Corn husk derived activated carbon with enhanced electrochemical performance for high-voltage supercapacitors

Porous carbons are considered as promising electrode materials for supercapacitors due to their excellent microstructural properties. Synthesizing porous carbon from a bio-waste material has received significant importance due to their natural abundance and low-cost. Here we report the synthesis of porous carbon from a bio-waste, sweet corn husk precursor. Influence of morphology and crystallinity of pre-activated carbon on the microstructural properties of the resultant activated carbons are studied. The chemical activation method results in carbon with turbostratic nature, high specific surface area (1370 m2 g-1) with large mesoporous volume fraction and 2D layered-like morphology. Similar specific surface area is observed for samples prepared with the variation in the amount of activating agent due to higher pre-carbonization temperature. The resultant activated carbon (ASCH-1:1) shows a specific capacitance of 127 F g−1 with low energy density (4.4 Wh kg−1) in 6 M KOH electrolyte. A high energy density of 20 Wh kg−1 is obtained in 1 M TEABF4/AN electrolyte with a high specific capacitance of 80 F g−1 at 1 A g−1. It shows good cyclic stability by retaining 90% of initial capacitance after 5000 cycles at 2 A g−1. Our results demonstrate that activated carbons reported here are promising materials for high operating voltage supercapacitors

Sweetcorn husk derived porous carbon with inherent silica for ultrasensitive detection of ovarian cancer in blood plasma

Ovarian cancer is the foremost cause of death in women in the category of gynaecological malignancy. Fostering a high survival rate requires early prognosis and therefore needs ultrasensitive detection of a biomarker such as fibronectin, a glycoprotein in the extracellular matrix having a high prognostic value for ovarian cancer. Thus, such an application needs a cost-effective sensing material that possesses a high surface to volume ratio, good conductivity, and strong affinity towards biomolecules. Smartly engineered bio-wastes have shown notable potential in biosensors due to their innate biocompatibility albeit seldom utilized due to poor biomolecular interaction (sensitivity). In this work, a novel biosensor, based on sweet corn husk (bio-waste) derived porous carbon is demonstrated for a label-free ultra-detection of fibronectin protein. The reported porous carbon has high significance owing to high specific surface area (500 m2 g−1), excellent conductivity, and high affinity toward biomolecules due to the inherent presence of silica on the carbon surface. The announced biosensor presents a broad range (100 fg mL−1–10 μg mL−1) of detection with a sterling sensitivity (124.5 (KΩ/µg mL−1)/cm2) and a LOD of 129 fg mL−1. Further, it shows excellent selectivity, interference resistance response, reproducibility, high linearity and good stability, hence exhibiting a towering potential for real sample tests. © 202

In-situ formation of mesoporous SnO2@C nanocomposite electrode for supercapacitors

In this work, we report a supercapacitor based on SnO2@C composite electrode with better electrochemical performance. SnO2@C composite is synthesized from porous polymer beads by the impregnation method. The resultant composite is porous and retains uniform spherical morphology of polymer beads. The composite exhibits the bimodal distribution of pores with a specific surface area of 286 m2g−1. SnO2@C composite electrode show specific capacitance of 432 F g−1 at 1 A g−1 in 1M KOH electrolyte with capacitance retention of 95.5% for 2000 cycles. Besides, the composite electrode shows an energy density of 29.4 Wh kg−1 at a power density of 418 W kg−1 at 1 A g−1 current density. The optimize electrode design improves cyclic stability due to reducing crystal growth of SnO2 as well as diffusion kinetics because of the presence of bimodal pores which provides continuous electron path. The bimodal micropores and mesopores in carbon matrix have the accessibility of electrolyte to SnO2, improving overall electrochemical performance and therefore SnO2@C composite is suitable as electrode material for supercapacitors