Computational dissection of 2-dimensional tetrahexagonal InN alloys: Anisotropic mechanical, electronic, and charge carrier transport properties for photocatalytic water splitting

2D materials with unique physical properties lead to new possibilities in future nanomaterial-based applications. Among them, 2D structures which are suitable to be the solar-driven catalyst for water splitting reactions have become excessively important since the demand for clean energy sources increases. Apart from the conventional crystals with well-known symmetries, recent studies showed that materials that have exotic decorations could possess superior features. In this respect, we report novel 2D tetrahexagonal (th-) InN crystal and its ordered alloys that can be utilized as effective catalysts for water splitting reactions. Proposed structures possess robust stability with a versatile mechanical response. After a critical tensile strain value, all monolayers exhibit strain-induced Negative Poisson's ratio in a particular crystal direction, making them half-auxetic materials. The examined materials are indirect semiconductors with desired bandgaps and band edge positions for water splitting applications. Due to their structural anisotropy, they have direction-dependent mobility that can keep the photogenerated charge carriers separated by reducing their recombination probability, which boosts the photocatalytic process. Relatively high absorption capacity in the wide spectral range underlines their potential performance. The novel properties of 2D th-InN and its alloys, indicate that they can be used for water splitting applications in near future.