Room‐temperature‐operating highly sensitive mid‐wavelength infrared (MWIR) photodetectors are utilized in a large number of important applications, including night vision, communications, and optical radar. Many previous studies have demonstrated uncooled MWIR photodetectors using 2D narrow‐bandgap semiconductors. To date, most of these works have utilized atomically thin flakes, simple van der Waals (vdW) heterostructures, or atomically thin p–n junctions as absorbers, which have difficulty in meeting the requirements for state‐of‐the‐art MWIR photodetectors with a blackbody response. Here, a fully depleted self‐aligned MoS2‐BP‐MoS2 vdW heterostructure sandwiched between two electrodes is reported. This new type of photodetector exhibits competitive performance, including a high blackbody peak photoresponsivity up to 0.77 A W−1 and low noise‐equivalent power of 2.0 × 10−14 W Hz−1/2, in the MWIR region. A peak specific detectivity of 8.61 × 1010 cm Hz1/2 W−1 under blackbody radiation is achieved at room temperature in the MWIR region. Importantly, the effective detection range of the device is twice that of state‐of‐the‐art MWIR photodetectors. Furthermore, the device presents an ultrafast response of ≈4 µs both in the visible and short‐wavelength infrared bands. These results provide an ideal platform for realizing broadband and highly sensitive room‐temperature MWIR photodetectors.

Reaction of L(0)NiBr(2) with 2 equiv of NaH yielded the Ni(II) hydride complex [(L(•-))Ni(μ-H)(2)Ni(L(•-))] (1) (L = [(2,6-iPr(2)C(6)H(3))NC(Me)](2); L(0) represents the neutral ligand, L(•-) is its radical-anionic form, and L(2-) denotes the dianion) in good yield. Stepwise reduction of complex 1 led to a series of nickel hydrides. Reduction of 1 with 1 equiv of sodium metal afforded a singly reduced species [Na(DME)(3)][(L(•-))Ni(μ-H)(2)Ni(L(•-))] (2a) (DME = 1,2-dimethoxyethane), which contains a mixed-valent core [Ni(μ-H)(2)Ni](+). With 2 equiv of Na a doubly reduced species [Na(DME)](2)[L(2-)Ni(μ-H)(2)NiL(2-)] (3a) was obtained, in which each monoanion (L(•-)) in the precursor 1 has been reduced to L(2-). By using potassium as the reducing agent, two analogous species [K(DME)(4)][(L(•-))Ni(μ-H)(2)Ni(L(•-))] (2b) and [K(DME)](2)[L(2-)Ni(μ-H)(2)NiL(2-)] (3b) were obtained. Further treatment of 3b with 2 equiv of K led to a trinuclear complex [K(DME)(THF)](2)K(2)[L(2-)Ni(μ-H)(2)Ni(μ-H)(2)NiL(2-)] (4), which contains one Ni(II) and two Ni(I) centers with a triplet ground state. When 1 and 3a were warmed in toluene or benzene, respectively, three reverse-sandwich dinickel complexes, [(L(•-))Ni(μ-η(3):η(3)-C(7)H(8))Ni(L(•-))] (5) and [Na(DME)](2)[L(2-)Ni(μ-η(3):η(3)-C(6)H(5)R)NiL(2-)] (6: R = CH(3); 7: R = H), were isolated. Reaction of 1 with Me(3)SiN(3) gave the N(3)-bridged complex [(L(•-))Ni(μ-η(1)-N(3))(2)Ni(L(•-))] (8). The crystal structures of complexes 1-8 have been determined by X-ray diffraction, and their electronic structures have been fully studied by EPR/NMR spectroscopy.

Metal phosphorous tri-chalcogenides are a category of new ternary 2D layered materials with a wide range of tuneable bandgaps (1.2-3.5 eV). These wide-bandgap semiconductors exhibit great potential applications in solar-blind ultraviolet (SBUV) photodetection. However, these 2D solarblind photodetectors suffer from low photoresponsivity, slow photoresponse speed, and narrow operation spectral region, thereby limiting their practical applications. Here, an ultra-broadband photodetection based on a FePSe 3 / MoS 2 heterostructure with coverage ranging from solar-blind ultraviolet 265 nm to longwave infrared (LWIR) 10.6 µm is reported. Notably, the device exhibits excellent weak light detection capability. A high photoresponsivity of 33 600 A W −1 and an external quantum efficiency of 1.57 × 10 7 % are demonstrated. A noise-equivalent power as low as 5.7 × 10 -16 W Hz −1/2 and a specific detectivity up to 1.51 × 10 13 cm Hz 1/2 W −1 are realized in the SBUV region. The room temperature LWIR photoresponsivity of 0.12 A W −1 is realized. This work opens a route to design high-performance SBUV photo detectors and wide spectral photoresponse applications.

PAN/Ag 3 PO 4 core-shell hetero-nanofibers have been fabricated for the first time by combining electrospinning technology with ion exchange reaction, which exhibit much higher visible light driven photocatalytic activities for the degradation of organic contaminants than pure Ag 3 PO 4 nanoparticles.One-dimensional (1D) nanostructures have received extensive attention owing to their potential applications in photoconductors, electron eld emitters, and solar cells in the past decade. 1-4 Recently, the rational design and synthesis of polymer-inorganic 1D nanohybrids have become of particular interest because of their novel multifunctional physical and chemical properties as well as their potential advantages in photonics, electronics, catalysis and magnetism. Compared with other fabrication methods, electrospinning offers a relatively simple and versatile method to generate such 1D nanostructures with controlled morphology and composition. Up to now, many inorganic nanoparticles such as pure metal, metal oxides and metal suldes have been incorporated to various polymer matrices by combining the electrospinning technique with other strategies, such as direct-dispersion, 5 in situ photoreduction, 6 gas-solid reaction, 7 and sol-gel method. 8 However, note that some limitations still remain in the present two-step approaches, including the uncontrollable arrangement between polymer and inorganic phases, the incomplete coating, and limitations of the hetero-product species. Thus, the exploration of a general and efficient method for the generation of the polymer-inorganic composite nanobers with well dispersed inorganic nanoparticles on the polymer matrix is still a great challenge.Compared with other materials, Ag 3 PO 4 has recently attracted particular attention owing to its excellent photooxidative capabilities for O 2 evolution from water as well as organic dye decomposition under visible light irradiation. 9 However, the present efforts mostly focus on the fabrication of inorganic/ Ag 3 PO 4 hetero-structures, including etc. Moreover, the as-prepared hetero-structures were generally obtained by randomly combining inorganics with Ag 3 PO 4 , which mostly possessed of uncontrollable combinations and irregular structures. Thereby, the rational design and fabrication of well-dened polymer-Ag 3 PO 4 composite nanobers may greatly improve their current photochemical reactivity and open up new applications.Herein, we demonstrated an interesting and simple strategy by combining electrospinning technology with ion exchange reaction for preparing uniform polyacrylonitrile (PAN)/Ag 3 PO 4 core-shell hetero-nanobers. Furthermore, the compositions, structures, and morphologies of the hybrid nanobers could be rationally tailored by simply adjusting the synthetic parameters. Moreover, the studies of photocatalytic performance have clearly revealed that the as-prepared PAN/Ag 3 PO 4 core-shell nanobers exhibited superior photocatalytic properties for the degradation of organic contaminants than pure Ag 3 PO 4 nanoparti...

Two alkali metal complexes of a bridging 2,5-diamino-1,4-benzoquinonediimine ligand (dipp-dabqdiH(2)), [(thf)(2)Li(μ-dipp-dabqdi)Li(thf)(2)] (1) and [(dme)(1.5)Na(μ-dipp-dabqdi)Na(dme)(1.5)](n) (2, dme = 1,2-dimethoxyethane), have been synthesized by the reaction of dipp-dabqdiH(2) with Li(n)Bu or sodium metal. In addition, treatment of 1,2,4,5-tetrakis(2,6-diisopropylamino)benzene (dipp-tabH(4)) with potassium metal in dme afforded the complex [(dme)(2)K(μ-dipp-tabH(2))K(dme)(2)] (3). X-ray crystal diffraction analyses revealed that complexes 1 and 3 have dinuclear structures, while the sodium complex 2 aggregates to a one-dimensional polymer through bridging dme ligands. With increasing ion radius, the coordination number of the alkali metal (Li, Na, and K) increases from four to five to six, while the coordination geometry changes from distorted tetrahedral to square pyramidal and further to octahedral in 1, 2, and 3, respectively. The salt metathesis reactions of 1 and 2 with anhydrous ZnCl(2) yielded the ion-contacted zinc complexes [(thf)(3)Li(μ-Cl)ClZn(μ-dipp-dabqdi)ZnCl(μ-Cl)Li(thf)(3)] (4), [(dme)(2)Li(μ-Cl)ClZn(μ-dippdabqdi)ZnCl(μ-Cl)Li(dme)(2)] (5), and [(dme)(2)Na(μ-Cl)(2)Zn(μ-dipp-dabqdi)Zn(μ-Cl)(2)Na(dme)(2)] (6), respectively. The ligand exists as the dianionic form in compounds 1-6 upon double deprotonation, and a complete electronic delocalization (except for 3) of the quinonoid π-system is observed between the metal centers over the two N═C-C═C-N halves of the ligand. The electronic structures of the complexes were studied by density functional theory (DFT) computations.

In recent decades, solar-driven hydrogen production over semiconductors has attracted tremendous interest owing to the global energy and environmental crisis. Among various semiconductor materials, TiO2 exhibits outstanding photocatalytic properties and has been extensively applied in diverse photocatalytic and photoelectric systems. However, two major drawbacks limit practical applications, namely, high charge-recombination rate and poor visible-light utilization. In this work, heterostructured TiO2 nanotube arrays grafted with Cr-doped SrTiO3 nanocubes were fabricated by simply controlling the kinetics of hydrothermal reactions. It was found that coupling TiO2 nanotube arrays with regular SrTiO3 nanocubes can significantly improve the charge separation. Meanwhile, doping Cr cations into SrTiO3 nanocubes proved to be an effective and feasible approach to enhance remarkably the visible-light response, which was also confirmed by theoretical calculations. As a result, the rate of photoelectrochemical hydrogen evolution of these novel heteronanostructures is an order of magnitude larger than those of TiO2 nanotube arrays and other previously reported SrTiO3 /TiO2 nanocomposites under visible-light irradiation. Furthermore, the as-prepared Cr-doped SrTiO3 /TiO2 heterostructures exhibit excellent durability and stability, which are favorable for practical hydrogen production and photoelectric nanodevices.

No abstract

The reactions of dialumane [L(thf)Al-Al(thf)L] (1, L=[{(2,6-iPr2C6H3)NC(Me)}2](2-)) with stilbene and styrene afforded the oxidation/insertion products [L(thf)Al(CH(Ph)-CH(Ph))AlL] (2) and [L(thf)Al(CH(Ph)-CH2)Al(thf)L] (3), respectively. In the presence of Na metal, precursor 1 reacted with butadienes, possibly through the reduced "dialumene" or the "carbene-like" :AlL species, to yield aluminacyclopentenes [LAl(CH2C(Me)=C(Me)CH2)Na]n (4 a) and [Na(dme)3][LAl(CH2C(Me)=CHCH2)] (4 b, dme=dimethoxyethane) as [1+4] cycloaddition products, as well as the [2+4] cycloaddition product 1,6-dialumina-3,8-cyclodecadiene, [{Na(dme)}2][LAl(CH2C(Me)=C(Me)CH2)2AlL] (5). The possible mechanisms of the cycloaddition reactions were studied by using DFT computations.