Nanomaterials for Energy and Water Management

The limited supply of safe energy and clean water in spite of the growing demand of an expanding population constitutes a global challenge. Shell forecasts the global energy demand to triple from 2000 to 2050, in view of the projected growth in socioeconomic trends and popular demand. According to the 2013 Budapest Water Summit, it is expected that, by 2030, some 40% of the world's population will suffer from freshwater shortages. On the other hand, more than 50% of the total energy produced is estimated to be wasted, in the form of untapped available energy and inefficient energy usage. Meanwhile, the shortage of water is not due to its unavailability per se but the lack of its usable form. Much of the clean water used becomes polluted, which then prohibits its direct recycling without prior treatment. Therefore, the energy and water resources that are being wasted due to poor efficiency and management are a range of realizable “low hanging fruit”, compared to generating them as new. In this case, the development of new strategies by proper technological design to harvest energy or to treat water and to conserve existing resources will make our planet more sustainable. Singapore has a vibrant energy and water industry, which produces and transforms energy and water for the supply to all sectors in a competitive and intense economy. With limited natural resources, Singapore's energy and water challenges are multi-faceted. Innovation through collaborative research is one of the strategies to seek long-term solutions and resilience readiness. In the framework of addressing global energy and water challenges, we seek to deploy feasible or novel ideas that will be translated into technology adoption in energy and water management. The unique chemical and physical properties of nanomaterials provide opportunities for us to increase the efficiency of energy harvesting and conservation, as well as in the water sensing and remediation domain. Advanced nanomaterials not only outperform conventional bulk materials structurally with superior properties such as toughness, hardness, durability, and elasticity, but also functionally in terms of their ability to respond to a wider spectrum of changes, as well as providing new affinities or desirable properties to a given substance that are absent in its bulk state. For example, nanomaterials for thermoelectrics can have high electrical properties and low thermal conductivity at the same time due to quantum size effects and favorable carrier scattering mechanisms. In order to reflect the research effort in this direction, we are delighted to organize and present this special issue of Small with the topic “Nanomaterials for Energy and Water Management”. This issue contains five review articles, one concept paper, four communications, and three full papers. The content of these papers covers a broad range of nanomaterials for energy and water technology, including the rational design of nanomaterials for energy storage and conversion devices with enhanced performance, plasmonic nanomaterial-assisted solar energy harvesting, nanoparticles for the optical reading of contaminants in aqueous media, and nanocarbon materials for water remediation. All these projects are funded by the National Research Foundation (NRF), Prime Minister's Office, Singapore, under its Campus for Research Excellence and Technological Enterprise (CREATE) programme. It is worth noting that progress in this field is impossible without cross-fertilization between the chemistry, materials science, physics, engineering, and biology communities. While seeking pathways to tackle sustainable growth in the evolving global milieu, the importance of nanomaterials research provides a solid ground that deepens interdisciplinary creative solutions and initiates a spiral of innovations. We hope that this issue will provide stimulating highlights on the design, fabrication, and exploitation of novel nanomaterials for energy and water management. Efficient methods for harvesting, storing, and converting solar energy, producing electricity from waste heat, customized energy and water management, remote water monitoring, and low-cost water remediation will be several key directions to be addressed with the advancement of nanomaterials. Finally, we are most grateful for the invaluable support and professional editing from the whole editorial team of Small, in particular Dr. Jose Oliveira and Dr. Emily Hu. We would also like to express our gratitude to Ms. Zhongjing Jian and Mr. Bowen Zhu for the design of the front cover page, and DP Architects (Singapore) for the photograph featuring the CREATE campus. Last but not least, we are greatly indebted to our colleagues, who have contributed their research outcomes in this exciting and explorative volume of nanomaterials for energy and water management. Pooi See Lee is an Associate Professor in the School of Materials Science and Engineering, Nanyang Technological University (NTU), Singapore. She obtained her PhD at the National University of Singapore. Her research focuses on the theme of electrochemically and electrically tunable devices based on nanostructures and nanocomposites, for application in energy storage, electrochromics, electrical memory devices, and nanowire transistors or sensors. She currently is appointed as the Associate Chair of the School of Materials Science and Engineering (NTU). Xiaodong Chen is a Nanyang Associate Professor and Singapore National Research Foundation (NRF) Fellow at the School of Materials Science and Engineering, Nanyang Technological University (Singapore). He received his B.S. degree (Honors) in Chemistry from Fuzhou University (China) in 1999, M.S. degree (Honors) in Physical Chemistry from the Chinese Academy of Sciences in 2002, and PhD (Summa Cum Laude) in Biochemistry from University of Muenster (Germany) in 2006. After his postdoctoral fellow work at Northwestern University (USA), he started his independent research career at Nanyang Technological University in 2009. He was promoted to Associate Professor with tenure in September 2013. His research interests include integrated nano–bio interfaces and programmable materials for water remediation and energy conversion.