Uniform hollow spheres of Cu 2 O and CuS were successfully synthesized by chemical transformation of in situ formed sacrificial templates containing Cu(I) in aqueous solutions. The shell thickness of these hollow spheres can be adjusted through the choice of the bromide source used for the formation of intermediate templates. Specifically, thick-shell hollow spheres (about 130-180 nm in shell thickness) were obtained by using CuBr solid spheres as the templates, which were formed by the reduction of CuBr 2 with ascorbic acid; on the other hand, thin-shell hollow spheres (about 20-25 nm in shell thickness) were obtained by using spherical aggregates consisting of the Cu + , Br -, and (C 4 H 9 ) 4 N + ions as the templates, which were formed by the reduction of CuCl 2 with ascorbic acid in the presence of (C 4 H 9 ) 4 NBr. In both cases, crystalline Cu 2 O hollow spheres were directly obtained at room temperature, while amorphous Cu 2 S hollow spheres were first obtained at room temperature and transformed into wellcrystallized CuS hollow spheres after a hydrothermal treatment at 160 °C. The optical limiting properties of the thin-shell hollow spheres of Cu 2 O and CuS were characterized by using nanosecond laser pulses. Strong optical limiting responses were detected for both the Cu 2 O and CuS hollow spheres, which make these semiconductor hollow spheres promising materials for applications in the protection of human eyes or optical sensors from high-power laser irradiation.

Hierarchical, two‐dimensional (2D), disc‐like networks consisting of crossed single‐crystalline Bi2S3 nanorods have been synthesized via a novel 2D‐template‐engaged topotactic transformation process, which involves the formation of intermediate BiOCl single‐crystalline discs and their subsequent chemical transformation into disc‐like Bi2S3 nanofabrics. The transformation process from (001)‐oriented BiOCl discs to disc‐like Bi2S3 nanorod networks has been followed by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron diffraction (ED) and X‐ray diffraction (XRD), which revealed that the close matching between the lattice constants of the c‐axis for orthorhombic Bi2S3 and the a‐ or b‐axis for tetragonal BiOCl could be responsible for the preferential growth of [001]‐oriented Bi2S3 nanorods on the top faces of (001)‐oriented BiOCl discs along the two perpendicular [100] and [010] directions of BiOCl. The diameter of the Bi2S3 nanorods involved in the networks can be adjusted by changing the bismuth ion concentration in the reaction solution; moreover, an increase of the HCl concentration would prevent the formation of precursor BiOCl discs, leading to the formation of Bi2S3 nanostructures with varied morphologies. Charge–discharge curves and cyclic voltammograms of the obtained Bi2S3 nanostructures were measured to investigate their electrochemical hydrogen storage behaviors. It was found that the disc‐like Bi2S3 nanorod networks could electrochemically charge and discharge with a capacity of 162 mA h g−1 at room temperature, indicating their potential applications in hydrogen storage, high‐energy batteries, and catalytic fields.

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