In situ doping of Pt active sites via Sn in double-shelled TiO2 hollow nanospheres with enhanced photocatalytic H2 production efficiency

Abstract

A Sn⁴⁺-doped double-shelled Pt/TiO₂ hollow nanocatalyst (DHS-SnPt) with excellent photocatalytic H₂ production efficiency was prepared successfully via a facile hydrothermal method. In the catalytic system, Pt active sites were in situ reduced by Sn²⁺ and showed an enhanced interaction with Sn species. The enhanced SnO₂/Pt interface could accelerate the migration rate of e⁻ from SnO₂ to Pt, improving the charge separation efficiency of h⁺ and e⁻. The as prepared DHS-SnPt contained a very low Pt content (0.24 wt%) and showed the highest photocatalytic H₂ production efficiency (ca. 18 496 μmol g⁻¹ within 3 h), nearly 5.8 and 1.678 times as high as that of a pure double-shelled Pt/TiO₂ hollow nanocatalyst and the traditional Sn⁴⁺ doped counterpart, respectively, demonstrating the significantly improved Pt atom utilization of DHS-SnPt in photocatalytic H₂ evolution activity. On the basis of experimental results, a possible photocatalytic H₂ production mechanism was proposed to explain the excellent H₂ production efficiency of DHS-SnPt.