Research at FAST

18 Plasmonic Nanohole Array for Enhanced Photocatalytic Activity with Visible Light Plasmonic resonance of noble metal nanoparticles can boost wide-bandgap photocatalysts’ visible response. However, 2 fundamental obstacles limit the energy efficiency of visible photocatalysis: narrow absorption band and low absorption. Dr Xuming Zhang's team have developed a plasmonic black absorber that sandwiches a 150 nm TiO 2 layer between a random Au nanoparticles l a y e r a nd a r ough Au surface (200 nm thick). This enables strong absorption ( 7 2 % – 9 1% ) o v e r 400 – 900 nm and enhanced photocurrent (by 20 folds), making it an ideal material for solar photocatalysis and photothermal systems. Department of Applied Physics Composite Multilayers Capacitors with Colossal Permittivity for Electronics and Energy Storage Applications Global energy storage demands are growing rapidly, driving worldwide research efforts to develop capacitors to achieve faster charging, higher power density and longer cycling lifetimes than conventional batteries. Prof. Jianhua Hao’s team has won the TechConnect Global Innovation Award for flexible composite capacitors based on metal-ion co-doped colossal permittivity materials. Their innovation is the first to simultaneously achieve: large dielectric constant (i.e. large energy storage ability); negligible dielectric loss (i.e. resistance to energy leaks and wastage); and high energy density. The relatively simple and low cost process enables mass production of composite films, as ceramic powder fillers are fabricated by the conventional solid-state sintering method. Easily patterned, multi-layered capacitors with fully solid-state construction are superior to conventional electrochemical construction in many aspects including safety. Artificial Synthesis of Carbohydrates from CO 2 Using Microfluidic Reactors Famine and food shortages due to the extreme weather, land shor t ages and rapidly increasing population threaten humanity. The low activity and poor specificity of D-ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), in green food production crops is the main limitation inhibiting growth through natural photosynthesis (NPS). Recent work of Dr Xuming Zhang's team demonstrates the continuous artificial photosynthesis of glucose precursor from CO 2 and ribulose-1,5-bisphosphate (RuBP) with high stability and efficiency by immobilizing RuBisCO into a microfluidic reactor. This can solve food shortage problems. Optofluidic Tunable Lenses for Aberration-Free Focusing and Diverging in-Plane Light Beams Fine control of light beams in a microfluidic system is vital for many applications such as input/output coupling, optical switching and optofluidic laser/light sources. However, current methods are often slow (~1s) and subject to aberations. Dr Xuming Zhang’s team have developed a new optofluidic tunable lens design to create a 2D refractive index gradient through external laser irradiation. Their design enables continuous tuning of focal length from initially infinite to a minimum of 1.3 mm within 200 ms and fast tuning, aberration-free focusing and it can be remotely controlled. It also allows the use of homogeneous fluids for easy integration with other optofluidic systems. Our Achievements