MgAl2O4:Ho3+ Nanophosphors: Electrochemical Sensor, Photoluminescence and Photocatalytic Applications

Ho3+-doped MgAl2O4 nanophosphors (1-11 mol%) was synthesised via solution combustion method using oxalyl dihydrazide (ODH) as fuel. The findings revealed a range of band gap energies (Eg) between 4.86 and 5.42 eV. It was confirmed that these values correspond extremely well with the experimental data using the DFT approach. The Ho3+ ions in the host undergo f-f transitions that are triggered at 406 nm and as a result, exhibit discrete photoluminescence emission peaks between 406 and 605 nm. Enhanced MgAl2O4 have CIE coordinates from orange-red to yellow region and 97% colour purity. Photocatalytic properties of nanophosphors under UV light led to the discovery that a rapid orange-red dye is activated at 493 nm. Removal of fast orange red (F-OR) dye using the new photocatalysts and MgAl2O4:Ho3+ nanophosphors has been demonstrated. The investigation showed that 89.02% of the dye lost its colour after being exposed to radiation for 120 min. The modified MgAl2O4:Ho3+ carbon paste electrode used in the cyclic voltametric (CV) technique for lead pollution detection. Based on their electrochemical performance, it is concluded that MgAl2O4:Ho3+ nanophosphors are a viable material for lead detecting electrodes.