Hierarchical Bi2S3 nanothorn on ZnO core-branch photoelectrode: A promising heterostructure for enhanced photoelectrochemical water splitting

The zinc oxide semiconductor associated with defects and their recombination effect restricts the development of photoelectrode for hydrogen evolution. The combination of semiconductor hetero-junction and hierarchical interface of ZnO/Bi2S3 photoelectrode fabricated. In this study, heterostructure ZnO/Bi2S3 were studied as a photoanode with their impact of oxygen vacancy in ZnO nano rods. The trace of the Bi2S3 on the ZnO was studied and compared with pristine and oxygen annealed ZnO nano rods. The photon-luminescence studies reveal that shallow donor and acceptor defect in ZnO and restricted by Bi2S3 heterostructure. The less defect contemplations in the photoanodes accelerates up electron and hole migration leading to significant built-in potential and photocurrent generation. The appropriate method has been followed to architype less interfacial defect in ZnO (300)/Bi2S3 photoanode and boosted the photo-redox reactions for efficient hydrogen evolution. The photoanode exhibits substantial properties of photocurrent density 0.33 mA/cm2, charge transfer resistance of 700 Omega cm2 and higher inbuilt potential of-0.88V vs Ag/AgCl with 0.17 % applied bias photon to electron conversion efficiency and 0.11 % solar to hydrogen conversion efficiency.