Silver monoliths and their applications in catalytic reduction of 4-NP to 4-AP and sensing against As3+.

Autor: Nema, Ankita, Bano, Mustri, Rai, Mansi, Shrivastava, Kavya, Dangi, Sambhavna Singh, Khan, Farid
Zdroj: Journal of Porous Materials; Apr2022, Vol. 29 Issue 2, p459-471, 13p
Abstrakt: Silver monoliths using non-ionic surfactant Triton X-102 as reducing agent with and without additives such as Dextran and Ludox (SiNPs) were synthesized by modified Sol–Gel method without the use of acid or base as a catalyst. The as-synthesized monoliths were characterized by thermogravimetric analysis (TGA), X-ray diffraction (PX-RD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) surface area analysis, Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). All as synthesized monoliths worked efficiently to reduce the 4-Nitrophenol (4-NP) to 4-Aminophenol (4-AP) however; the catalyst Ag/Triton X-102/SiNPs showed catalytic activity to reduce the 4-NP to 4-AP just in 5 s, which is the minimum time to reduce 4-NP to 4-AP. The Catalyst Ag/Triton X-102/Dex/SiNPs reduced the 4-NP to 4-AP very quickly in presence of sunlight. Kinetic study confirmed the pseudo first order reaction for catalyst Ag/Triton X-102/Dex/SiNPs while remaining catalysts showed zero order kinetics. The rate constant (k), thermodynamic parameters such as activation enthalpy (ΔH‡), activation Gibbs free energy (ΔG‡), entropy of activation (ΔS‡) and energy of activation (Ea) have also been determined. Sensor Ag/Triton X-102/Dex/SiNPs/GPE detects toxic As3+ with limit of detection (LOD) and limit of quantization (LOQ) 0.561–3.26 ng mL−1 and 3.45 ng mL−1 LOQ respectively which are also the lowest limit reported. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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