CTAC-assisted monoclinic BiVO4 with oxygen defects for efficient photocatalytic performances: A combined experimental and DFT study

Developing a photocatalyst with high photocatalytic efficiency, chemical stability, and self-degradation capability is essential for optimizing photodegradation processes in environmental applications. In this study, we synthesized a monoclinic BiVO4 photocatalyst whose surface morphology was modulated by hexadecyltrimethylammonium chloride (CTAC) using a facile hydrothermal method. Experimental results demonstrated a substantial increase in the degradation rate (99%) for the CTAC-modified monoclinic BV/CT25 photocatalyst (with an initial CTAC concentration of 25g/L) compared to the CTAC-free tetragonal BiVO4 photocatalyst (73%). This highlights the effective enhancement of photocatalytic degradation performance through CTAC modification. Furthermore, density functional theory (DFT) calculations revealed that the band gap of BV/CT25 remained unchanged, suggesting that changes in oxygen vacancies (OVs) and density of states, along with the porous lattice structure, contributed to the improved performance. These findings were further supported by SEM, as well as EPR and XPS characterizations. In addition, photodegradation tests at various pH conditions and cyclic tests suggested that the modification enhanced the morphological stability and reusability of the modified BiVO4 photocatalysts. Overall, this study provides valuable insights into the design of next-generation photocatalysts, leveraging surfactants to control surface properties and emphasizing the key attributes of high photocatalytic efficiency, chemical stability, and improved reusability.