CityUHK JC STEM Lab of Circular Bio-economy has recently made a major breakthrough. Led by Professor Lee Duu-Jong, the team developed two innovative technologies for sustainable development.
The first is an all-weather “building skin” inspired by nature. This bio-inspired coating cools buildings in sunlight and harvests energy from rain. It is paintable and easy to apply, making it suitable for retrofitting existing buildings. In sunny weather, the coating reflects over 95% of solar energy. It also emits stored heat as infrared radiation, lowering surface temperatures by up to 9.5°C. During rain, water droplets trigger electrical pulses.
These pulses can power small devices like LCDs or sensors. The layered design is inspired by the Tillandsia air plant. The outer layer handles water contact and self-cleaning. The inner layers reflect sunlight, dissipate heat, and store charges. This design ensures high efficiency without trade-offs.
The second breakthrough is an eco-friendly hydrogen system. Developed by postdoctoral fellow Dr. Mak Chun Hong, it replaces costly platinum with abundant copper ions. This allows continuous hydrogen production using simple energy sources like a smartphone flashlight. Copper ions create a self-regenerating cycle.
They form a “copper hydride” state, storing energy under light and releasing hydrogen in the dark. Professor Lee calls this a “chemical turbocharger.” The system can produce green fuel 24/7 at low cost. It offers a scalable solution for clean energy needs.
These innovations support Hong Kong and the Greater Bay Area’s energy resilience. They also promote resource circularity in dense urban environments. Professor Lee said the lab will continue translating research into practical applications. Collaborations with industry aim to develop low-carbon, smart cities. This aligns with China’s 15th Five-Year Plan and Hong Kong’s Climate Action Plan 2050.
