Few civilizations are as old and storied as China, a corner of the world rich with cultural traditions that trace back through the region’s history and into myth. The drinking of tea, for instance, traces its origins to the folk mythology of Shennong, the divine farmer who taught people the value of herbs before the dawn of history. The making of Xuan paper, also known as rice paper, is another illustration of a Chinese cultural tradition that, while not as rooted in ancient myth as tea is, has been refined for more than 1500 years. Following these traditional threads through the ages, it’s possible to see the refinement of these respective processes into the methodical and meditative practices that they have become today — where they have come to intersect with the age of the photon. Courtesy of Pixabay/ulleo. At Beijing Institute of Technology, researchers demonstrated a method that used green tea as a reducing reagent for synthesizing ammonia, which could make the process greener by enabling the use of solar energy instead of water to convert nitrate, a pollutant, to ammonia under ambient conditions. The method could therefore eliminate the traditional process’s contribution to water pollution. Currently, ammonia is synthesized through an energy- and resource-intensive process that, according to professor Bing-Jie Ni of the Centre for Technology in Water and Wastewater at the University of Technology Sydney, accounts for ~2% of global energy consumption and leads to high carbon dioxide emissions. The tea used in the study differed from the choice loose-leaf product that is used in the ceremony of gong fu cha (which translates as kung fu tea or “tea with great skill”). The researchers instead used green tea bags in a technique that, compared to conventional ammonia production methods, demonstrated a nearly threefold increase in photocatalytic reduction activity. Xuan paper, too, offers insights that could lead to advancements in modern-era applications, including in optics. While examining the microscopic structure of Xuan paper, researchers at the University of Science and Technology of China found the underlying mechanism behind the paper’s characteristics that make it a prized substrate of traditional painters and calligraphers. The researchers discovered that the paper is composed of interweaved nano- and microfibers that form a multiscale three-dimensional network that gives the paper its flexibility and durability. Inspired by the structure of the paper, the team created its own high-performance transparent film by assembling cellulose micro- and nanofibers into a multiscale structure. The structure endowed the film with properties similar to those of rice paper — strength, toughness, flexibility, and foldability, as well as high light transmittance and high-haze transparency. The film could see use in precision optics and flexible electronic devices, the team said. Ancient traditions that have been tested and refined over the course of centuries can continue to provide insights that lead to a future that is both more green and more technologically advanced.