Dr. Ouyang Shuxin’s group published an article in the international top journal in the field of chemistry, Journal of the American Chemical Society

Recently, Dr. Ouyang Shuxin’s group, an affiliate of TU-NIMS Joint Research Center leaded by Prof. Ye Jinhua who is expert of The Thousand Talents Plan, published an article titled “Constructing solid-gas-interfacial Fenton reaction over alkalinized-C3N4 photocatalyst to achieve apparent quantum yield of 49% at 420 nm” in the international top chemical journal, Journal of the American Chemical Society. (A link to the paper: http://pubs.acs.org/doi/abs/10.1021/jacs.6b07272)

In the photocatalytic degradation of organic pollutanta typical advanced oxidation process (AOP), efficient generation of active oxygen-related radicals plays an essential role in boosting its activity. Fenton reaction can effectively generate oxygen-related radicals (hydroxyl radical •OH and superoxide radical •OOH) via the reaction between Fe2+/Fe3+ pair and H2O2. The method has been widely used in the research and industrial application of removing the pollutants in water and soil. In the photo-Fenton reaction coupling with Fe3+, Fe2+ and photocatalyst, the photocatalytic process generates H2O2, and then ferric ions trigger Fenton reaction, which produces sufficient oxygen-related radicals. However, the relevant application has mainly been focused on removing the pollutants in solution and soil. Few studies report the application of Fenton/photo-Fenton reaction in the elimination of gaseous pollutants, because efficient Fenton reaction strongly depends on the proper acidity of solution. Usually, gaseous pollutants in air are concentrated by bubbling gaseous pollutants into water, and further removed with Fenton's reagent, which is cumbersome and energy-consuming.

Our work reports alkalinized g-C3N4-based photocatalyst with Fe3+ loading to construct solid−gas interfacial Fenton reaction which can produce considerably abundant oxygen-related radicals to participate photocatalytic reaction. This photocatalytic system exhibits highly efficient and universal activity for photodegradation of volatile organic compounds (VOCs) including isopropanol, acetaldehyde, acetone, acetic acid and Toluene. Taking the photooxidation of isopropanol as model reaction, this system achieves a photoactivity of 2−3 orders of magnitude higher than that of pristine g-C3N4, which corresponds to a high apparent quantum yield (AQY) of 49% at around 420 nm. So far, it sets the new record of AQY among the reported g-C3N4-based photocatalysts for contaminant degradation. The significant photoactivity enhancement could be ascribed to the efficient and synergetic utilization of photoelectrons and photoholes to produce abundant oxygen-related radicals, which is the innovation of photocatalytic material and photochemical reaction path. Specific mechanism can be summarized to a three-step cascading reaction to generate reactive radicals (such as ·OH and ·O2) as following: (1) the surface hydroxyl groups are activated by photoholes to generate hydroxyl radicals which oxidize VOCs to produce protons; (2) the O2 and protons evolve into H2O2 via a two-photoelectron reduction process; (3) the Fe2+/Fe3+ pair reacts with the H2O2 to provide oxygen-related radicals. This study provides the most sufficient and convincing evidence for solid−gas interfacial Fenton reaction for the first time. And the strategy of coupling solid−gas interfacial Fenton process into semiconductor-based photocatalysis provides a facile and promising solution to the remediation of air pollution via solar energy.

TU-NIMS Joint Research Center is one of international collaboration platforms of our school, which aims at promoting international communication and cooperation, enhancing the standards of innovation research of multi-disciplinary crossing research including material chemistry, physics, energy, environment, etc, and training or jointly training research talents with international view and first-rate research accomplishment. The first author of the paper published in the JACS is postgraduate student Li Yunxiang, and he will go to National Institute for Materials Science (NIMS), Japan to study for a Doctor’s degree under the joint program between NIMS and Hokkaido University after graduation.