---an economical hydrogen catalyst is invented
DU Pingwu’s group from University of Science and Technology of China designed an extraordinary catalyst can split water into hydrogen with visible light. The materials is based on the fantastic nanotechnology leading to remarkable yield and lower cost. This achievement was published as a cover paper on Energy and Environment Science from renowned Royal Society of Chemistry (RSC) with the title "
Extraordinarily efficient photocatalytic hydrogen evolution in water using semiconductor nanorods integrated with crystalline Ni2P cocatalysts"on Sept 1st, 2015.
As fuel resources shortage become more and more serious, develop recycle energy becomes the urgent affair for both scientists and governments. Hydrogen is an ideal candidate for its high energy density and nontoxic product-water only-compared to greenhouse gas fuel generates. However, the traditional manufacture method of hydrogen is electrolysis of water. This is an inefficient craft. Meanwhile, modern photocatalytic method needs precious metal as catalyst. The high cost result in huge obstruction for population. Another bottleneck constrain is low yield for catalyst system itself. The nonuniform distribution of catalyst and cofactor cut down lifetime of photoelectron.
DU’s group devotes to cut down the cost of photocatalytic hydrogen system, which is constituent of earth-abundant elements only. After excited by light, semiconductor CdS generates free electron. Usually, the active electron is absorbed by noble metal, such as Platinum. They are so expensive that it’s impractical to apply the technology to industry. Fortunately, phosphide transition metal like nickel phosphide (Ni2P) also has similar character. It can promote the separation of electron and hole. The active electrons reduce the water and generate hydrogen before captured by system. DU develops a kind of heterogeneous nanorods to make sure high stability as well as large surface area. The crystalline Ni2P anchors onto one-dimensional CdS with solvothermal reaction.
As reported to date, the catalytic rate of the DU’s noble-metal-free system has been ahead of the world. When system is excited at 450nm, the apparent quantum yield reached ~41%. One milligram material can produce 1200umol hydrogen per hour. More than 3 million time reaction take place in 90 hours.
With intriguing efficiency and low-cost, DU’s system has huge potential to satisfy increasing global demand for clean and recycle energy. Pollution problem can be solved at the same time. World we are living will be changed dramatically by scientists’ innovative breakthrough.
(Betty YAN, USTC News Center)
