Tungsten diselenide (WSe₂) film was obtained by rapid selenization of magnetron sputtered tungsten (W) film. To prevent WSe₂ film peeling off from the substrate during selenization, the W film was designed with a double-layer structure. The first layer was deposited at a high sputtering-gas pressure to form a loose structure, which can act as a buffer layer to release stresses caused by WSe₂ growth. The second layer was deposited naturally on the first layer to react with selenium vapour in the next step. The effect of the W film deposition parameters(such as sputtering time, sputtering-gas pressure and substrate bias voltage)on the texture and surface morphology of the WSe₂ film was studied. Shortening the sputtering time, increasing the sputtering-gas pressure or decreasing the substrate bias voltage can help synthesize WSe₂ films with more platelets embedded vertically in the matrix. The stress state of the W film influences the WSe₂ film texture. Based on the stress state of the W film, a model for growth of the WSe₂ films with different textures was proposed. The insertion direction of the van der Waals gap is a key factor for the anisotropic formation of WSe₂ film.

Nanocomposites of reduced graphene oxide (RGO) sheets decorated with amorphous ruthenium oxide nanoparticles are fabricated through a one-pot hydrothermal process without additional dispersants. During the hydrothermal reduction, unilamellar graphene sheets with curved and veil-like morphology are formed and multilamellar graphene sheets are further separated by amorphous RuO₂·xH₂O with a particle size of 3–8 nm. The nanocomposites exhibit evident pseudo capacitance behavior and the comprehensive electrochemical performance is improved markedly compared with that of the single components. When the precursor ratio of graphene oxide (GO) to RuCl₃·xH₂O is 2 : 10, the graphene–RuO₂ (GR) nanocomposite electrode achieves the highest specific capacitance of 542.5 F g⁻¹ and the minimum ESR value of 1.21 Ω at 0.1 A g⁻¹, retaining 94% after 1000 cycles at 1 A g⁻¹. Thus graphene sheets/ruthenium oxide nanocomposites bode well for a promising candidate in supercapacitor technology.