Enhanced Photoelectrochemical Water Splitting Using Bismuth/Bismuth Selenide Nanocomposites
Sumayyah Khan, Manzar Sohail, Geoffrey Will, Anthony O' Mullane, Ahmed Abdala, Md A. Wahab
Abstract
Abstract Solar‐driven photoelectrochemical water splitting is a promising method for generating renewable and sustainable energy, as it effectively harnesses sunlight to convert it into chemical bonds. Among the many materials explored for photoelectrochemical water oxidation, metal selenides stand out because of their narrow band gaps. In this study, we successfully developed a high‐performance heterojunction nanostructure comprising a p‐type Bi/Bi 2 Se 3 photocathode using a facile solvothermal method for efficient water splitting. Various characterization techniques confirmed the structural and optical properties of the fabricated Bi/Bi 2 Se 3 nanocomposite. X‐ray diffraction (XRD) patterns along with Transmission Electron Microscopy (TEM) images, indicated a single‐phase rhombohedral Bi 2 Se 3 crystal structure, along with Bi nanoparticles, confirmed the formation of a Bi/Bi 2 Se 3 nanocomposite, while X‐ray photoelectron spectroscopy (XPS) and energy dispersive X‐ray (EDX) demonstrated the successful formation of heterojunctions. The as‐prepared photocatalyst exhibited an impressive photocurrent density of 395 μAcm −2 at 0 V versus RHE, which is approximately eight times superior to Bi 2 Se 3 . Detailed electrochemical characterization revealed that the high photocurrent density of Bi/Bi 2 Se 3 is due to improved light harvesting capability, enhanced charge separation, and a suppressed water oxidation back reaction. This innovative approach represents a significant advancement in solar‐driven photoelectrochemical water splitting for sustainable energy production.