A combination of high surface area, fast-speed charge transportation, excellent intrinsic activity, and low material cost is desired for electrocatalysts' applications, such as hydrogen production, counter electrodes of electrochemical solar cells, etc. In this regard, we originally develop a vertically aligned Co-doped MoS2 nanosheet array via a facile chemical vapour deposition (CVD) approach that utilizes the reaction between drop-coated CoCl2-MoCl5 precursor film and sulfur vapour released from elemental sulfur powder. Such structure that exposes primarily edge sites of the nanosheets provides reaction with more active centers and guarantees that electrons transport almost along high-electron-mobility basal plane of MoS2. Simultaneously, the catalytic activity of the in-plane S atoms of MoS2, exposing at the splits of MoS2 nanosheets, can be triggered via Co atom-doping. Such an array that is in-situ grown on graphite foil substrate performs as an efficient electrocatalyst for hydrogen evolution reaction with an overpotential of 185 mV at a current density of 10 mA.cm(-2) and an extremely high TOF 0.56 s(-1) at 200 mV over-potential, meanwhile, sponsoring as a counter electrode for efficient (8.99%) dye-sensitized solar cells. (C) 2019 Elsevier Inc. All rights reserved.