With NaBH4 as the assistant reductant, small and highly dispersed Pt nanoparticles are formed on E-MoS2 nanosheets which provide abundant catalytically active sites and exhibit excellent hydrogen evolution reaction (HER) performance.

Two-dimensional transition-metal dichalcogenides are affordable alternatives to noble metal catalysts for hydrogen evolution reaction (HER). Here, we report a facile one-step solvothermal method to synthesize the 1T MoS2 hierarchical nanosphere (NSP) that can function as an efficient and stable electrocatalyst for HER using an environment-friendly solvent without the assistance of a template or additive. The reaction solvent is found to play a vital role in regulating the morphology and phase of the resultant MoS2. A haystack of 2H MoS2 nanosheets is obtained when water is used as the solvent, and the 1T MoS2 NSP is attained when ethanol is used. The 1T MoS2 NSP has a three-dimensional hierarchical structure and good conductivity, which lead to the excellent electrocatalytic HER performance in an acid solution with its overpotential lower than the reported MoS2-based electrocatalysts. It also demonstrates exceptional electrochemical stability, showing little variation in overpotential for 5000 reaction cycles.

Self-driven photodetectors are essential for many applications where it is unpractical to provide or replace power sources. Here, we report a new device architecture for self-driven photodetectors with tunable asymmetric Schottky junctions based on a nanomesh electrode. The vertical-channel nanomesh scaffold is composed of a hexagonally ordered nanoelectrode array fabricated via the nanosphere lithography technique. The top and bottom nanoelectrodes are separated by only 30 nm and the areal ratio of the two nanoelectrodes can be fine-tuned, which effectively modifies the geometric asymmetricity of the Schottky junctions in the photodetector devices. The self-driven photodetectors are fabricated by depositing the (FAPbI3)0.97(MAPbBr3)0.03 (MA = methylammonium, FA = formamidinium) perovskite films onto the nanomesh electrodes. Under the self-driven mode, the optimized device demonstrates a high detectivity of 1.05 × 1011 Jones and a large on/off ratio of 2.1 × 103. This nanomesh electrode is very versatile and can be employed to investigate the optoelectronic properties of various semiconducting materials.

Anodic aluminum oxide (AAO) templates are widely used for the development of various functional nanomaterials due to their highly ordered and tunable porous structures. Here, we report a new hierarchical AAO (hAAO) template with the hexagonally ordered unit cells and the radially distributed nanochannels. It is formed by integrating the self-assembled polystyrene microsphere template into the AAO fabrication process and rationalized in terms of mechanical stress and electric-field-induced oxide dissolution. The back side of the hAAO template resembles a moth-eye-like nanoarray, which shows good hydrophobicity. A variety of radial nanopillar arrays and moth-eye-like nanoarrays are fabricated by a series of materials and synthesis techniques employing the hAAO template. These unique nanoarrays demonstrate many physicochemical properties that are distinct from those obtained from the conventional AAO template.