One-Step Solvothermal Formation of Pt Nanoparticles Decorated Pt²⁺-Doped α-Fe₂O₃ Nanoplates with Enhanced Photocatalytic O₂ Evolution

Abstract

The photooxidation of water into O2 has been identified as the barrier of water-splitting, and light-driven water oxidation catalysts have been intensively explored to develop highly active water splitting materials. Despite the fascinating advantages for photocatalytic water oxidation, such as abundance in nature, inexpensiveness, low toxicity, thermo/photostability, and suitable electronic band structures, hematite α-Fe2O3 is a poor photocatalyst for water oxidation due to its short exciton lifetime and hole diffusion length, weak carrier mobility, and shallow sunlight penetration depth. In this work, we have synthesized Pt nanoparticles decorated Pt2+-doped α-Fe2O3 nanoplates (Pt/Pt-Fe2O3 NPs) by a one-step solvothermal route which exhibit the enhanced photoactivity and photostability for water oxidation. The introduction of the Pt into the α-Fe2O3 by the means of elemental doping and nanoparticle decoration accounts for the enhanced performance. The doping of Pt2+ into α-Fe2O3 improves the isolation efficiency of the photoinduced carriers which remarkably increases the lifespan of hole carriers, and the adherence of metal Pt nanoparticles to the surface of α-Fe2O3 leads to formation of Schottky barriers at the interface which effectively impedes the combination of photogenerated electrons and holes.