Cobalt containing microporous aluminohosphates as new photocatalyst for hydrogen generation under visible irradiation

Highlights: • AlPO-5 and AlPO-11, CoAlPO4-5 and CoAlPO4-11 were synthetized by hydrothermal method. • Cobalt modified AlPO shows photo-catalytic activity under visible light irradiation. • High activity for hydrogen evolution with CoAPO4-11photo-catalyst. • High specific surface area of CoAlPO increased the (e-/h+) pairs transfer. - Abstract: Novel photocatalytic materials based on cobalt type aluminophosphate molecular sieves have been elaborated by hydrothermal method. The photocatalytic activity of CoAlPO₄-5 and CoAlPO₄-11 were evaluated for hydrogen production via water reduction under visible irradiation. The synthesized materials were characterized thoroughly with respect to elemental analysis, XRD, SEM, FTIR, DR, BET and NH₃ desorption measurement. Electrical conductivity, photo-electrochemical measurements were also studied. Since AlPO₄ materials possess a unique chemical composition as well as structural and micro-morphological characteristics. The photocatalysts have shown a remarkable surface area ∼ 183 and 258 m² g⁻¹ which lead to a better acceleration of the charge (e-/h⁺) transfer by increasing the number of surface reaction sites. Under visible light, the photocatalysts exhibited a good photo-reactivity for hydrogen production with a yield of 64 and 1260 μmol g⁻¹ min⁻¹ for CoAlPO₄-5 and CoAlPO₄-11, respectively.