OER Activity Promoted by Organic Ligand-Free Cs2Pt(Cl, Br)6 Perovskite Photocatalyst for Solar-Driven Water Splitting

Mego K.; Ruiz-Campos P.; Baldoví H.G.; Atienzar P. · Advanced Energy and Sustainability Research (2026) · DOI: 10.1002/aesr.202500105

Resumen

The development of lead-free perovskites as environmentally sustainable materials has gained significant attention for their applications in solar cells and photocatalysis. In this study, Cs2PtCl6 and Cs2PtBr6 vacancy-ordered double perovskites are synthesized via a hydrothermal method and evaluated as ligand-free photocatalysts for solar-driven water splitting, targeting the oxygen evolution reaction (OER). Structural characterization confirms their cubic phase, and ultraviolet-visible diffuse reflectance spectroscopy reveals optical bandgaps of 2.17 eV for Cs2PtCl6 and 1.94 eV for Cs2PtBr6. Theoretical calculations based on density of states analysis confirms their semiconductor behavior. Photocatalytic studies show that Cs2PtBr6 exhibits superior O2 evolution rates (368.9 μmol g−1 h−1) compared to Cs2PtCl6 (237.4 μmol g−1 h−1), attributed to its favorable electronic structure. Also, photoluminescence (PL) studies reveals that Cs2PtBr6 exhibits lower PL intensity and a longer emission lifetime (2.5 μs) compared to Cs2PtCl6 (1.3 μs). Long-term stability tests highlight moderate photostability, with Pt4+ reduction due to precipitation of Pt0 under prolonged irradiation or reuses. This research highlights the potential of Cs2PtX6 perovskites for efficient, sustainable OER catalysis while identifying challenges related to structural stability and charge recombination.

Instituciones: Universidad Científica del Sur