Jamdagni Pooja, Kumar Ashok, Srivastava Sunita, Pandey Ravindra, Tankeshwar K
Department of Physics and Astrophysics, Central University of Haryana, Mahendragarh, 123031, India.
Department of Physics, Central University of Punjab, Bathinda, 151401, India.
Phys Chem Chem Phys. 2022 Sep 21;24(36):22289-22297. 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-PtX (X = S, Se) and Janus β-PtSSe monolayers were investigated based on the density functional theory. The small cleavage energy for β-PtS (0.44 J m) and β-PtSe (0.40 J m) endorses the possibility of mechanical exfoliation from their respective layered bulk materials. The calculated results revealed that the β-PtX monolayers have an appropriate bandgap (∼1.8-2.6 eV) enclosing the water redox potential, light absorption coefficient (∼10 cm), 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 × 10 cm V S), 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-PtSe (∼16%) and β-PtSSe (∼18%) makes them promising candidates for solar water splitting applications.
高效的光催化水分解过程以产生清洁能源需要新型半导体材料来实现高的太阳能到氢能的转换效率。在此，基于密度泛函理论研究了各向异性的β-PtX（X = S，Se）和Janus β-PtSSe单层的光催化性能。β-PtS（0.44 J/m）和β-PtSe（0.40 J/m）的小解理能证明了从其各自的层状块状材料进行机械剥离的可能性。计算结果表明，β-PtX单层具有合适的带隙（约1.8 - 2.6 eV），涵盖水的氧化还原电位、光吸收系数（约10 cm）和激子结合能（约0.5 - 0.7 eV），这有利于实现优异的可见光驱动光催化性能。值得注意的是，固有的结构各向异性导致各向异性的高载流子迁移率（高达约5×10 cm²V⁻¹S⁻¹），从而导致光生载流子的快速传输。特别地，对于β-PtSe（约16%）和β-PtSSe（约18%），实现析氢反应和析氧反应过程所需的小外部电位以及优异的太阳能到氢能的转换效率使其成为太阳能水分解应用的有前景的候选材料。
