“Developed nanoproducts are inspired by nature”. So say Musee, Foladori and Azoulay from the Council for Scientific and Industrial Research in the publication ‘Social and Environmental Implications of Nanotechnology Development in Africa’. For example, the leaf of a lotus has a surface of hydrophobic nanoparticles, which could be an inspiration for thin films that repel water. Similarly, lizard’s feet have nanohairs so small that they create forces of molecular attraction that help the animal stick to vertical surfaces and even defy gravity. Using these examples, nanomaterial deposition and inclusion has led to the design and construction of many hydrophobic (and hydrophilic), active and reactive materials and surfaces used widely in our everyday lives.
In an effort directed towards the development of technologies for harvesting energy from our living environment, such as solar energy, headway has been made in the design of technologies that mimic natural photosynthesis. The conversion of light into stored chemical energy by artificial photosynthesis, a chemical process which replicates natural photosynthesis, has been the focus of many recent studies. These energy systems are strongly dependent on the electronic and physical properties of the materials they are constructed from. Nanostructured materials are gaining increasing interest for application in artificial photosynthesis due to benefits of their large surface area, short lateral diffusion length, and low reflectivity. The ability to modify the structure of nanomaterials and to synthesise nanostructures of various morphologies may improve conversion efficiency in artificial photosynthesis applications.
A long-term goal is to construct a synthetic, photochemical system that converts solar energy into a storable fuel. Even though photovoltaic technology facilitates the direct generation of electricity from sunlight, it is incapable of efficiently producing fuel which can be stored and used in the absence of light.
Photoelectrolysis, or light-induced water splitting, converts water into hydrogen and oxygen through the use of sunlight. The hydrogen produced in this process provides a source of clean fuel. The use of multijunction configurations has been the predominant approach for the development of efficient photoelectrochemical water-splitting cells. Efforts have also been focused on new materials to enhance processes at both anodes and cathodes and the integration of photoelectrolysis cells with other structures.
Developing viable approaches for collecting and storing solar energy would have great impact on the mobile electronics industry. The overall power consumption of mobile electronic devices can be massive, even though, individually, the power consumption of these devices is relatively low. Presently, the powering of electronics still relies on rechargeable batteries. The number of batteries required to power our gadgets is increasing proportionately to the increasing number and density of electronics in use. Considering the modern technological trend of mobile devices and the rapidly growing industry, concerns are raised about potential environmental pollution caused by the batteries that power these devices and, therefore, the need for recycling or replacement of the batteries used today. New and viable means of harvesting and storing energy for use in electronic devices are needed. New solar technologies could effectively extend the lifetime of rechargeable batteries or even completely replace them.
The ability of artificial photosynthetic systems to convert harvested solar energy into fuel and store it in the system for later applications is crucial. Concerns of low photocatalytic efficiency and scaling up of the manufacturing process need to be resolved before artificial photosynthetic systems can be set up. It is crucial to develop artificial photosynthetic systems from natural materials in an affordable and environmentally friendly manner. It can be expected that artificial photosynthetic systems will play an important role in providing sustainable and clean energy.