Electrochemical properties of tin oxide quantum dot decorated gC₃N₄ nanotubes: experimental and theoretical insights

We present a pioneering approach that employs tin oxide quantum dots (SnQds) integrated with graphitic carbon nitride nanotubes (gCN) to form a novel electrode material gCN-SnQd. Comparative assessments revealed that gCN-SnQd electrodes exhibited notably superior electrochemical attributes within a three-electrode configuration, surpassing their pristine gCN and SnQd counterparts. Significantly, the gCN-SnQd electrode exhibits an unwavering specific capacitance of 640.19 F·g⁻¹ with incredible discharge time of 230.4 s. The material demonstrated remarkable capacity retention, surpassing 100 %, even at a significant current density of 10 A·g⁻¹, maintaining stability after 5000 charge/discharge cycles. Furthermore, the utilization of gCN-SnQd electrodes in a symmetric supercapacitor device showcases promising energy density of 27.72 Wh·kg⁻¹ and power density of 1050 W·kg⁻¹. Employing density functional theory (DFT) calculations, we meticulously explained the enhancement in the electronic properties of gCN nanotubes upon the integration of SnQd. The empirical insights of this study offer an in-depth understanding of the potential exhibited by gCN-SnQd in augmenting the energy and power densities of supercapacitors, thereby advancing the realm of environmentally conscious energy storage technologies. This study emphasizes the pivotal role of precisely engineered nanomaterials and state-of-the-art computational methodologies in shaping the design landscape of electrode materials that exhibit exceptional and distinctive performance profiles. © 2025 The Korean Society of Industrial and Engineering Chemistry