This article reports the synthesis and purification of nanosilica (SiO₂) derived from the husk of some rice varieties; Faro-44, Faro-46, Faro-52, Nerica-I, and Nerica-II. The husks were pretreated with H₂O and HCl. From the measurement results, Nerica-I rice husks produced the highest silica yield and best photophysical properties. Thus, the husks of Nerica-I rice were further pretreated with H₃PO₄ to additionally remove more mineral impurities and the derived nanosilica labeled nSiO₂ was selected to serve as a host matrix for doping with varying concentrations of Sm³⁺ions. The doped nanosilica (nSiO₂:xSm³⁺; x = 0.01, 0.05, and 0.1 molar ratios) maintained the amorphous structure of the undoped nanosilica, while the surface morphology as revealed by SEM and TEM indicates agglomerates of spherical nano-sized particles with average particle size measuring 21 nm. The Sm³⁺-doped nanosilica shows a large surface area measuring 198.0 m²/g. The photoluminescence excitation spectra show that near UV and blue LEDs can effectively be used as excitation sources to produce yellow and yellow-green emissions from Sm³⁺ ion-doped nSiO₂ suitable for display applications.

中文翻译：

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几种稻壳壳化纳米SiO _2的结构和光学性质及Sm ³⁺离子掺杂的影响

本文报道了从一些稻壳中获得的纳米二氧化硅（SiO ₂）的合成和纯化。Faro-44，Faro-46，Faro-52，Nerica-I和Nerica-II。稻壳用H ₂ O和HCl预处理。从测量结果来看，Nerica-I稻壳产生了最高的二氧化硅产量和最佳的光物理性质。因此，将Nerica-I稻壳进一步用H ₃ PO ₄进行预处理，以另外去除更多的矿物杂质，并选择衍生的纳米二氧化硅标记的nSiO ₂作为基质以掺杂不同浓度的Sm ³⁺离子。掺杂的纳米二氧化硅（nSiO ₂：x Sm ³⁺; x＝ 0.01、0.05和0.1摩尔比）保持未掺杂的纳米二氧化硅的非晶结构，而通过SEM和TEM显示的表面形态表明球形纳米尺寸颗粒的团聚，其平均粒径为21nm。掺杂了Sm ^3+的纳米二氧化硅显示出198.0 m ² / g的大表面积。光致发光激发光谱显示，近紫外和蓝光LED可以有效地用作激发源，从适合显示应用的Sm ³⁺离子掺杂nSiO ₂产生黄色和黄绿色发射。