📒 Heterogeneous catalysis by nanomaterials is a preponderance promising technology for the remediation of toxic pollutants in water and air. Recently, there have been tremendous efforts to fabricate highly photoactive heterogeneous catalysts with desirable properties suitable for these applications. The production of silica has mainly been based on the use of tetraethylorthosilicate or tetramethylorthosilicate which are undoubtedly expensive and perhaps hazardous precursors attracting the urgency to search for cost-effective precursors and simplified synthetic routes. Meanwhile, composites with superior properties such as high surface area, large porosities and recyclability tolerance are invariably in great demand. In this book, cost-effective precursors and simplified synthetic routes are exquisitely introduced. Sodium silicate and titanium oxychloride solutions are considerably less expensive precursors which can be an alternative replacement of hazardous metal alkoxide precursors. The synthetic route and consumption of inexpensive sources reported herein are fascinating and will promote large scale production and commercialization of the heterogeneous catalysts and biodiesel.