Photoluminescence and structural properties of air‐reduced rare‐earth (Eu) doped calcium silicates derived using biomass wastes

Abstract This study aimed to present an effective method of utilizing widely available biomass wastes to synthesize visible light‐emitting phosphors. Rice husk ash and egg shell powder were used to synthesize x(%) = 0.25, 0.50, 0.75, and 1.00 phosphors using a solid‐state reaction method. The prepared samples were characterized by various techniques. X‐ray diffraction data confirmed the stabilization of the phase at room temperature. X‐ray photoelectron spectroscopy (XPS) results indicated that ions underwent partial reduction to in the air atmosphere during the processing of the samples. X‐ray photoelectron spectroscopy also confirmed the presence of titanium ions in the synthesized samples. Titanium was present in trace amounts in biomass wastes. The photoluminescence emission spectrum contained high‐intensity bands because of titanium ions. Low‐intensity emission bands were also present in the photoluminescence emission spectrum due to the characteristic transitions of Eu. The coordinates of the waste‐derived samples could be tuned for different applications in the visible region because of the presence of multiple activator ions. The optical band gap of the samples as prepared was in the range 3.62–3.79 eV. This approach presents a method for preparing biomass waste‐derived phosphors that can be used for solid‐state lighting applications. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd