Rhombohedral Bi ₂ Se ₃ Nanoflakes: Structural, Optical and Morphological Insights Toward Sustainable Hydrogen Energy Application

Nanostructured bismuth selenide (Bi 2 Se 3 ) was successfully synthesized using a hydrothermal method for potential application in hydrogen production. After synthesis, the obtained product was dried at 80°C and characterized using various analytical techniques. The crystalline phase and structural properties were examined by x‐ray diffraction (XRD), which confirmed the formation of rhombohedral Bi 2 Se 3 with diffraction patterns in good agreement with standard JCPDS data. Surface morphology analyzed through Field Emission–Scanning Electron Microscopy (FE‐SEM) revealed a dense, uniform nano‐flower like morphology suitable for catalytic application. Elemental composition, chemical state and electronic state was studied using x‐ray photoelectron spectroscopy (XPS) indicated nearly stoichiometric ratios of bismuth and selenium, confirming the 3 + and 2 − oxidation states by bismuth and selenium respectively. Functional groups and bonding characteristics were further identified using Fourier Transform Infrared Spectroscopy (FTIR), supporting the formation of Bi–Se bonds. The structural integrity, uniform morphology and near‐stoichiometric composition of the synthesized Bi 2 Se 3 suggest that the material possesses promising physicochemical properties required for efficient hydrogen generation. After 240 min of illumination, Bi 2 Se 3 achieves 7200 µmol h − 1 g − 1 hydrogen evolution indicating high photocatalytic activity. These results demonstrate that hydrothermally synthesized bismuth selenide can serve as a potential catalyst for hydrogen production applications.