LAUSR

Abstract Cobalt titanate (CoTiO3) is one of the promising candidates for visible-light-driven photocatalytic water oxidation. In this research, the formation of multilayered 3D porous structures was performed by mixing Co3O4 and TiO2 nanopowders with adding pore-forming agents and further calcination. Different crystallite sizes of porous CoTiO3 were produced by varying the calcination temperature. The fabricated 3D porous CoTiO3 were characterized using XRD, SEM, BET, optical measuring technique. The crystallite size increases with increasing the calcination temperature within the range of 600–800 °C. The photocatalytic activity of 3D porous CoTiO3 was studied by measuring the rate of H2 evolution during the splitting in 0.5 M KOH aqueous solution electrolyte under 300 mW/cm2 xenon lamp irradiation. The SEM images and BET analysis show that an increase in the calcination temperature leads to a decrease of porosity CoTiO3 due to the agglomeration of particles. The change in values of potential and current of CoTiO3 depending on the dark and light conditions showed a certain extent under the light, which is mainly reflected in the drop of the initial voltage, and the hydrogen evolution reaction occurs under the −0.2 V bias voltage. The measured rate of hydrogen production of 3D porous CoTiO3 showed for UV irradiation of 0.3 mmol/g-h and for visible light 0.024 mmol/g-h, respectively. Gas chromatography analysis shows a 13% higher amount of hydrogen production for 3D porous CoTiO3 sample calcined at 800 °C, than at 600 °C. The results of current work not only report but also put forward a strategy of applied advantages the 3D CoTiO3 porous material for efficient visible-light photocatalytic reduction of hydrogen.