Low-cost green recyclable biomaterial for energy-dependent electrical switching and intact biofilm with antibacterial properties

A Sandwich Structure Ag/MgFe2O4-Deposited Surface Carbonized Wood for Integrated Solar Steam Generation and Photoreduction of Cr(VI)

The severe deterioration of the marine ecosystem significantly negatively impacts the performance of solar-driven steam generation (SSG) and the quality of the obtained freshwater. Herein, a bifunctional Ag/MgFe2O4@SCW reactor with a sandwich structure is designed for efficient SSG and Cr(VI) reduction, which is constructed via in situ deposit Ag nanoparticles (NPs) and MgFe2O4 onto surface carbonized wood (SCW). Owing to the advanced sandwich structure and strong interfacial interactions between each component, an ultra-high evaporation rate of 1.55 kg m-2 h-1 and the efficiency of 88.6% are achieved using Ag/MgFe2O4@SCW under 1 sun. The system exhibits the long-term evaporation performance in the simulated sewage and strong acid/base solutions along with water-harvesting capacity in outdoor solar desalination. The quality of distilled water after desalination of actual seawater and NaCl solutions with different concentrations meets the WHO-recommended drinkable water standards. Furthermore, Ag/MgFe2O4@SCW shows outstanding antibacterial property, self-desalting capacity, as well as reusability and structure stability. Most importantly, the fast carrier separation endows Ag/MgFe2O4@SCW with superior photocatalytic activity and Cr(VI) photoreduction of up to 96.1% after 180 min of illumination. The bifunctional Ag/MgFe2O4@SCW reactor provides an advanced synergistic mechanism for improving SSG and photocatalytic performance, while being promising for solar-powered production of clean water.

Characterization and Evaluation of Multiple Biological Activities of Silver Nanoparticles Fabricated from Dragon Tongue Bean Outer Peel Extract

BACKGROUND

The dragon tongue beans are a legume belonging to the Fabaceae family, are rich in protein, starch, fiber, and other micronutrients that have numerous health-promoting benefits. Its peel commonly the waste parts also contains lots of bioactive compounds.

MATERIALS AND METHODS

In the current research, dragon tongue bean peels (DtbP) extract is tested for the existence of phytochemicals. Ag nanoparticles are biosynthesized using DtbP extract. The generated DtbP silver nanoparticle characterization was accomplished using UV-Vis spectral analysis, FTIR spectral analysis, SEM analysis, EDX analysis, XRD analysis, zeta potential, and DLS study. Furthermore, comparative assessment on multi-biological activities of the biosynthesized Ag nanoparticles was accomplished by employing cytotoxicity (inhibition against HepG2 cancer cells), antidiabetic (α-glucosidase inhibition assay), and antioxidant (free-radical scavenging) analysis.

RESULTS

The characterization result of the DtbP-AgNPs demonstrated that the AgNPs synthesized within 24 h. The AgNPs are nearly spherical. The biological effect assay of AgNPs displayed that DtbP-AgNPs is having significant cytotoxicity, antidiabetic, and moderate antioxidant effect. This study results as a whole report the biosynthesis of DtbP-AgNPs utilizing the legume dragon tongue bean waste peel and assessment of their multiple biological activities. The synthesized DtbP-AgNPs could serve as a potential candidate in the pharmaceutical industries in the formulation of drugs for the treatment of several medical ailments concerning cancer, diabetes, etc.

Super Hydrophilic Activated Carbon Decorated Nanopolymer Foam for Scalable, Energy Efficient Photothermal Steam Generation, as an Effective Desalination System

Clean water scarcity is still an intense, prolonged global issue that needs to be resolved urgently. The solar steam generation has shown great potential with a high energy conversion efficiency for clean water production from seawater and wastewater. However, the high evaporation rate of water cannot be preserved due to the inevitable fouling of solar absorbers. Herein, a self-floatable and super hydrophilic solar-driven steam generator composed of activated carbon coated melamine foam (ACM). The deposited ACM photothermal layer exhibits outstanding solar absorption (92%) and an efficient evaporation rate of 1.27 kg m-2 h-1, along with excellent photothermal conversion efficiency (80%) as compared to commercially available primitive solar stills. The open porous assembly of melamine foam equipped with 80% flexibility (0.8 MPa) enabled smooth water transport and sustain heat accumulation within the matrix. The thermal insulation of ACM is 10 times greater than pure water. Moreover, open porous assembly of designed solar-powered steam generator rejects salt ions as well as volatile organic compounds efficiently. The low-cost and facile fabrication of photothermal based water production presents a potential solution to single step drinking water supply from various resources of the sea, the lakes and mixtures of emulsified oil and industrial wastewater.