Fabrication of a Biomass-Derived Activated Carbon-Based Anode for High-Performance Li-Ion Batteries.

Porous carbons are highly attractive and demanding materials which could be prepared using biomass waste; thus, they are promising for enhanced electrochemical capacitive performance in capacitors and cycling efficiency in Li-ion batteries. Herein, biomass (rice husk)-derived activated carbon was synthesized via a facile chemical route and used as anode materials for Li-ion batteries. Various characterization techniques were used to study the structural and morphological properties of the prepared activated carbon. The prepared activated carbon possessed a carbon structure with a certain degree of amorphousness. The morphology of the activated carbon was of spherical shape with a particle size of ~40-90 nm. Raman studies revealed the characteristic peaks of carbon present in the prepared activated carbon. The electrochemical studies evaluated for the fabricated coin cell with the activated carbon anode showed that the cell delivered a discharge capacity of ~321 mAhg-1 at a current density of 100 mAg-1 for the first cycle, and maintained a capacity of ~253 mAhg-1 for 400 cycles. The capacity retention was found to be higher (~81%) with 92.3% coulombic efficiency even after 400 cycles, which showed excellent cyclic reversibility and stability compared to commercial activated carbon. These results allow the waste biomass-derived anode to overcome the problem of cyclic stability and capacity performance. This study provides an insight for the fabrication of anodes from the rice husk which can be redirected into creating valuable renewable energy storage devices in the future, and the product could be a socially and ethically acceptable product.

Role of polyphenols in combating Type 2 Diabetes and insulin resistance.

Compromised carbohydrate metabolism leading to hyperglycemia is the primary metabolic disorder of non-insulin-dependent diabetes mellitus. Reformed digestion and altered absorption of carbohydrates, exhaustion of glycogen stock, enhanced gluconeogenesis and overproduced hepatic glucose, dysfunction of ß-cell, resistance to insulin in peripheral tissue, and impaired insulin signaling pathways are essential reasons for hyperglycemia. Although oral anti-diabetic drugs like α-glucosidase inhibitors, sulfonylureas and insulin therapies are commonly used to manage Type 2 Diabetes (T2D) and hyperglycemia, natural compounds in diet also play a significant role in combating the effect of diabetes. Due to their vast bioavailability and anti-hyperglycemic effect with least or no side effects, polyphenolic compounds have gained wide popularity. Polyphenols such as flavonoids and tannins play a significant role in carbohydrate metabolism by inhibiting key enzymes responsible for the digestion of carbohydrates to glucose, viz. α-glucosidase and α-amylase. Several polyphenols such as resveratrol, epigallocatechin-3-gallate (EGCG) and quercetin enhanced glucose uptake in the muscles and adipocytes by translocating GLUT4 to plasma membrane mainly by the activation of the AMP-activated protein kinase (AMPK) pathway. This review provides an insight into the protective role of polyphenols in T2D, highlighting the aspects of insulin resistance.

Monitoring Food Spoilage Based on a Defect-Induced Multiwall Carbon Nanotube Sensor at Room Temperature: Preventing Food Waste.

We have developed an electronic nose based on carbon nanotubes (CNTs) synthesized by using a plasma-enhanced chemical vapor deposition, aiming to be a convenient monitoring device for food spoilage. The prepared CNTs showed a crystalline structure and smooth surface with a diameter of 11.3 nm and a length of ∼10 µm. The Raman spectrum showed that the CNTs fabricated were multiwalled carbon nanotubes (MWCNTs). The characteristic graphite peak (G) observed at 1595 cm-1 in the Raman spectrum showed low intensity as compared to the defect peak (D) observed at 1330 cm-1, which referred to defect-induced points in CNTs. The CNTs were used to fabricate a sensor for ethylene gas produced by banana fruits for in situ measurements at room temperature. The sensor demonstrated good performance toward detecting the produced gas. The gas sensing signal was used as early indicators of the spoilage to help prevent food waste. The calibration curve was shown for the sensor responses evaluated at ripening days over 5 days. The sensor showed a response of 3.2% on the first day and increased to ∼7.0% by the third day and then gradually decreased. This sensor is appropriate for detecting the spoilage of food because it shows a good sensing response to a low level of produced gas from a single banana. Insight into food spoilage status of a specific level of gas shows its potential to be applied for quality assurance of food. The sensor sensitivity toward ethylene produced by a banana was confirmed based on the sensor response toward chemical ethylene gas.