Water electrolysis is viewed as a key technology in producing environmentally friendly hydrogen to combat fossil fuel shortage and work towards carbon neutrality by 2050. Despite its potential, large-scale commercialization faces hurdles due to the need for highly active and stable electrocatalysts under harsh operational conditions. Research has shifted towards understanding reconstruction mechanisms of catalysts to improve efficiency and stability, particularly for the hydrogen evolution reaction (HER). A recent study synthesized high-purity hexagonal Co2Mo3O8 nanoparticles and explored their behavior in water splitting. The study revealed that the surface structure transformation of Co2Mo3O8 in a potassium hydroxide solution could be controlled by applied potentials, leading to the formation of an electrochemically stable Co(OH)2@Co2Mo3O8 heterostructure. This reconstruction process, involving the etching of Mo from the precatalyst into the electrolyte, ultimately enhanced catalytic activity and stability. By manipulating biases, a high amount of Co(OH)2 on Co2Mo3O8 was achieved, showing promising results for efficient hydrogen production. This innovative approach sheds light on potential strategies to advance catalyst design and improve hydrogen evolution efficiency.