As fuel resources shortage become more and more serious, developing recycle energy has become an 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 which 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 will cut down lifetime of photoelectron.

DU Pingwu’s group from University of Science and Technology of China of Chinese Academy of Sciences designed an extraordinary catalyst which can split water into hydrogen with visible light. The materials are based on the fantastic nanotechnology leading to remarkable yield and lower cost. This study entitled "Extraordinarily efficient photocatalytic hydrogen evolution in water using semiconductor nanorods integrated with crystalline Ni2P cocatalysts" was published on Energy and Environment Science from renowned Royal Society of Chemistry (RSC).

The researchers devoted to cutting down the cost of photocatalytic hydrogen system, which is constituent of earth-abundant elements only. After excited by light, semiconductor CdS can generate free electron. Usually, the active electron is absorbed by noble metals, such as Platinum. They are expensive that it’s impractical to extend the technology into industry. Phosphide transition metal like nickel phosphide (Ni₂P) has similar character. It promotes the separation of electron and hole. The active electron reduces the water and generates hydrogen before captured by system. DU's team developed a kind of heterogeneous nanorods to assure high stability and large surface area. The crystalline Ni₂P anchors onto one-dimensional CdS with solvothermal reaction.

The catalytic rate of the researchers’ noble-metal-free system is a world leader. When system is excited at 450nm, the apparent quant yield reaches ~41%. One milligram material can produce 1200umol hydrogen per hour. More than three 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 can be solved at the same time. The world we are living in will be changed through scientists’ innovation.