Patterning alternate TiO2 and Cu2O strips on a conductive substrate as film photocatalyst for Z-scheme photocatalytic water splitting

Semiconductor heterostructures mediated by electrical conductors are very promising for Z-scheme pho-tocatalytic water splitting. In contrast to conventional particulate heterostructures, alternate TiO2 and Cu2O film stripes patterned parallel on a fluorine-doped tin oxide (FTO) conductive substrate was fabri-cated as a model film photocatalyst to study the characteristics of the photogenerated charge transfer process. The Z-scheme transfer process with an effective transport distance of up to 5lm occurs only in regions distant from the TiO2/Cu2O strip edges through the FTO substrate from the bottom. In contrast, the transfer of charge around their contact regions follows the conventional transfer process through the TiO2/Cu2O strip interface. These results indicate that the Z-scheme transfer process occurring in such a large region dominates the charge transfer processes in the TiO2/FTO/Cu2O pattern film heterostructure. Importantly, unlike the single component film, which is inactive for photocatalytic overall water splitting, the modified TiO2/Cu2O pattern film can induce photocatalytic overall water splitting at a stoichiometric H2/O2 ratio close to 2:1. These findings have significant implications in designing efficient heterostruc-tures by employing a Z-scheme charge transfer process. (c) 2022 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.

Automated summary

Semiconductor heterostructures mediated by electrical conductors show great potential for Z-scheme photocatalytic water splitting. The fabricated TiO2 and Cu2O film stripes on a conductive substrate exhibit efficient charge transfer processes and enable photocatalytic overall water splitting.