Effectively controlling Ni photodeposition on polyhedron SrTiO3via double-doped Al and Co

Abstract

SrTiO₃ micron-nano-sized particles (MNPs) have been widely applied in the photocatalysis field. Currently, many studies focus on the morphological control and heterojunction construction of SrTiO₃; however, unsuitable active sites limit their performance improvements. In this study, we developed polyhedron SrTiO₃ MNPs double doped with Al and Co, which showed outstanding in situ photo-reduction performance of Ni²⁺ (from Ni²⁺ to Ni⁰), achieving about 39% improvement in 10 minutes compared with the traditional sample doped only with Al, benefiting from the unique strengthening function of the crystal facet effect. The photo-reduction reaction of Ni²⁺ exhibited a significant selectivity on the (112) crystal facet mainly due to the changes in the surface structure, including the atomic nanoclusters (ACs) and the satellite single atom (SAs) of Co. The femtosecond transient absorption spectrum (fs-TA) revealed the difference in the excited states of photo-induced electrons for the same delay time, which was the essence of the synergistic effect between ACs and SAs. Benefitting from the above characteristics, the double-doped SrTiO₃ has high efficiency in the selective photodeposition of Ni. In addition, we established an experimental platform to assess the photo-quantum absorption efficiency of an aqueous dispersion system to verify that Ni may be an effective active site in the photocatalytic process for SrTiO₃. Therefore, this work demonstrates that these special SrTiO₃ MNPs have a huge potential application in the field of Ni recycling in wastewater or cocatalyst construction.