Turning trash to treasure: Innovative use of exhausted desiccant waste supported zinc indium sulphide for sustainable photocatalytic abatement of tetracycline.

Employing an affordable and sustainable visible-light-driven system is crucial for organic pollutant abatement, in the field of photocatalysis. In the present investigation, a pioneering photocatalyst zinc indium sulphide, ZnIn2S4 (ZIS) supported on a silica gel matrix, SiO2 (SG) which is the leftover material after multiple rounds of dehumidification processes, was synthesized. The fabrication of the heterojunction facilitated enhancement in light absorption and charge separation efficiency. The photocatalytic performance was evaluated through the degradation of tetracycline (TC) under light irradiation. The nano-photocatalyst experienced detailed analysis using spectroscopic and microscopic methods. The ZIS/SG catalyst exhibited remarkable efficiency in degrading TC under visible light conditions, achieving a nearly 98-99% degradation. This performance surpassed the degradation rates of the original ZIS and SG catalysts by 3.6 and 4.45 times, respectively. Additionally, the catalyst was effectively used to control TC levels in real-time within pharmaceutical plant effluent, resulting in a degradation efficiency of 78.2%. With affordability, enhanced TC mineralization, and recyclability for up to six runs (efficiency ∼ 85%), the ZIS/SG photocatalyst exhibits desirable qualities of an ideal one. This innovative nano-photocatalyst introduces new possibilities for improving the process of photocatalytic decontamination of tenacious emerging pollutants by providing satisfactory reusability and stability.

Synthesis of new series of quinoline derivatives with insecticidal effects on larval vectors of malaria and dengue diseases.

Mosquito borne diseases are on the rise because of their fast spread worldwide and the lack of effective treatments. Here we are focusing on the development of a novel anti-malarial and virucidal agent with biocidal effects also on its vectors. We have synthesized a new quinoline (4,7-dichloroquinoline) derivative which showed significant larvicidal and pupicidal properties against a malarial and a dengue vector and a lethal toxicity ranging from 4.408 µM/mL (first instar larvae) to 7.958 µM/mL (pupal populations) for Anopheles stephensi and 5.016 µM/mL (larva 1) to 10.669 µM/mL (pupae) for Aedes aegypti. In-vitro antiplasmodial efficacy of 4,7-dichloroquinoline revealed a significant growth inhibition of both sensitive strains of Plasmodium falciparum with IC50 values of 6.7 nM (CQ-s) and 8.5 nM (CQ-r). Chloroquine IC50 values, as control, were 23 nM (CQ-s), and 27.5 nM (CQ-r). In vivo antiplasmodial studies with P. falciparum infected mice showed an effect of 4,7-dichloroquinoline compared to chloroquine. The quinoline compound showed significant activity against the viral pathogen serotype 2 (DENV-2). In vitro conditions and the purified quinoline exhibited insignificant toxicity on the host system up to 100 µM/mL. Overall, 4,7-dichloroquinoline could provide a good anti-vectorial and anti-malarial agent.

Bioengineered silver nanoparticles as potent anti-corrosive inhibitor for mild steel in cooling towers.

Silver nanoparticle-aided enhancement in the anti-corrosion potential and stability of plant extract as ecologically benign alternative for microbially induced corrosion treatment is demonstrated. Bioengineered silver nanoparticles (AgNPs) surface functionalized with plant extract material (proteinacious) was generated in vitro in a test tube by treating ionic AgNO3 with the leaf extract of Azadirachta indica that acted as dual reducing as well as stabilizing agent. Purity and crystallinity of the AgNPs, along with physical and surface characterizations, were evaluated by performing transmission electron microscopy, Fourier transform infrared spectroscopy, energy dispersive x-ray spectra, single-area electron diffractions, zeta potential, and dynamic light scattering measurements. Anti-corrosion studies against mild steel (MS1010) by corrosion-inducive bacterium, Bacillus thuringiensis EN2 isolated from cooling towers, were evaluated by performing electrochemical impedance spectroscopy (EIS), weight loss analysis, and surface analysis by infrared spectroscopy. Our studies revealed that AgNPs profoundly inhibited the biofilm on MS1010 surface and reduced the corrosion rates with the CR of 0.5 mm/y and an inhibition efficiency of 77% when compared to plant extract alone with a CR of 2.2 mm/y and an inhibition efficiency of 52%. Further surface analysis by infrared spectra revealed that AgNPs formed a protective layer of self-assembled film on the surface of MS1010. Additionally, EIS and surface analysis revealed that the AgNPs have inhibited the bacterial biofilm and reduced the pit on MS1010. This is the first report disclosing the application of bioengineered AgNP formulations as potent anti-corrosive inhibitor upon forming a protective layer over mild steel in cooling water towers. Graphical Abstract ᅟ.