Solid-state Synthesis of Phase Pure CuBi2O4 by Sequential Ball Milling

Bismuth-based metal oxides are an intriguing class of photoelectrode materials that can potentially enable large-scale solar hydrogen production via photoelectrochemical (PEC) water-splitting. For realizing such PEC devices, Kusachiite (copper bismuth oxide) is one of the most promising photocathode materials for high solar to hydrogen efficiency. Here we attempt to synthesize phase pure copper bismuth oxide (CuBi2O4) nanopowders using a facile solid-state reaction technique subsequently sintered at 750 0C for 4 h in air. These CuBi2O4 (CBO) powders have been further sequentially ball milled (SBM) up to 25 h to elucidate the milling duration effect on the optical bandgap of the ball milled CuBi2O4 (SBM-CBO). The structural, optical, and Raman studies suggest that phase pure tetragonal CBO could be grown from raw CuO and Bi2O3 powders. The variations in morphology and chemical composition of CBO with increasing milling hours were examined using field emission scanning electron microscopy (FE-SEM) and Energy Dispersive X-ray (EDX) microanalysis, respectively. The optical bandgap was measured in the range of 1.70 - 1.85 eV from the UV-VIS-NIR Diffuse reflection data of SBM-CBO powders. The CBO photocathode materials with variable structural and optical properties could be a promising candidate for self-sustained PEC generation of hydrogen fuel.Comment: 4 pages, 5 figures, 2022 4th International Conference on Sustainable Technologies for Industry 4.0 (STI

Anti-diarrheal activity and brine shrimp lethality bioassay of methanolic extract of Cordyline fruticosa (L.) A. Chev. leaves

Abstract Background Cordyline fruticosa (L.) A. Chev. (Asparagaceae) is a plant which is traditionally used for the treatment of cough, bloody cough, diarrhea, dysentery, high fever, difficulties in urine, bloody urine, small pox, madness, skin eruptions, joint pains, rheumatic bone pains, sore throat, neck pain, bleeding hemorrhoids and inflammation in the digestive tract. Therefore, the present work aims to investigate the antidiarrheal and cytotoxic activities of methanolic extract of Cordyline fruticosa leaves in mice and brine shrimp, respectively. Methods The effects of the methanol extract of Cordyline fruticosa leaves (MCFL) on castor oil-induced diarrhea, magnesium sulphate induced diarrhea and charcoal meal test in mice were investigated. In addition, brine shrimp lethality bioassay method was used to evaluate cytotoxic activity of MCFL. Results In castor oil induced diarrheal test, MCFL at the dose of 200, 400 and 800 mg/kg body weight significantly (∗ P< 0.05, versus control) and dose-dependently reduced the frequency of diarrhea. The frequency of magnesium sulphate-induced diarrhea was significantly reduced by MCFL at the dose of with 800 mg/kg. In the charcoal meal test, the extract at the dose of 400 and 800 mg/kg body weight significantly (∗ P< 0.05) reduced the distance travelled by charcoal along the intestinal tract when compare with control. However, in brine shrimp lethality test after 24 h, surviving brine shrimp nauplii were counted and LC50 was assessed. The extract exhibited considerable toxicity towards brine shrimp with LC50 value of 355.7 μg/mL,with respect to standard vincristine sulfate (having LC50 of 3.8 μg/mL). Conclusion The results of present investigation suggest that methanolic extract of Cordyline fruticosa leaves possesses antidiarrheal and cytotoxic activities, confirming the traditional use of the plant in the treatment of diarrhea