HIGH-PERFORMANCE THIN-LAYER CHROMATOGRAPHY ANALYSIS AND FREE RADICAL SCAVENGING POTENTIAL OF SOUTH INDIAN ORTHODOX BLACK TEA

Objective: The objective of this study was to evaluate the free radical scavenging potential and high-performance thin-layer chromatography (HPTLC) fingerprinting of the ethanolic extract of south Indian orthodox black tea (OBT).Methods: Phytochemical analysis was carried out using standard methods, and free radical scavenging activity of the extract was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), superoxide anion (SOD), and hydroxyl radical scavenging capacities. The ethanolic extract of OBT was loaded in the pre-coated HPTLC plates (silica gel 60 F 254) E-MERCK KGaA. HPTLC was carried out with toluene: ethyl acetate: diethylamine (7:2:1), chloroform: methanol:formic acid (8.5:1.0:0.5), and butanol: isopropyl alcohol (1:1) as mobile phase for alkaloids, flavonoids, and terpenoids, respectively.Results: HPTLC results confirmed that the extract contained several potential active components such as flavonoids, alkaloids, and terpenoids as the slides revealed multicolored bands of varying intensities. Extract of OBT reliably showed the total phenolics 132.27 mg/g, flavonoids 72.52 mg/g, and alkaloids 66.01 mg/g of dry matter. The IC50 value of OBT for DPPH was found to be 372.22 μg/ml, SOD 311.93 μg/ml, NO 362.17 μg/ml, hydroxyl radical 342.14 μg/ml, and reducing power 178.54 μg/ml.Conclusion: The HPTLC fingerprinting profile developed for ethanolic extract will help in proper identification and quantification of marker compounds. The ethanolic extract of OBT was found to possess a wide range of phytochemicals with excellent antioxidant properties. This information may help to choose the best beverage to be consumed in the future

Augmenting the Photocatalytic Performance of Direct Z-Scheme Bi2O3/g-C3N4 Nanocomposite

Huge demands for photocatalytically efficient visible-light-induced catalysts have spurred widespread interest in building adaptable heterojunctions. Here, we used in situ thermal polymerization to synthesise the Z-scheme Bi2O3/g-C3N4 heterojunction. The optical, structural, chemical, compositional and photocatalytic behaviours of the samples were analysed through various analytical techniques and photocatalytic methylene blue (MB) dye degradation reaction. Among the various ratios of Bi2O3/g-C3N4 heterojunction composites, the 1:1 ratio showed improved visible-light-induced catalytic activity, which attained 91.2% degradation efficiency after 120 min of visible-light exposure. The dye degradation efficiency was calculated under various environmental conditions by varying the dye concentration, solution pH and catalyst dosage. A improved Z-scheme photocatalytic mechanism was proposed in light of the results. A potential mechanism was suggested to explain the photocatalytic activity, and trapping experiments supported it. Last but not least, this strategy might be helpful to prepare the heterojunction photocatalyst for the degradation of organic pigments

Augmenting the Photocatalytic Performance of Direct Z-Scheme Bi₂O₃/g-C₃N₄ Nanocomposite

Huge demands for photocatalytically efficient visible-light-induced catalysts have spurred widespread interest in building adaptable heterojunctions. Here, we used in situ thermal polymerization to synthesise the Z-scheme Bi2O3/g-C3N4 heterojunction. The optical, structural, chemical, compositional and photocatalytic behaviours of the samples were analysed through various analytical techniques and photocatalytic methylene blue (MB) dye degradation reaction. Among the various ratios of Bi2O3/g-C3N4 heterojunction composites, the 1:1 ratio showed improved visible-light-induced catalytic activity, which attained 91.2% degradation efficiency after 120 min of visible-light exposure. The dye degradation efficiency was calculated under various environmental conditions by varying the dye concentration, solution pH and catalyst dosage. A improved Z-scheme photocatalytic mechanism was proposed in light of the results. A potential mechanism was suggested to explain the photocatalytic activity, and trapping experiments supported it. Last but not least, this strategy might be helpful to prepare the heterojunction photocatalyst for the degradation of organic pigments