EXPERIMENTAL INVESTIGATION OF THE PHOTOPHYSICAL PROPERTIES OF OPTIMIZED NANO-SILICA DERIVED FROM DIFFERENT WEIGHTS OF RICE HUSK

Abstract

The effect of the initial starting weight of rice husk (RH) on the photophysical properties of nano-silica (RHS) has been explored. The nano-silica was produced by pretreating RH with acids and subsequent thermal treatment. The analysis of surface morphology revealed that all the samples contained agglomerates of spherical nanosized particles, with larger particles produced from higher starting weights of rice husk. The optical properties of the RHS are due to more than one defect or center, including oxygen-deficiency centers (ODCs), non-bridging oxygen holecenters (NBOHC), and carbon impurities. The emission color of the RHS samples shifts from blue to near-white light as the weight of the starting RH increases due to an increase in the carbon residue left in the samples. This nano-silica is ideal for use in photonics and other engineering applications.