Photocatalytic H_2 production has emerged as one of the most clean and promising renewable energy sources. In spite of the efforts to obtain efficient photocatalysts able to produce H_2 from Sun light and water, there is still the need to prepare cheaper and environmental friendlier photocatalysts. Phosphatebased materials could be good candidates to fulfill these requirements. In this manuscript we have prepared a set of mixed Ti~(3+)/Ti~(4+) valence, open-framework titanium phosphates(of-TiPO_4) and mixed titanium oxide/phosphate derivatives(cr-Ti P), correlating their structure and composition with the photocatalytic activity for H_2 production. We determined that mixed titanium oxide/phosphate crystalline phases produced enhanced H_2 evolution under Sun simulated light irradiation than mixed Ti~(3+)/Ti~(4+) valence, open-framework titanium phosphates and titanium oxide phases. Photocatalytic H 2 production has emerged as one of the most clean and promising renewable energy sources. In spite of the efforts to obtain efficient photocatalysts able to produce H_2 from Sun light and water, there is still the need to prepare cheaper and environmental friendlier photocatalysts. Phosphatebased materials could be good candidates to fulfill these requirements. In this manuscript we have prepared a set of mixed Ti ~ (3 +) / Ti ~ (4+) valence, open-framework titanium phosphates (of-TiPO_4) and mixed titanium oxide / phosphate determined (cr-Ti P), correlating their structure and composition with the photocatalytic activity for H 2 production. We determined that mixed titanium oxide / phosphate crystalline parts produced enhanced H 2 evolution under Sun simulated light irradiation than mixed Ti ~ (3 +) / Ti ~ (4+) valence, open-framework titanium phosphates and titanium oxide phases.