Abstract
Nanoparticles have versatile applications including environmental remediation, water treatment, pollutant detection, etc. In this work citrate functionalized Ag decorated citrate-Co NPs (cit-Co@Ag) prepared by chemical reduction method. XRD pattern reveals the possibility of crystalline Agshell@Cocore formation. FTIR spectra confirm the citrate capping on Co@Ag NPs and TGA carried out to study the NPs thermal stability. BET analysis indicates the mesopores present with narrow pore size distribution. The plasmonic-based Co@Ag NPs exhibited excellent photocatalytic performance with no photo-corrosion even after 6th recycles. Scavengers study reveals the major role of O2− radicals and e− on dye degradation. The cit-Co@Ag NPs probe was also applied in an effective colorimetric sensing technique to detect Cr(III) from aqueous samples. New complex formation of Cr(III)-cit-Co@Ag induces variation from yellow to pink color with the formation of a second band in absorbance spectra. The LOD of Cr(III) by the probe was 15 nM. The probe works under acidic pH and at a wide temperature range effectively. Interference studies revealed competitive ions did not affect Cr(III) detection. Further, the probe was also used for Cr(III) separation via altering solution pH to 11. The environmental samples with Cr(III) were analyzed and the accuracy of the probe was ensured by AAS analysis. In addition, cit-Co@Ag NPs showed high bacterial growth inhibition of both gram positive (B. subtilis) and gram negative (E. coli) bacteria indicate the multifunctional property of the prepared probe.
•Citrate functionalized Ag@Co bimetallic NPs were synthesized by chemical reduction method.•Cit-Ag@Co NPs showed excellent detection towards Cr(III) at nanomolar level.•Presence of other metal ions did not interfere with the detection of Cr(III).•Effect of environmental factors including pH, temperature and salinity on Cr(III) detection was also investigated.•The cit-Ag@Co bimetallic NPs exhibited good photocatalytic and antibacterial activities.