NbOI₂ (Niobium Oxyiodide)

NbOI₂ (Niobium Oxyiodide) — Introduction

NbOI₂ is a transition-metal oxyhalide composed of niobium (Nb), oxygen (O), and iodine (I). It belongs to the family of layered oxyhalides, with weak van der Waals interactions between layers, making it a candidate for two-dimensional (2D) materials research.

Physical Properties

Appearance: Dark crystalline solid.

Crystal Structure: Orthorhombic layered structure, where Nb is coordinated by both oxygen and iodine. Layers are stacked via weak van der Waals forces.

Electronic Properties: A semiconductor with a band gap typically in the range of 1.5–2.0 eV (depending on thickness and calculation method).

Exfoliation: The layered structure suggests it can be exfoliated into thin flakes, though oxygen–halide bonding makes it somewhat less easily cleavable than pure halides (e.g., CrI₃).

 Applications

2D Semiconductors: Candidate for optoelectronic devices such as field-effect transistors and photodetectors.

Catalysis: Potential photocatalyst due to suitable band gap and strong light absorption.

Sensors: Anisotropic optical response may be exploited in polarization-sensitive detection.