A review on titanium oxide nanoparticles modified metal-organic frameworks for effective CO2 conversion and efficient wastewater remediation

Pollution of the environment due to air and wastewater have been disturbing a phenomenon for decades. Pollutants such as carbon dioxide (CO2), dyes, pharmaceuticals, phenols, heavy metals along with many organic and inorganic species have been discovered in the various environmental compartments. Studies have shown their negative impacts on human health, wildlife, and ecosystems. Thus, various efforts have been made through regulations, technological advancements, and public awareness campaigns to reduce the impact of the pollution. However, finding suitable alternatives to mitigate their impacts remained a challenge. Metal-organic frameworks (MOFs) are one of the advanced materials with unique features such as high porosity and stability. Recently they have found versatile applications in environmental remediation. Their composites with titanium oxide nanoparticles (TiO2) have been discovered to offer potential feature than the pristine form such as light harvesting capacity and catalytic activity. The composite integration and properties have been confirmed through characterization using surface area analysis, scanning electron/transmission electron microscopy, atomic force microscopy, fourier transformed infrared spectroscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy, thermogravimetric analysis, and others. Thus, this work rigorously discussed potential applications of the MOF@TiO2 nanomaterials for the CO2 capture and effective utilization to in methanol, ethanol, acetone, acetaldehyde, and other useful products that served as fuel to various industrial processes. Additionally, the work highlights the effective performance of the materials towards photocatalytic degradation of both organic and inorganic pollutants. Mechanisms for the stated processes have been illustrated. As such, it is hoped that the article will offer significant contribution for the development of sustainable and efficient technologies for the environmental monitoring and pollutions mitigation.