NiFe oxyhydroxide decorated TiO₂ nanotube photoanodes for improved photoelectrochemical oxidation performance

Developing highly efficient and durable semiconductor photoelectrodes has become a great significance for the synthesis of clean fuels and valuable chemical products via photoelectrochemical (PEC) cell. Herein, TiO₂ nanotube array–supported amorphous cocatalyst NiFe oxyhydroxides (NiFe-OOH/TiO₂ NTs) were constructed by the electrodeposition method. Surprisingly, the prepared amorphous NiFe oxyhydroxides were uniformly decorated on the surface of TiO₂ nanotubes without the agglomeration, which were conducive to the separation and transfer of photogenerated carriers. These nanoarchitectonics of NiFe-OOH/TiO₂ NTs were favorable for promoting both the water oxidation and the selective oxidation of benzyl alcohol (BA). NiFe-OOH/TiO₂ NTs demonstrated admirable stability for the water oxidation, reaching the photocurrent density of 0.49 mA cm⁻² at 1.23 V vs. RHE. Furthermore, the conversion efficiency and the selectivity of BA to benzaldehyde under neutral conditions were as high as 67.7% and 84.7%, respectively. This work may provide a simple method for preparing efficient and durable photoelectric electrodes to improve the oxidation performance of PEC cell. Graphical abstract: [Figure not available: see fulltext.]