Carbon nanosheets coated on zirconium oxide nanoplate nanocomposite for Zn2+ ion adsorption and reuse of spent adsorbent for fingerprint detection

다국어 초록 (Multilingual Abstract)

This work highlights a novel method for the synthesis of carbon nanosheets coated on zirconium oxide nanoplate (CNS/ZrO2NPs) nanocomposite that is used as an adsorbent for Zn2+ ions removal from water. CNS/ZrO2NPs nanocomposite was prepared using CNS and ZrO2NPs by a hydrothermal method. This nanocomposite proved to be a good adsorbent for Zn2+ ion uptake at maximum pH of 8 and dosage of 20 mg. The Temkin isotherm model represented the adsorption process followed by the Langmuir isotherm with a maximum adsorption capacity of 606.06 mg g−1, above other adsorbents that have been reported for the removal of zinc ions. The adsorption kinetic process was best described by the pseudo-second-order kinetics, and it was found that the adsorption followed a chemisorption process. The thermodynamic parameters, such as enthalpy (ΔH), Gibbs free energy (ΔG), and entropy (ΔS), revealed that the adsorption was exothermic, spontaneous, and not random during the process. This metal-loaded adsorbent Zn2+-CNS/ZrO2NPs nanocomposite furthermore was reused in latent fingerprint detection and did demonstrate good selectivity and sensitivity on different surfaces by two donors. Therefore, Zn2+-CNS/ZrO2NPs nanocomposite may be reutilized as a good fingerprint marking agent in latent fingerprint (LFP) identification to circumvent secondary environmental pollution by the release of a spent adsorbent.