Colloidal nanocrystals (NCs) of metal halide perovskite have recently aroused great research interest, due to their remarkable optical and electronic properties. We report a solution synthesis of a new member in this category, that is, all-inorganic lead-free cesium germanium iodine (CsGeI ) perovskite NCs. These CsGeI colloidal NCs are confirmed to adopt a rhombohedral structure. Moreover, the electron beam-induced transformations of these lead-free perovskite NCs have been investigated for the first time. The fracture of single-crystalline CsGeI nanocubes occurs first, followed by the emergence and growth of cesium iodine (CsI) single crystals and the final fragmentation into small debris with random orientations. Notably, the electron-reduced Ge species in CsGeI nanocubes exhibit a distinctive transformation path, compared to heavier Pb atoms in lead halide perovskite NCs.

Ultrathin metal-organic framework (MOF) nanosheets possessing inherent advantages of both two-dimensional (2D) features and MOFs are attracting intensive research interest. The direct manufacture of MOF nanosheets is still a challenge up to now. Here, we have developed a novel bottom-up approach to synthesize zeolitic imidazolate framework-67 (ZIF-67) nanosheets, which can be in situ converted into CoO ultrathin nanomeshes after thermal treatment. Interestingly, the obtained CoO nanomeshes are rich in oxygen defects, providing fruitful active sites for the faradaic reaction. The modified electrode exhibits a large specific capacitance (1216.4 F g at 1 A g), as well as a high rate capability (925.5 F g at 20 A g). Moreover, an asymmetric supercapacitor made of CoO//activated carbon shows an energy density of 46.5 Wh kg at 790.7 W kg. Furthermore, the 2D CoO ultrathin nanomeshes show an outstanding performance for the oxygen evolution reaction with an overpotential of 230 mV at the onset potential and a small Tafel slope of 74.0 mV dec. The present method presents a facile avenue to the preparation of other 2D ultrathin metal oxide nanostructures with various applications in energy catalysis and conversion.

Intractable hurdles of low Coulombic efficiency and dendritic Li formation during a repeated deposition/stripping process hinder the commercial use of  Li metal anode for next-generation battery systems. Achieving uniform Li nucleation is one of the effective strategies to address these issues, and it is of practical importance to realize this on a commercial Cu current collector that is lithiophobic. Herein, we design a nanostructured Ag lithiophilic layer on a Cu foil via an electroless plating process for a Li metal current collector. The deposition of lithiophilic Ag particles that are homogeneously distributed on the Cu foil can reduce the nucleation overpotential, realizing uniform Li nucleation and subsequently flat Li plating. As a result, a stable cycle stability of up to 360 h (1 mA cm–2) and an average Columbic efficiency of 94.5% for 100 cycles (1 mA cm–2) are achieved. Furthermore, CuAg full cells with LiFePO4 as a cathode exhibit good cycle performances and low polarization voltage. This approach provides another facile way for a stable lithium metal anode.

The hierarchical CuCoO@carbon quantum dots (CQDs) hollow microspheres constructed by 1D porous nanowires have been successfully prepared through a simple CQDs-induced hydrothermal self-assembly technique. XPS analysis shows the CuCoO@CQDs possesses the Co(II)-rich surface associated with the oxygen vacancies, which can effectively boost the Faradaic reactions and oxygen evolution reaction (OER) activity. For example, the as-synthesized 3D porous CuCoO@CQDs electrode exhibits high activity toward overall electrochemical water splitting, for example, an overpotential of 290 mV for OER and 331 mV for hydrogen evolution reaction (HER) in alkaline media have been achieved at 10 mA cm, respectively. Furthermore, an asymmetric supercapacitor (ASC) (CuCoO@CQDs//CNTs) delivers a high energy density of 45.9 Wh kg at 763.4 W kg, as well as good cycling ability. The synergy of Co(II)-rich surface, oxygen vacancies, and well-defined 3D hollow structures facilitates the subsequent surface electrochemical reactions. This work presents a facile method to fabricate energetic nanocomposites with highly reactive, durable, and universal functionalities.

Engineering novel Sn‐based bimetallic materials could provide intriguing catalytic properties to boost the electrochemical CO2 reduction. Herein, the first synthesis of homogeneous Sn1−xBix alloy nanoparticles (x up to 0.20) with native Bi‐doped amorphous SnOx shells for efficient CO2 reduction is reported. The Bi‐SnOx nanoshells boost the production of formate with high Faradaic efficiencies (>90%) over a wide potential window (−0.67 to −0.92 V vs RHE) with low overpotentials, outperforming current tin oxide catalysts. The state‐of‐the‐art Bi‐SnOx nanoshells derived from Sn0.80Bi0.20 alloy nanoparticles exhibit a great partial current density of 74.6 mA cm−2 and high Faradaic efficiency of 95.8%. The detailed electrocatalytic analyses and corresponding density functional theory calculations simultaneously reveal that the incorporation of Bi atoms into Sn species facilitates formate production by suppressing the formation of H2 and CO.