Molybdenum and tungsten disulfides-based nanocomposite films for energy storage and conversion: A review

Two-dimensional (2D) transition metal disulfides (TMDSs) have triggered worldwide research interest due to their weak interlayer van der Waals (vdW) interaction, low cost, chemical/thermal stability and excellent processability. Among them, MoS2 and WS2 are two typical chemicals widely investigated. Yet their individual poor conductivity and restacking property require combination with other conductive materials, like carbonaceous matrices, to obtain better performance in energy storage and conversion devices. The current state-of-the-art and the progress made over the past five years on the development of XS2-based composite films (X = Mo, W), many of which are self-standing and additive-free, is summarized here. The pivotal role of such films in batteries, supercapacitors and hydrogen production is highlighted. The challenges and opportunities for the future exploration of these 2D layered hybrids are also put forward and discussed.