The division of Young Researchers was introduced. This division organizes interdisciplinary workshops in a format that facilitates learning for students and young researchers, and online schools focusing on the fundamentals of research for students. In this special issue, the recent research achievements have been introduced by young researchers and lecturers at the previous workshop. The presented topics cover photoinduced force microscopy and optical force mapping, electrochemistry and spectroscopic measurements of metalloenzymes, many-body interactions of biomolecules with water and ions, and ammonia combustion catalysts. This special issue also contains a tutorial article of the EMPeaks and an article on how to write a popular science book.

To fully understand the physics of chiro-optical systems and to derive their potentials, it is essential to observe chiro-optical effects in situ from individual components, since the macroscopic chiro-optical effects cannot be directly translated into the microscopic effects. Here, we observed optical responses at the nanoscale level by detecting optical forces induced by irradiating circularly polarized light onto a tip-sample system. The induced optical forces were well correlated with the differential intensity of the simulated electric field.

Redox-active metalloproteins including metalloenzymes play important roles in denitrification, photosynthesis and respiration. To understand their enzymatic reaction mechanisms and the effects of reaction environments on protein properties, protein film electrochemistry (PFE) coupled with surface-enhanced infrared absorption (SEIRA) spectroscopy is a powerful technique. Herein, we present and discuss PFE–SEIRA spectroscopy results on the determination of reduction potential, formation processes of bilayer lipid membranes on the electrode surface, and effects of protein-protein or protein-lipid interactions on the enzymatic activities for transmembrane metalloenzymes of cytochrome c-dependent nitric oxidase and cytochrome c oxidase.

Viewing interfacial molecular environments is of great importance to develop novel functional materials and to understand atmospheric, catalytic, and electrochemical reactions. Due to development in the lasing instruments and optical techniques in the past 20 years, the interface-specific vibrational spectroscopy, i.e., sum-frequency generation spectroscopy (SFG), has become a power tool to access such interfacial molecular structures. Here, I illustrate that heterodyne-detected SFG can provide quantitative interfacial property and molecular picture, and also can identify interfacial species from the interfacial waters’ structure with recent examples.

Ammonia (NH₃) is a renewable and carbon-free energy source. However, it has a high ignition temperature and produces N₂O and NO, which limit its use as a fuel. In this study, the combustion of NH₃ over copper oxide (CuO_x) and platinum (Pt) catalysts supported on aluminum silicate (3Al₂O₃·2SiO₂), aluminum oxide (Al₂O₃), and silicon oxide (SiO₂) was compared to overcome these issues. The synthesis conditions for the preparation of impregnated binary catalysts were optimized to achieve high catalytic activity for facilitating NH₃ combustion and high N₂ selectivity (or low N₂O/NO selectivity). Sequentially impregnated CuO_x/Pt/Al₂O₃ exhibited higher catalytic activity, N₂ selectivity, and thermal stability than binary catalysts.

There are a wide variety of measurement techniques that produce spectra as output datasets. Existing data analysis software and some open-source macros are useful but not sufficient for non-experts to perform peak-fitting analysis and interpretation. Therefore, we have investigated analysis method using unsupervised machine learning for high-throughput and automated peak deconvolution analysis of spectra without prior knowledge of experimental techniques and material databases. In this paper, we will introduce the open-source package called “EMPeaks”, including development chronology, specific usage, current issues, and analysis examples.