Effect of nitric acid on hydrothermal synthesis of Bi2WO6 nanosheets for supercapacitor application

This study delves into the synthesis of Bi2WO6 nanosheets using nitric acid (HNO3) through a hydrothermal process, focusing on the impact of HNO3 concentration on the structural, morphological, and electrochemical properties of the nanosheets. The research highlights the significant role of HNO3 in regulating nucleation, precursor chemical reactions, and crystal development, leading to the formation of ultrathin nanosheets. The study employs various characterization techniques, including XRD, FTIR, FESEM, TEM, and electrochemical analyses, to investigate the effects of HNO3 on the Bi2WO6 nanosheets. Notably, the introduction of HNO3 results in thinner, well-defined nanosheets with improved ion diffusion and charge-transfer mechanisms. The electrochemical performance of the Bi2WO6 nanosheets is evaluated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The results demonstrate that the Bi2WO6 nanosheets synthesized with HNO3 exhibit enhanced specific capacitance, excellent coulombic efficiency, and superior stability, making them promising candidates for supercapacitor applications. The study concludes that the improved electrochemical performance is attributed to the synergistic interaction between Bi2WO6 and the structural features of the nanosheets, highlighting the potential of these materials in energy storage devices.