Recently, the 2017 undergraduate students, Ye Xiaoling and Zhang Minliang et al, from the School of Space Science and Physics investigated Raman spectral features of H2O2 under simulated Martian conditions and built aquantitativemethodfor future Martian H2O2-H2O solution and H2O2-mud mixtures. Related results were published online in Journal Raman Spectroscopy (2021, DOI: 10.1002/jrs.6227; IF: 3.13), titled “Using Raman spectroscopy to identify spectral features of and detect hydrogen peroxide-potential application for Mars exploration”, where Ye Xiaoling and Zhang Minliang are the first co-authors and their supervisor Professor Wu Zhongchen from the School of Space Science and Physics of Shandong University is the corresponding author.
As is known, Mars is the most earth-like planet in the solar system, and it is very possible that biological phenomena have been existing or have ever appeared. At present, China "Zhurong" Mars rover has completed its scheduled exploration missions. Mars became the first planet for China to step out of the Earth-Moon system and enter the planetary system, which is also a current international research focus. There are strong UV radiations in Martian atmosphere and on the Martian surface. Thin gaseous H2O2may be produced by UV photochemical reactions which has been detected by remote sensing methods of Martian orbiters (ppbV level). And its abundance depends on the abundant variation of atmospheric water vapor and seasons.
H2O2is a well-known peroxide and oxidizing agent with disinfectant, antiviral and anti-bacterial activities. Therefore, the identification and detection of H2O2on Martian surface is important to better understand the Martian surface environment and explore extraterrestrial life. However, no one knows so far whether H2O2exists on current Mars surface or not. In what form does it exist? What kind of impacts do the H2O2have on the living/organic substance on Mars? These questions are important and remain to be resolved.
Raman spectroscopy has been regarded as “an important instrument for the next generation of exploration of the key Martian organisms, minerals, rocks and soil samples.” Two Raman payloads of NASA, SuperCame and SHERLOC, were installed on Perseverance rover and successfully loaded on Mars Jezero Crater on Feb. 18, 2021 which provides the potential hardware for H2O2detecting on the surface of Mars.
In view of this, the 2017 undergraduate Ye Xiaoling and Zhang Minliang of the School of Space Science and Physics, under the guidance of Prof. Wu Zhongchen, used the Mars chamber of institute of space science to design several experiments under simulated Martian conditions, using fiber laser Raman spectroscopy to (1) analyze the spectral features of an H2O2-H2O solution and H2O2-mud mixture under ambient laboratory conditions and low-temperature conditions,(2) build a quantitative detection model and investigate the LOD (Limit of detection) of H2O2in aqueous solutions and mud matrixes with typical Martian mineral simulants, and (3) investigate the photodegradation characteristics of H2O2under UV radiation. Experiment results show that H2O2has a remarkable Raman peak at 877cm-1, which is distinguishable from H2O and other minerals, making it easy to detect with an LOD of 400 ± 50 ppm in an H2O2solution and 1666 ± 450 ppm in a kaolinite matrix (2000 ± 500 ppm in a gypsum matrix). There was no peak shift and only a certain degree of reduction in the intensity for this peak in an H2O2solution under low temperature, even for frozen H2O2. The spectral features facilitate the detection and identification of H2O2on the Martian surface. Our study provides valuable information about the Raman detection of H2O2on Mars.
The result was published in The Journal of Raman Spectroscopy (IF: 3.13).
Figure 1: Raman spectrum characteristics of H2O2 under low temperature conditions (A: H2O2 short-wave region spectrum; B: H2O2 long-wave region spectrum; C: H2O long-wave spectrum data for comparison)
The planetary science research team were supported by the "Academic Discipline Peak Program" and the "Solar Burst and Its Impacts on the Planetary Space Environment" Climbing Program of Shandong University to build a Mars chamber which serves for scientific research and undergraduate/graduate training. The Institute of Space Science and the School of Space Science and Physics attach great importance to the cultivation of undergraduates' scientific research and innovation ability. The work is an important achievement for Students Ability Raise.
Paper publication link:
https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/10.1002/jrs.6227