A ZnO/TiO2 composite layer was fabricated on top of a nanoporous TiO2 layer to form a heterostructure bilayer photoanode (P-PZ). The in-situ scattering sites of ZnO were formed inside the assembled photoanode (P-PZ) through the dissolution of ZnO particles caused by soaking in titanium tetrachloride solution. In comparison, the conventional TiO2 photoanodes (2P) and photoanodes with incorporation of the commercial large TiO2 particles (P-PT) were also prepared, and the three photoanodes (2P, P-PT, P-PZ) were all with the thickness of about 14.2 mu m. A light-to-electricity conversion efficienc...
