Sustainable synthesis of AgNPs/strontium-titanate-perovskite-like catalysts for the photocatalytic production of hydrogen

SrTiO3-cubic-like photocatalysts with average size of 35-40 nm were synthesized in 2 h without further calcination treatment. Structural defects or contamination were negligible according to the DRX and FTIR analyzes. The H-2 generation rates were 386 and 463 mu mol h(-1) g(-1) using an ethanol-water scavenger suspension with the SrTiO3 and Ag/SrTiO3 oxides, respectively. In comparison with other works reported in the literature, the hydrothermal synthesis of SrTiO3 and the UV-pen lamp radiation used for the H-2 production may open a new strategy for the sustainable synthesis of 3-dimensional photoactive nanomaterials. The functionalization of nanocubes with highly monodispersed silver or rhodium nanoparticles provided an additional increase in the hydrogen photoproduction rate. In this sense, the silver nanoparticles (AgNPs) act as a sink for the photogenerated electrons through a Schottky barrier in the metal-perovskite contact region, boosting up the separation of the charge carriers. The identification of the surface species by XPS as well as the Rhodamine B photooxidation were performed to better understand the surface backward reaction in the photocatalytic production of hydrogen. The AgNPs worked as co-catalysts, preserving the stability of the most photoactive catalysts for 32 h.