Self-template impregnated silver nanoparticles in coordination polymer gel: photocatalytic CO2 reduction, CO2 fixation, and antibacterial activity

Abstract

CO₂ fixation and light-assisted conversion of CO₂ in the presence of water into fuels and feedstocks are clean and sustainable techniques to alleviate the energy crisis and global climate change. In this regard, herein, a waterborne multifunctional metal–organic coordination polymer gel (Ag@GMP) was prepared from silver nitrate and guanosine 5′-monophosphate. Electron microscopy exhibits that Ag@GMP has a flower-like structure, which is composed of vertically grown sheets, and corresponding high magnification images display the presence of silver nanoparticles on the vertically grown sheets. Ag@GMP demonstrates remarkable photocatalytic performance, achieving a CO₂ conversion rate of 18.6 μmol g⁻¹ with approximately 85% selectivity towards CO at ambient temperature without using sacrificial agents. In situ diffuse reflectance infrared Fourier transform spectroscopy was employed to elucidate the proposed mechanism for photocatalytic CO₂ reduction. Additionally, Ag@GMP exhibits significant catalytic activity in the fixation of CO₂ with epoxides, leading to the formation of valuable chemicals under atmospheric pressure. Ag@GMP demonstrated efficient antibacterial activity against both Gram-negative and Gram-positive bacteria. The highest zone of inhibition was observed against S. aureus MTCC 3160 (15.83 ± 1.1 mm), and for E. coli, P. aeruginosa PAO1, and B. subtilis, it was found to be 12.66 ± 0.9, 14.33 ± 0.8 and 12.8 ± 0.8 mm, respectively.