Abolition and turning stones into gold Qingda University Professor Ling Yongjian uses green chemistry to promote circular economy
5G commercial transfer is coming soon. When technology giants are launching new 5G mobile phones one after another and countries are intensively deploying base stations to lay out the layout for the next communication era, the world has to face up to the environmental pollution caused by communication chips. 5G communications can be successfully unveiled, and "gallium arsenide" is the biggest contributor behind it. The material properties of "gallium arsenide" allow electrons to move faster, and it is a chip raw material for making mobile phone power amplifiers (PA); however, "arsenic" in it is also a century-old poison that causes cancer and is harmful to the environment. Arsenic was used to kill people in ancient times. Blackfoot disease is also caused by arsenic contaminating water quality. During the manufacturing process of communication wafers, if arsenic-containing wastewater or waste oil is not properly treated, arsenic will enter the groundwater system through weathering and dissolution, causing pollution. In the age of communications, dealing with arsenic pollution has become a global issue. The research team of Professor Ling Yongjian of the Department of Chemistry of Tsinghua University, who has long been specialized in green chemistry methods, separated arsenic from "waste cutting oil" containing gallium arsenide through "wet smelting[1]", and the processed "non-toxic cutting oil" "It can be purified and turned into a synthetic raw material for "carbon quantum dots" in vivo imaging detection reagents. By turning waste oil into products of high economic value, Ling Yongjian's team successfully turned stone into gold and achieved the goal of resource reuse. Using green chemistry methods to solve chemical pollution, investing in green chemistry, and promoting the recycling of waste resources were not the main focus of Ling Yongjian’s early research. After graduating from the United States in 1989, he returned to China to teach at Tsinghua University. He was engaged in research on "analytical chemistry" and often cooperated with organizations such as the Environmental Protection Agency and the Consumer Council to apply mass spectrometry analysis.