Green, Nonchemical Route for the Synthesis of ZnO Superstructures, Evaluation of Its Applications toward Photocatalysis, Photoluminescence, and Biosensing

In the present work, we have developed a novel, ecofriendly method for the synthesis of ZnO superstructures for the first time through the thermal decomposition of zinc nitrate precursor without using any fuel. The synthesized materials were thoroughly characterized using various analytical tools such as X-ray diffraction, Fourier-transform infrared spectrometry, UV–vis, scanning electron microscopy, and transmission electron microscopy. Further, it has been used as a photocatalyst for the degradation of one of the environmental pollutants such as methylene blue and also as a biosensor toward the detection of dopamine at trace level. The as-synthesized ZnO nanoparticles showed superior catalytic activity toward the degradation of methylene blue dye with high degree of recyclability with yellow light emitting photoluminescence. The developed sensor showed a linear range for dopamine up to 300 μM with a detection limit of 1 μM with reproduced results over periods of several months without any deviation in its electrochemical performance.