Nanotechnology in Solar and Biofuels

The daunting energy challenges in the 21st century are a result of over-reliance on limited fossil fuels coupled with ever-increasing energy demand. Among the solutions is the development of technologies and infrastructures to help in the smooth transition to alternative and renewable energy sources. Nanotechnology, a combination of chemistry and engineering, is viewed as the new candidate for clean energy applications. It involves the manipulation of nanoscale structures to integrate them into larger material components and systems. In comparison to bulk materials, nanomaterials have high surface areas and are expected to exhibit higher activities. They also demonstrate better stability and durability and are more cost-effective with high recycling potential. This paper reviews selected recent advances in the development of nanotechnology in the emerging solar energy and biofuel fields. Special emphases are given to studies on photovoltaics (including Schottky junction solar cells, organic solar cells, quantum dot-sensitized solar cells, and earth-abundant Cu2ZnSnS4 materials) and artificial photosynthesis. As for the biofuel section, a review on the use of nanotechnology in transesterification, gasification, pyrolysis, and hydrogenation, as well as in the reforming of biomass-derived compounds is given. As these technologies become more mature, efficient, and economical, they could eventually replace traditional fossil fuels.