This talk will focus on passive radiative cooling and solar-driven water desalination technologies and the issues that have hindered their development for real-life applications. Our goals are to improve buildings’ energy efficiency by reducing the need for traditional vapor-compression cooling systems and enhance freshwater production by taking advantage of renewable energy. Part 1: The compressor-based cooling systems, providing comfortable interior environments for infrastructures, account for about 20% of the total electricity consumption around the world. Moreover, the resultant heating effect and greenhouse gas emissions towards the environment accelerate global warming and climate change. An energy-efficient and eco-friendly cooling approach is highly demanded. The emerging passive daytime radiative cooling (PDRC) technique can achieve sub-ambient cooling effects under direct sunlight without any energy consumption by simultaneously reflecting sunlight and radiating excessive heat as infrared thermal radiation to the cold outer space through the Earth’s atmospheric window. Such an approach is becoming an attractive candidate for improving energy efficiencies for buildings because it eliminates the need for coolant, electricity, and compressor required by traditional mechanical cooling systems. Part 2: Interfacial solar steam generation is emerging as a promising technique for efficient desalination. Although increasing efforts have been made, challenges exist for achieving a balance among a plethora of performance indicators—for example, rapid evaporation, durability, low-cost deployment, and salt rejection. We have demonstrated that carbonized agricultural waste can convert 98% of sunlight into heat, and the strong capillarity of porous carbon fiber networks pumps sufficient water to evaporation interfaces. Salt diffusion within microchannels enables quick salt drainage to the bulk seawater to prevent salt accumulation. These advantages, together with facial deployment, offer an approach for converting farm waste to energy with high efficiency and easy implementation, which is particularly well suited for developing regions.
Professor Zheng is an Associate Professor in the Mechanical and Industrial Engineering Department, Director of Nano Energy Laboratory at Northeastern University, and Founder and President of a cleantech startup Planck Energies. He received his PhD and MS from Columbia University and BS from Tsinghua University, all in Mechanical Engineering. Prof. Zheng has secured external funding from diverse sources totaling over $3M including multiple federal agencies NSF, NIH, NASA, DARPA, ONR, US Air Force, as well as industrial funding from 3M, MassVentures, and Soleeva Energy. Professor Zheng has published 70+ papers in high-quality journals such as Nano Energy and Advanced Functional Materials. He holds 4 PCT/US patents and 2 US patents pending.
Professor Zheng’s research interests fall in the areas of cleantech and sustainability technologies and he aims to address the growing global challenges in energy and water scarcity. His achievements are reflected in the prestigious honors and awards that he has received for his research, including the ASTFE Early Career Researcher Award, NSF CAREER Award, NIH RI-INBRE Early Career Development Award, 3M NTFA Award, Soleeva Energy Innovation Award, and MassVentures Acorn Innovation Award. His innovative cleantech research about green cooling and water desalination technologies has received tremendous global attention (e.g., US, UK, China, India, New Zealand and South Africa) and has been covered by more than 100 news outlets, including BBC, Science, ASEE Prism Magazine, India Times, Global Leaders Today, The Vanguard (GE News), and The Hill’s “Changing America.”
Event Date: April 6, 2023