The exponentially growing works on 2D materials have resulted in both high scientific interest and huge potential applications in nanocatalysis, optoelectronics, and spintronics. Of especial note is ...that the newly emerged and promising family of metal phosphorus trichalcogenides (MPX3) contains semiconductors, metals, and insulators with intriguing layered structures and architectures. The bandgaps of the members in this family range from 1.3 to 3.5 eV, significantly enriching the application of 2D materials in the broad wavelength spectrum. In this review, emphasizing their remarkable structural, physicochemical, and magnetic properties, as well as the numerous applications in various fields, the innovative progress on layered MPX3 crystals is summarized. Different from other layered materials, these crystals will advance a fascinating frontier in magnetism and spintronic devices with their especially featured atomic layered nanosheets. Thus, their crystal and electronic structures, along with some related researches in magnetism, are discussed in detail. The assortments of growth methods are then summarized. Considering their potential applications, the prominent utilization of these 2D MPX3 nanoscrystals in catalysis, batteries, and optoelectronics is also discussed. Finally, the outlook of these kinds of layered nanomaterials is provided.
Researches on 2D materials have resulted in both high scientific interest and huge potential for a variety of applications. Herein, the frontiers on newly emerged and promising MPX3 family are summarized, which contains semiconductors, metals, and insulators with a special layered structure and architecture. Their compelling structural, physical, chemical, and magnetic properties, as well as the potential applications are highlighted.
Here, the structural, optical, and adsorptive behaviors of Ni0.075‐xMnxAl0.025(OH)2(CO3)0.0125·yH2O (Ni‐Mn/Al) layered double hydroxides (LDHs) are investigated to capture fluoride from aqueous ...media. The 2D mesoporous plate‐like Ni‐Mn/Al LDHs are successfully prepared via a co‐precipitation method. The molar ratio of divalent to trivalent cations is maintained at 3:1 and the pH at 10. The X‐ray diffraction (XRD) results confirm that the samples consist of pure LDH phases with a basal spacing of 7.66 to 7.72 Å, corresponding to the (003) planes at 2θ of 11.47o and the average crystallite sizes of 4.13 to 8.67 nm. The plate‐like Mn‐doped Ni‐Al LDH consists of many superimposed nanosheets with a size of 9.99 nm. Energy‐dispersive X‐ray and X‐ray photoelectron spectroscopies confirm the incorporation of Mn2+ into the Ni‐Al LDH. UV–vis diffuse reflectance spectroscopy results indicate that incorporating Mn2+ into LDH enhances its interaction with light. The experimental data from the batch fluoride adsorption studies are subjected to kinetic models such as pseudo‐first order and pseudo‐second order. The kinetics of fluoride retention on Ni‐Mn/Al LDH obey the pseudo‐second‐order model. The Temkin equation well describes the equilibrium adsorption of fluoride. The results from the thermodynamic studies also indicate that fluoride adsorption is exothermic and spontaneous.
Here, the structural, optical, and adsorptive behaviors of Ni0.075‐xMnxAl0.025(OH)2(CO3)0.0125·yH2O (Ni‐Mn/Al) layered double hydroxides (LDHs) are investigated in the context of capturing fluoride from aqueous media.
Here, the structural, optical, and adsorptive behaviors of Ni
Mn
Al
(OH)
(CO
)
·yH
O (Ni-Mn/Al) layered double hydroxides (LDHs) are investigated to capture fluoride from aqueous media. The 2D ...mesoporous plate-like Ni-Mn/Al LDHs are successfully prepared via a co-precipitation method. The molar ratio of divalent to trivalent cations is maintained at 3:1 and the pH at 10. The X-ray diffraction (XRD) results confirm that the samples consist of pure LDH phases with a basal spacing of 7.66 to 7.72 Å, corresponding to the (003) planes at 2
of 11.47
and the average crystallite sizes of 4.13 to 8.67 nm. The plate-like Mn-doped Ni-Al LDH consists of many superimposed nanosheets with a size of 9.99 nm. Energy-dispersive X-ray and X-ray photoelectron spectroscopies confirm the incorporation of Mn
into the Ni-Al LDH. UV-vis diffuse reflectance spectroscopy results indicate that incorporating Mn
into LDH enhances its interaction with light. The experimental data from the batch fluoride adsorption studies are subjected to kinetic models such as pseudo-first order and pseudo-second order. The kinetics of fluoride retention on Ni-Mn/Al LDH obey the pseudo-second-order model. The Temkin equation well describes the equilibrium adsorption of fluoride. The results from the thermodynamic studies also indicate that fluoride adsorption is exothermic and spontaneous.
The unique structural and electronic properties of 2D materials, including the metal and metal‐free ones, have prompted intense exploration in the search for new catalysts. The construction of ...different heterostructures based on 2D materials offers great opportunities for boosting the catalytic activity in electo(photo)chemical reactions. Particularly, the merits resulting from the synergism of the constituent components and the fascinating properties at the interface are tremendously interesting. This scenario has now become the state‐of‐the‐art point in the development of active catalysts for assisting energy conversion reactions including water splitting and CO2 reduction. Here, starting from the theoretical background of the fundamental concepts, the progressive developments in the design and applications of heterostructures based on 2D materials are traced. Furthermore, a personal perspective on the exploration of 2D heterostructures for further potential application in catalysis is offered.
The construction of different heterostructures based on 2D materials offers great opportunities for boosting the catalytic activity in electo(photo)chemical reactions. Starting from the theoretical background of the fundamental concepts, the progressive developments in the design and applications of heterostructures based on 2D materials are summarized.
•A novel synthesis of hierarchical MnO2 on activated carbon cloth was designed.•High-voltage asymmetric supercapacitor delivered impressive volumetric energy density.•The binder-free H-MnO2/ACC ...showed high specific capacitance and excellent cycling stability.
Despite appealing supercapacitive properties, the flexible asymmetric supercapacitor devices (FASCs) are still suffering from low mass loading and limited operating voltage, leading to unsatisfactory energy densities. Herein, we introduced a high-voltage anodic electro-deposition process (AED) which is a novel avenue enabling the synthesis of hierarchical MnO2 on activated carbon cloth (H-MnO2/ACC). Interestingly, the concomitant activation of carbon cloth substrate is found to be beneficial to improve the conductivity and hydrophilic nature of our novel electrode. A FASC based on H-MnO2/ACC-300 and reduced carbon cloth (RCC) was assembled using a mixed ionic liquid gel (ionogel) electrolyte. Benefiting from highly conductive paths derived from intimately attached fiber-MnO2 interfaces, hierarchically interpenetrated lamella MnO2 porosity and concentric MnO2 interlayer voids, as well as the merits of ionic liquid, the resultant FASC delivers an output voltage as high as 4 V and an impressive volumetric energy density of 3.82 mWh/cm3. Furthermore, the optimized H-MnO2/ACC-300 electrode with high mass loading can even retain 94.2% of initial capacitance upon 5000 cycles in 1 M Na2SO4. The unique H-MnO2/ACC can aid in the rational design towards flexible electronic devices with high mass loading and this synthetic strategy opens up enormous possibilities for the fabrication of electrodeposited materials.
Two-dimensional layered materials (2DLMs) have attracted a tremendous amount of attention as photodetectors due to their fascinating features, including high potentials in new-generation electronic ...devices, wide coverage of bandgaps, ability to construct van der Waals heterostructures, extraordinary light-mass interaction, strong mechanical flexibility, and the capability of enabling synthesis of 2D nonlayered materials. Until now, most attention has been focused on the well-known graphene and transition metal dichalcogenides (TMDs). However, a growing number of functional materials (more than 5619) with novel optoelectronic and electronic properties are being re-discovered, thereby widening the horizon of 2D libraries. In addition to showing common features of 2DLMs, these new 2D members may bring new opportunities to their well-known analogues, like wider bandgap coverage, direct bandgaps independence with thickness, higher mechanical flexibility, and new photoresponse phenomena. The impressive results communicated so far testify that they have shown high potentials with photodetections covering THz, IR, visible, and UV ranges with comparable or even higher performances than well-known TMDs. Here, we give a comprehensive review on the state-of-the-art photodetections of two-dimensional materials beyond graphene and TMDs. The review is organized as follows: fundamentals of photoresponse first are discussed, followed by detailed photodetections of new 2D members including both layered and non-layered ones. After that, photodiodes and hybrid structures based on these new 2D materials are summarized. Then, the integration of these 2D materials with flexible substrates is reviewed. Finally, we conclude with the current research status of this area and offer our perspectives on future developments. We hope that, through reading this manuscript, readers will quickly have a comprehensive view on this research area.
Two-dimensional materials beyond graphene and TMDs can be promising candidates for wide-spectra photodetection.
Transition metal phosphorus trichalcogenides (MPX3, X = S, Se) are layered materials possessing high chemical diversity and wide range of applications in a broad wave length spectrum. Theoretical ...studies reveal that auspicious activity of photocatalytic water splitting can be realized from them. However, experimental efforts have so far been challenged with the synthesis bottleneck. Described herein is the general chemical vapor deposition (CVD) growth method and photocatalytic activity of these materials. A novel route to systematically grow MnPX3 nanosheets on flexible carbon fiber substrate is reported. The temperature profile of the CVD process is carefully optimized that confer a facile and successful conversion of oxide precursor to phospho‐trichalcogenide with high crystallinity. Moreover, the obtained manganese‐based phosphorus trichalcogenide nanosheets demonstrate promising activity in sacrificial agent‐free photocatalytic water splitting under simulated solar light (AM 1.5G). This study provides a significant stepping stone in exploring the fascinating world of functional 2D materials and pursuing performance enhancement.
High crystal quality manganese‐based transition metal phosphorus trichalcogenide nanosheets are synthesized facilely through chemical vapor deposition method. This novel route results in a successful synthesis of monoclinic MnPS3 and hexagonal MnPSe3 nanosheets with high phase purity. The obtained materials demonstrate promising photocatalytic activity of water splitting in pure water without cocatalyst.
2D layered transition metal phosphorus trichalcogenides (MPX3) possess higher in‐plane stiffness and lower cleavage energies than graphite. This allows them to be exfoliated down to the atomic ...thickness. However, a rational exfoliation route has to be sought to achieve surface‐active and uniform individual layers. Herein, monolayered FePS3 quantum sheets (QSs) are systematically obtained, whose diameters range from 4–8 nm, through exfoliation of the bulk in hydrazine solution. These QSs exhibit a widened bandgap of 2.18 eV as compared to the bulk (1.60 eV) FePS3. Benefitting from the monolayer feature, FePS3 QSs demonstrate a substantially accelerated photocatalytic H2 generation rate, which is up to three times higher than the bulk counterpart. This study presents a facile way, for the first time, of producing uniform monolayer FePS3 QSs and opens up new avenues for designing other low‐dimensional materials based on MPX3.
A facile way to produce monolayer FePS3 quantum sheets from the bulk is developed. The quantum sheets demonstrate a lateral size of 4–8 nm and exhibit a widened bandgap of 2.18 eV. Significantly, they also show superior hydrogen generation with the rate of 290 µmol h−1 g−1, three times higher than the bulk.
PDF
