From geothermal sources to advanced applications: A review of sustainable silica nanomaterials

Silica nanomaterials derived from earth-abundant element – one of which is from geothermal powerplant waste, have become the focus of researchers and industries in recent years. Due to different synthetic conditions and chemical treatments, the adjustable morphology, structure, and surface chemistry, these sustainable nanomaterials offer vast applications. The possibility of producing silica nanomaterials from natural sources, such as waste and low-cost minerals, also accounts for their great prospect. This review reports various synthesis techniques and their effect on the physical properties of silica nanomaterials from geothermal sludge, in particular to that from Indonesia’s geothermal powerplant. The surface chemistry section discusses the interface chemical properties which leads to various surface modifications. We further discuss the application of silica geothermal-based nanomaterials in a plethora of different fields, including forensic, sensing and biosensing, heterogeneous catalysts and constructions. The prospect of these materials and their circular economy analysis was also discussed. This review will provide necessary information for the advanced production of sustainable silica nanomaterials.