A Facile Synthesis of FeCo Nanoparticles Encapsulated in Hierarchical N-Doped Carbon Nanotube/Nanofiber Hybrids for Overall Water Splitting

Development of efficient and cost-effective transition metal-based catalysts for overall water splitting is desired. Herein, a facile synthesis procedure for the development of FeCo bimetallic alloy nanoparticles (NPs) located on the tips of multi-walled carbon nanotubes (CNTs) supported over N-doped carbon nanofibers (CNFs) is presented. The CNTs, not only prevent FeCo NPs from agglomeration by encapsulating them at the tip but also provide an efficient electron pathway. The materials exhibited excellent performance in oxygen evolution reaction (OER) and decent activity in hydrogen evolution reaction (HER) with long-term durability of up to 48 hours on glassy carbon electrode. The best OER activity with a overpotential of 283 mV@10 mAcm(-2) and Tafel slope of 38 mV/dec was achieved with a hierarchically porous catalyst having Fe : Co molar ratio of 1 : 2. This synthesis approach is promising for growing well-dispersed CNTs over N-doped carbonaceous support using bimetallic alloys for electrocatalytic applications

ZnSe-rGO nanocomposites as photocatalysts for purification of textile dye contaminated water: A green approach to use wastewater for maize cultivation

Disputes about the probable availability of safe water and the efficacy of processed wastewater are key issues that necessitate a suitable solution to enhance the quality of clean water. The current research emphasizes the synthesis of ZnSe-reduced graphene oxide nanocomposites (ZnSe:rGO) with different weight ratios of rGO (represented as X = 0.6, 1 and 1.6 g)via one-step hydrothermal method. The photocatalytic performance for the degradation of methyl violet (MV) dye was investigated under visible light irradiation by varying the reaction parameters. The crystal structure, elemental composition, surface functionality and morphology of the synthesized ZnSe-XrGO nanocomposites were estimated by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopic (SEM) techniques. UV–visible spectroscopy was used to investigate the optical properties. The highest efficiency is obtained for ZnSe-XrGO in 1:1 and it showed pseudo 1st order behavior with rate constant of 0.0167min−1and 94 % photodegradation of MV in just 3 h. Furthermore, hazardous effects of MV were investigated on the germination and growth of Zea mays seeds by giving them aqueous solution of MV (0, 8, 12, 24 and 48 ppm) and the decontaminated water after photodegradation of MV with the synthesized photoactive composite. The results showed profound negative effect on both germination and seedling growth at higher concentration (>12 ppm) of the dye solution. No hazardous effects were observed on both these parameters when it was given the dye degraded water which reflects the practical use of the synthesized catalyst for water remediation. The current study fulfills the goal of designing an efficient visible-light active nano-photocatalyst and its direct applicability on life sciences for water purification

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population