Hamidu Ibrahim, Afotey Benjamin, Kwakye-Awuah Bright, Anang Daniel Adjah
Department of Chemical Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
Department of Chemical Sciences, University of Development Studies, Nyankpala Campus, Ghana.
Heliyon. 2025 Feb 5;11(4):e42491. doi: 10.1016/j.heliyon.2025.e42491. eCollection 2025 Feb 28.
A lot of attention has been drawn to environmentally friendly and sustainable materials in the need to decarbonize the planet. The utilization of agro-waste to meet this need has increased in recent times. Among the various agro-wastes, rice husk has gained more traction due to its abundance, unique constituents, and properties suitable for advanced material synthesis. Precursor materials such as silica and silicon used in advanced materials synthesis are also synthesized from rice husk. The synthesis of these advanced materials depends on the rice husk pretreatment and thermochemical conversion approach. Pretreatment methods such as acid leaching generally yield higher silica purity compared to water leaching. However, the use of acid in leaching impurities during pretreatment leads to the release of harmful chemicals. Among thermochemical methods used in silica synthesis, the hydrothermal method has gained more attention due to the use of water as a liquid medium and the elimination of the raw materials drying step, reducing emissions and energy demand in the process. Metallothermic reduction methods such as magnesiothermic and aluminothermic reduction of silica to silicon have attracted much attention due to their low reduction temperature. This review discusses the composition and properties of rice husk and its thermochemical conversion to silica (SiO) and silicon (Si). Silica and silicon are essential materials used as framework or precursor materials in the synthesis of other advanced materials such as zeolites and catalyst supports. The second part of the review discusses the various thermochemical conversion approaches and their kinetics. The final part of the review discusses the various rice husk-derived advanced materials and their applications.
在地球脱碳的需求下，环保和可持续材料受到了广泛关注。近年来，利用农业废弃物来满足这一需求的情况有所增加。在各种农业废弃物中，稻壳因其丰富性、独特成分以及适合先进材料合成的特性而更受关注。先进材料合成中使用的前驱体材料如二氧化硅和硅也由稻壳合成。这些先进材料的合成取决于稻壳预处理和热化学转化方法。与水浸相比，酸浸等预处理方法通常能获得更高的二氧化硅纯度。然而，预处理过程中使用酸浸出杂质会导致有害化学物质的释放。在二氧化硅合成中使用的热化学方法中，水热法由于使用水作为液体介质并省去了原料干燥步骤，减少了过程中的排放和能源需求而受到更多关注。金属热还原方法，如用镁热还原和铝热还原法将二氧化硅还原为硅，因其还原温度低而备受关注。本综述讨论了稻壳的组成和性质及其热化学转化为二氧化硅（SiO）和硅（Si）的过程。二氧化硅和硅是合成其他先进材料如沸石和催化剂载体时用作骨架或前驱体材料的重要材料。综述的第二部分讨论了各种热化学转化方法及其动力学。综述的最后一部分讨论了各种源自稻壳的先进材料及其应用。
