Hierarchical electrospun nanofibers for energy harvesting, production and environmental remediation

As the demand for energy is rapidly growing worldwide ahead of energy supply, there is an impulse need to develop alternative energy-harvesting technologies to sustain economic growth. Due to their unique optical and electrical properties, one-dimensional (1D) electrospun nanostructured materials are attractive for the construction of active energy harvesting devices such as photovoltaics, photocatalysts, hydrogen energy generators, and fuel cells. 1D nanostructures produced from electrospinning possess high chemical reactivity, high surface area, low density, as well as improved light absorption and dye adsorption compared to their bulk counterparts. So, research has been focused on the synthesis of 1D nanostructured fibers made from metal oxides, composites, dopants and surface modification. Furthermore, fine tuning these NFs has facilitated fast charge transfer and efficient charge separation for improved light absorption in photocatalytic and photovoltaic properties. The recent trend in exploring these electrospun nanostructures has been promising in-terms of reducing costs and enhancing the efficiency compared to conventional materials. This review article presents the synthesis of 1D nanostructured fibers made via electrospinning and their applications in photovoltaics, photocatalysis, hydrogen energy harvesting and fuel cells. The current challenges and future perspectives for electrospun nanomaterials are also reviewed.