Electrochemical catalytic reactions are now playing an important role in current chemical industry,among them the electrochemical gas evolution reactions are the most attractive topic.Here we review some recent progresses in our laboratory related to the hydrothermal synthesis of metal oxides/hydroxides and metal chalcogenides nanoarrays,whose structures are designed aiming to the application of electrochemical catalysts besides pseudocapacitor.After careful measurements,we found that constructing the nanoarray architecture could bring about a boost improvement of the catalyst,which was attributed to the tight connection to the substrate and accelerating the electron/electrolyte penetration.[1-4] More importantly,the surface morphology can reduce the adhesion to the as-formed gas bubbles and thus promote gas releasing process,which was demonstrated in MoS2 case.[5] These developments clearly demonstrate the benefits of nano-array architecture and guide the optimal structural design for future energy related process.