Thermocatalytic Activity of Gold Truncated Nanopyramids on Strontium Titanate Nanocube

Gold truncated nanopyramids smaller than 10 nm with clean surfaces were formed on SrTiO3 naocubes (Au TNPy//SrTiO3 NCs, // denotes heteroepitaxial junction) by the deposition precipitation method without surface modifier, while the shape of Au nanoparticles (NPs) on irregular shaped SrTiO3 NPs was hemisphere-like (Au HS/SrTiO3 NPs). As a probe reaction, the oxidation of o-phenylenediamine (OPD) to 2,3-diaminophenazine (DAP) by H2O2 was carried out with the catalysts in the dark at 25 °C. Au TNPy//SrTiO3 NCs exhibit significantly higher catalytic activity for the oxidation reaction than Au HS/SrTiO3 NPs. Kinetic analyses indicated that H2O2 can be more effectively activated to be utilized for the OPD oxidation in the former system than the latter system. Heteroepitaxial junction with SrTiO3 nanocubes induces faceting of Au nanoparticles to produce truncated nanopyramids <10 nm with clean surfaces (Au TNPy//SrTiO3 NCs, // denotes heteroepitaxial junction). Au TNPy//SrTiO3 NCs exhibit significantly higher catalytic activity than usual hemisphere-like Au nanoparticle-loaded irregular shaped SrTiO3 nanoparticles (Au HS/SrTiO3 NPs) for the oxidation of o-phenylenediamine to 2,3-diaminophenazine by H2O2.