One-dimensional (1D) metal-oxide nanostructures are ideal systems for exploring a large number of novel phenomena at the nanoscale and investigating size and dimensionality dependence of nanostructure properties for potential applications. The construction and integration of photodetectors or optical switches based on such nanostructures with tailored geometries have rapidly advanced in recent years. Active 1D nanostructure photodetector elements can be configured either as resistors whose conductions are altered by a charge-transfer process or as field-effect transistors (FET) whose properties can be controlled by applying appropriate potentials onto the gates. Functionalizing the structure surfaces offers another avenue for expanding the sensor capabilities. This article provides a comprehensive review on the state-of-the-art research activities in the photodetector field. It mainly focuses on the metal oxide 1D nanostructures such as ZnO, SnO2, Cu2O, Ga2O3, Fe2O3, In2O3, CdO, CeO2, and their photoresponses. The review begins with a survey of quasi 1D metal-oxide semiconductor nanostructures and the photodetector principle, then shows the recent progresses on several kinds of important metal-oxide nanostructures and their photoresponses and briefly presents some additional prospective metal-oxide 1D nanomaterials. Finally, the review is concluded with some perspectives and outlook on the future developments in this area.

The synthesis of high-quality In2Se3 nanowire arrays via thermal evaporation method and the photoconductive characteristics of In2Se3 individual nanowires are first investigated. The electrical characterization of a single In2Se3 nanowire verifies an intrinsic n-type semiconductor behavior. These single-crystalline In2Se3 nanowires are then assembled in visible-light sensors which demonstrate a fast, reversible, and stable response. The high photosensitivity and quick photoresponse are attributed to the superior single-crystal quality and large surface-to-volume ratio resulting in fewer recombination barriers in nanostructures. These excellent performances clearly demonstrate the possibility of using In2Se3 nanowires in next-generation sensors and detectors for commercial, military, and space applications.

Abstract3D‐networked, ultrathin, and porous Ni3S2/CoNi2S4 on Ni foam (NF) is successfully designed and synthesized by a simple sulfidation process from 3D Ni–Co precursors. Interestingly, the edge site‐enriched Ni3S2/CoNi2S4/NF 3D‐network is realized by the etching‐like effect of S2− ions, which made the surfaces of Ni3S2/CoNi2S4/NF with a ridge‐like feature. The intriguing structural/compositional/componental advantages endow 3D‐networked‐free‐standing Ni3S2/CoNi2S4/NF electrodes better electrochemical performance with specific capacitance of 2435 F g−1 at a current density of 2 A g−1 and an excellent rate capability of 80% at 20 A g−1. The corresponding asymmetric supercapacitor achieves a high energy density of 40.0 W h kg−1 at an superhigh power density of 17.3 kW kg−1, excellent specific capacitance (175 F g−1 at 1A g−1), and electrochemical cycling stability (92.8% retention after 6000 cycles) with Ni3S2/CoNi2S4/NF as the positive electrode and activated carbon/NF as the negative electrode. Moreover, the temperature dependences of cyclic voltammetry curve polarization and specific capacitances are carefully investigated, and become more obvious and higher, respectively, with the increase of test temperature. These can be attributed to the components' synergetic effect assuring rich redox reactions, high conductivity as well as highly porous but robust architectures. This work provides a general, low‐cost route to produce high performance electrode materials for portable supercapacitor applications on a large scale.

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time further and enhance power density during acceleration process so as to perfect its practicality. [1b,3] Electrode materials (cathode and anode) play an important role in the electrochemical properties of LIBs, including energy-density, cycle-life, rate capability, and safety among others. Graphite materials with high capacity greater than 300 mAh g −1 , superior structural stability, as well as low cost are significantly applied as anode electrode in commercialized LIBs. [4] The other anode, graphite/silicon composites that can deliver higher capacity of around 1000 mAh g −1 and that of pure graphite electrode are gradually commercialized to further enhance the energy density of LIBs. [5] The first commercial cathode material, layered oxide LiCoO 2 with O3 structure (in which oxygen anion have a cubic close packing arrangement in the form of ABCABC…), illustrates the unpleasant transformation from hexagonal phase to monoclinic phase, particularly when the Li + deintercalation ratio (x) exceeds 0.5 in Li 1−x CoO 2 . [6] This is in contrast with graphite-based anode with preferred electrochemical performance and low cost. Also, this phase transition derived from the order/disorder transformation of Li + is anticipated to cause rapid decay of reversible capacity. [6d] Consequently, the LiCoO 2 cathode can only deliver around 150 mAh g −1 , which has limi ted the performance promotion of LIBs and the far-ranging applications of LIBs in PHEVs and EVs.Additionally, developing high-capacity (energy-density) cathode materials with desired electrochemical behaviors in place of the conventional LiCoO 2 has been the main motivation behind LIBs in the recent past. Three main groups of cathode materials, layered oxides including lithium-stoichiometric Li[Ni x Co y Mn 1−x−y ]O 2 and lithium-rich Li 1+z M 1−z O 2 (M = Mn, Ni, Co, Ru, Sn, Ir, etc.), spinel LiM 2 O 4 (M = Ni, Mn), together with olive LiMXO 4 (M = Fe, Mn, Co; X = P, Si) as illustrated in Figure 1, are broadly examined as the next-generation cathode materials for LIBs. [3a,6e,7] Among these candidates lithiumrich and manganese-based layered oxides display the highest energy-density of approach 1000 Wh Kg −1 as a result of the large reversible capacity of ≈300 mAh g −1 and high voltage of 3.5 V (vs. Li/Li + ). However, there are various significantThe urgent prerequisites of high energy-density and superior electrochemical properties have been the main inspiration for the advancement of cathode materials in lithium-ion batteries (LIBs) in the last two decades. Nickel-rich layered transition-metal oxides with large reversible capacity as well as high operating voltage are considered as the most promising candidate for next-generation LIBs. Nonetheless, the poor long-term cycle-life and inferior thermal stability have limited their broadly practical applications. In the research of LIBs, it is observed that surface/interfacial structure and chemistry play significant roles in the performance of cathode cycling. This is due to the fact that they are basical...