activity and stability toward methanol oxidation reaction and ethanol oxidation reaction in alkaline media.
Electrocatalytic carbon dioxide reduction reaction (CO2RR) holds significant potential to promote carbon neutrality. However, the selectivity toward multicarbon products in CO2RR is still too low to ...meet practical applications. Here the authors report the delicate synthesis of three kinds of Ag–Cu Janus nanostructures with {100} facets (JNS‐100) for highly selective tandem electrocatalytic reduction of CO2 to multicarbon products. By controlling the surfactant and reduction kinetics of Cu precursor, the confined growth of Cu with {100} facets on one of the six equal faces of Ag nanocubes is realized. Compared with Cu nanocubes, Ag65–Cu35 JNS‐100 demonstrates much superior selectivity for both ethylene and multicarbon products in CO2RR at less negative potentials. Density functional theory calculations reveal that the compensating electronic structure and carbon monoxide spillover in Ag65–Cu35 JNS‐100 contribute to the enhanced CO2RR performance. This study provides an effective strategy to design advanced tandem catalysts toward the extensive application of CO2RR.
Through breaking the common symmetric growth, three kinds of silver‐copper Janus nanostructures with {100} facets are synthesized with a wet‐chemical method. Coupling the tandem catalysis, copper {100} facets, and electron transfer between silver and copper, the obtained Janus nanostructures demonstrate excellent Faradaic efficiency toward both ethylene and multicarbon products in electrochemical carbon dioxide reduction reaction.
With the development of phase engineering of nanomaterials (PEN), construction of noble‐metal heterostructures with unconventional crystal phases, including heterophases, has been proposed as an ...attractive approach toward the rational design of highly efficient catalysts. However, it still remains challenging to realize the controlled preparation of such unconventional‐phase noble‐metal heterostructures and explore their crystal‐phase‐dependent applications. Here, various Pd@Ir core–shell nanostructures are synthesized with unconventional fcc‐2H‐fcc heterophase (2H: hexagonal close‐packed; fcc: face‐centered cubic) through a wet‐chemical seeded method. As a result, heterophase Pd66@Ir34 nanoparticles, Pd45@Ir55 multibranched nanodendrites, and Pd68@Ir22Co10 trimetallic nanoparticles are obtained via the phase‐selective epitaxial growth of fcc‐2H‐fcc‐heterophase Ir‐based nanostructures on 2H‐Pd seeds. Importantly, the heterophase Pd45@Ir55 nanodendrites exhibit excellent catalytic performance toward electrochemical hydrogen evolution reaction (HER) under acidic conditions. An overpotential of only 11.0 mV is required to achieve a current density of 10 mA cm−2 on Pd45@Ir55 nanodendrites, which is lower than those of the conventional fcc‐Pd47@Ir53 counterparts, commercial Ir/C and Pt/C. This work not only demonstrates an appealing route to synthesize novel heterophase nanomaterials for promising applications in the emerging field of PEN, but also highlights the significant role of the crystal phase in determining their catalytic properties.
Pd@Ir core–shell nanostructures with fcc‐2H‐fcc heterophase and different Pd/Ir atomic ratios are prepared via seeded phase‐selective epitaxial growth. The fcc‐2H‐fcc‐heterophase Pd45@Ir55 nanodendrites exhibit superior catalytic performance toward electrochemical hydrogen evolution. This work offers new opportunities toward the rational synthesis of novel heterophase nanostructures and paves a way to the phase engineering of nanomaterials (PEN) for various promising applications.
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