Photocatalytic properties of anisotropic β-PtX2 (X = S, Se) and Janus β-PtSSe monolayers

• Published in: Physical chemistry chemical physics : PCCP 2022-09, Vol.24 (36), p.22289-22297
• Main Authors: Jamdagni, Pooja, Kumar, Ashok, Srivastava, Sunita, Pandey, Ravindra, Tankeshwar, K
• Format: Article
• Language: English
• Subjects: Absorptivity; Anisotropy; Carrier mobility; Clean energy; Density functional theory; Electromagnetic absorption; Energy conversion efficiency; Excitons; Hydrogen evolution reactions; Hydrogen-based energy; Monolayers; Oxygen evolution reactions; Photocatalysis; Photovoltaic cells; Semiconductor materials; Water splitting
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d2cp02549c

The highly efficient photocatalytic water splitting process to produce clean energy requires novel semiconductor materials to achieve a high solar-to-hydrogen energy conversion efficiency. Herein, the photocatalytic properties of anisotropic β-PtX2 (X = S, Se) and Janus β-PtSSe monolayers were investigated based on the density functional theory. The small cleavage energy for β-PtS2 (0.44 J m−2) and β-PtSe2 (0.40 J m−2) endorses the possibility of mechanical exfoliation from their respective layered bulk materials. The calculated results revealed that the β-PtX2 monolayers have an appropriate bandgap (∼1.8–2.6 eV) enclosing the water redox potential, light absorption coefficient (∼104 cm−1), and exciton binding energy (∼0.5–0.7 eV), which facilitates excellent visible-light-driven photocatalytic performance. Remarkably, the inherent structural anisotropy leads to an anisotropic high carrier mobility (up to ∼5 × 103 cm2 V−1 S−1), leading to a fast transport of photogenerated carriers. Notably, the required small external potential to realize hydrogen evolution reaction and oxygen evolution reaction processes with an excellent solar-to-hydrogen energy conversion efficiency for β-PtSe2 (∼16%) and β-PtSSe (∼18%) makes them promising candidates for solar water splitting applications.