Universal Deposition Strategy of Nanoporous Complex Oxide Thin Films for Photoelectrochemical Applications

Developing facile approaches to prepare well-designed semiconductor nanostructures is an important goal for solar water splitting. Herein, a general solution method is reported that employs citrate to complex diverse metal cations and affords uniform nanoporous multiple oxide thin films with controllable porosity by spray pyrolysis. By using CuBi 2 O 4 as a model material, a remarkable improvement in internal quantum efficiency and the impacts of the morphology on photoelectrochemical (PEC) performance is demonstrated. The morphology can be controlled by kinetically coordinating the relative rates between the gelation and the auto-combustion of citrate in the spraying process. Furthermore, the synthesis technique can be applied in a general fashion to the preparation of a wide variety of well-crystallized nanoporous oxide thin films with tunable morphologies for PEC and other heterogeneous catalysis applications.