Green synthesis of LiZnVO4 nanoparticles and its multiple applications towards electrochemical sensor, supercapacitor, humidity sensing, photoluminescence and antioxidant activities

LiZnVO₄ nanoparticles (NPs) were synthesized by a simple combustion method using Hibiscus Rosa Sinensis leaves as a novel fuel and the prepared NPs were characterized using XRD, FT-IR, morphological analysis by SEM and TEM studies, elemental analysis by EDAX and ICP-MS. XRD data of the synthesized NPs were well-matched with the JCPDS number 038–1332 and it confirms the distorted phenacite structure of LiZnVO₄. FT-IR strengthens the bonding of M-M and M–O in LiZnVO₄. Optical characteristics of LiZnVO₄ NPs were studied by photoluminescence (PL) spectroscopy. Vanadate group of the prepared NPs originates a green emission. Examination of latent finger prints (LFP’s) showed a crystal clear patterns under near UV region (365 nm) as they are the prominent techniques in crime investigations. LiZnVO₄ NPs exhibit a strong antioxidant property and act as a good sensor to detect sodium nitrite analyte at extremely low concentrations with limit of detection of 27.5 nM. Three-electrode system supercapacitor device has been fabricated and examined the performances. Specific capacitance of LiZnVO₄ NPs based supercapacitor was found to be 88.7 F/g at a current density of 0.1 mA. Power density (P_d) and energy density (E_d) were found to be 0.51 W/g and 12.3 Wh/Kg, respectively. This device exhibits a stable CV curves up to the scan rate of 10 V/s. Furthermore, LiZnVO₄ NPs acts as an excellent material towards the humidity sensing with a sensitivity factor, sensitivity and limit of detection of 28.0, 0.3 MΩ/%RH and 5%RH, respectively. All the above studies show the diverse potentiality of LiZnVO₄ NPs.