Photoelectrochemical water oxidation through a hybrid architecture nanoparticles/nanotubes

•Three different deposition methods (hexanes, oleylamine, hydrazine) to deposit Co-P nanoparticle intermetallic compounds on the top of the TiO2 nanotube surface.•The photocurrent saturated current density is improved by 1.15-fold using the oleylamine deposition method, compared with the deposition method with hexanes.•The overall photo-saturated photocurrent density is improved up to 1.7-fold of the TiO2 NTs deposited with Co-P nanoparticles by Ar-ion sputtering.