WO3@ZnO Nanoarrays as the Photoanode for Photoelectrochemical Production of H2O2

WO 3 @ZnO core–shell nanoarrays with a Z-scheme heterojunction structure have been fabricated by combining electrodeposition and dropping process and used as photoanodes for the production of hydrogen peroxide (H 2 O 2 ). The photocurrent density of the WO 3 @ZnO nanoarray photoanode is 1.57 mA∙cm −2 at the applied potential of 1.8 V vs reversible hydrogen electrode, which exhibits almost 4 time larger than that of pure ZnO nanoarray photoanode. A high photoconversion efficiency to the production of H 2 O 2 (0.53%) and Faradic efficiency (33%) are also reached by this WO 3 @ZnO nanoarray photoanode under Air-Mass 1.5 Global (AM 1.5 G, 100 mW∙cm −2 ). This work provides an effective approach for the application of Z-scheme heterojunction in the photoelectrochemical synthesis of H 2 O 2 .