For prize winner, tiny things are a big thing

UNESCO honors Chinese chemist and professor with science award for women

A Chinese scientist has been named one of the five winners of this year's UNESCO Women in Science Awards for her work on nanomaterials.

The awards, sponsored by the French cosmetics company L'Oreal, were presented in Paris on March 18.

Each of the five winners represented a region, with Xie Yi earning honors in the Asia-Pacific. The other winners were: Thaisa Storchi Bergmann of Brazil, representing Latin America; Carol Robinson of Britain, Europe; Molly Shoichet of Canada, North America; and Cherkaoui El Moursli of Morocco, Africa and the Arab states.

The awards are presented to outstanding women scientists "for their groundbreaking discoveries in the physical sciences".

"Each of these women is a brilliant example of scientific excellence," a UNESCO statement said. "They prove every day that women can greatly contribute to scientific progress in a field still largely dominated by men."

Xie, 48, is a chemist and professor at the University of Science and Technology of China in Hefei, capital of Anhui province. She is also a member of the Chinese Academy of Sciences.

She has made "significant contributions to creating new nanomaterials with promising applications in the conversion of heat or sunlight into electricity", UNESCO said.

Xie has spent her career looking for new ways of dealing with problems such as energy security and pollution.

She and other researchers at the university work with unconventional materials only a few atoms thick, known as two-dimensional nanomaterials, in order to maximize the use of electrons to convert energy more efficiently.

"The materials now used to produce or transfer energy, such as the semiconductors that harvest solar energy to generate electricity, are surprisingly inefficient," Xie says. "Much of the energy, carried by electrons, is lost along the way.

"Rather than traveling directly to reach reaction molecules or device electrodes, the electrons bump into each other or onto the material. This causes energy carriers to be destroyed, and unnecessary and destructive heat to be generated."

The new ultra-thin materials that Xie's team is experimenting with are designed to reduce such energy loss by optimizing surface structures. They are also far more efficient in harvesting and converting energy sources than conventional materials, pushing energy use to the limit.

"The aim of our work is to reduce human dependence on ever scarcer fossil fuels, to lessen pollution and boost energy utilization efficiency," Xie says.

"We have been able to harvest solar energy to generate chemical energy or convert waste heat into electricity, which may take the efficient conversion of solar energy and waste heat a step further."

Such efficient use of solar energy and waste heat is "the most important way of reducing our dependence on fossil fuels and cutting down pollution", she says.

Xie's "reputation as a professor and mentor is on par with her reputation as a researcher", UNESCO said. "She has won nearly as many prizes for excellence as an educator as she has for her scientific achievements."

Xie began to win these national and international honors when she started working at the University of Science and Technology of China in the late 1990s.

Some of them were exclusively for women, such as the Chinese Young Women in Science Fellowship in 2006, while others were for all comers, such as the Chinese Academy of Sciences Graduate Adviser Award in in 2005, 2008, 2009, 2013 and 2014.

"The L'Oreal Foundation and UNESCO have played important roles in promoting women scientists in scientific research," Xie said in a speech at the awards ceremony.

A lot needs to be done to reach gender balance in science, she has said. In a speech last year she said about half the students in Chinese universities are women, but that of the 21 million researchers in the country, only about 40 percent are women.

UNESCO says only 30 percent of the world's researchers are women, and that many obstacles discourage women from entering or pursuing a career in science.

Xie says discrimination against women in science is often barely perceptible.

"I would like to encourage young people, both men and women, to follow their hearts and find their true interests in science," she said in Paris.

zhulixin@chinadaily.com.cn

(China Daily Africa Weekly 03/27/2015 page30)