In a method and device for conversion of water into hydrogen peroxide (H2O2), a corona discharge zone is generated between a first electrode (10) and a second electrode (6) one of which is insulated and another of which is not insulated and wherein a respective surface of each of the electrodes face one another. The first electrode (10) is rotated so as to induce relative rotation between the first electrode and the second electrode； and liquid water is conveyed on to a surface of the first electrode facing the second electrode close to the axis of rotation (4) of the first electrode whereby the liquid water advances outward through the corona discharge zone towards a periphery of the first electrode under the action of centrifugal force caused by rotation of the first electrode.
