Janus structure is composed of two or more components with different (usually opposite) physical and chemical properties. Janus nanoparticles possess multiple surface structures that are anisotropic in shape, composition, and surface chemistry.
　　Janus nanoreactors have been applied in the fields like catalysis, biomedicine, as well as energy storage and conversion. However, it remains a challenge to construct Janus nanoreactors with stable interfacial structure.
　　Recently, a research team led by Prof. LIU Jian from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences, in collaboration with Prof. HU Ming from East China Normal University, reported a novel and simple strategy for the synthesis of dual-component Janus nanoreactor with asymmetric structure to realize bifunction of photocatalytic water oxidation/reduction.
　　This work was published in Advanced Science on Feb. 16.
　　A: schematic illustration of the synthetic strategy for the PBA–TiO2 Janus nanoreactor, B: TEM images of the as-prepared PBA-TiO2 Janus nanoreactors C: comparison of photocatalytic H2 evolution and O2 evolution rate of TiO2, PBA, PBA–TiO2 Janus nanoreactors and PBA–TiO2 (mix) samples under light irradiation (Image by SHI Chunjing)
　　"We mimics the concepts of compartmentalization used by nature to design PBA-TiO2 Janus photocatalysts for coordinating incompatible chemical transformations," said Prof. LIU.
　　In the synthesis process, the partial dissociation of the PBA cube was induced by mild etching. The unsaturated metal sites on the PBAs could form the chemical bond with oxygen ions and Ti4+, inducing heterogeneous nucleation of TiOx on the surface of the PBA single crystals.
　　Free-standing flowers assembled by TiO2 nanoflakes took root in the PBA single crystals. The PBA-TiO2 Janus nanoreactor gradually emerged and the asymmetric dual-components of nanoreactor possessed a synergistic effect due to the presence of the interfacial structure.
　　The forming interfacial structure could promote the fast charge transport and effectively inhibit the photogenerated electron and hole recombination. The photocatalytic activity of PBA-TiO2 Janus nanoreactor for water oxidation/reduction was significantly higher than that of pure TiO2 and PBA catalysts.
　　The above work was supported by the National Natural Science Foundation of China, and Dalian National Laboratory for Clean Energy (DNL) Cooperation Fund, Chinese Academy of Sciences. (Text by SHI Chunjing)

　　A degeneracy or conical intersection occurs in many of the experimentally relevant ultracold (T < 10-3 kelvin, 1 kelvin = -273.15°C) reaction systems, resulting in a geometric phase (GP) that modifies many of the ultracold reaction rates.
　　Due to its potential application in controlling ultracold chemistry, the so-called GP effects have attracted lots of attention. However, the mechanism of GP effects in ultracold reaction process remains uncleared.
　　Recently, a research ream led by Prof. ZHANG Dong Hui from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences unveiled the nature of GP effects in the ultracold chemical reaction for the first time.
　　Their results were published in The Journal of Physical Chemistry Letters on Feb. 26.
　　Mechanistic insights into Uultracold chemical reactions under the control of the geometric phase (Image by HUANG Jiajun)
　　The researchers calculated the time-independent scattering wave function of the ultracold O + OH → H + O2 reaction using the newly developed time-dependent wave packet (TDWP) dynamical method.
　　The analysis of the total scattering wave function revealed the nature of the quantum interference and associated GP effects in this ultracold reaction process for the first time. And this wave function analysis can be generalized to other ultracold reactions that contain a conical intersection.
　　This study offers a new way for providing mechanistic insight for the dynamics and control of ultracold chemical reactions. (Text by HUANG jiayu)

　　Ogataea (Hansenula) polymorpha, a representative methylotrophic yeast, can efficiently assimilates methanol, and thus is considered as a promising chassis host for efficient methanol biotransformation.
　　However, difficulties in convenient and precise genome editing in O. polymorpha limits its metabolic engineering toward industrial application.
　　Recently, a research group led by Prof. ZHOU Yongjin from the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences achieved efficient genome editing in methylotrophic yeasts.
　　They developed novel genetic tools for precise genome editing in O. polymorpha by enhancing high homologous recombination (HR) rates, and revealed a strong competition between HR and non-homology end joining (NHEJ).
　　With this efficient tool, O. polymorpha was harnessed for the first production of fatty alcohols from both glucose and methanol.
　　This work was published in iScience on Feb. 9.
　　Recombination machinery engineering for precise genome editing in methylotrophic yeast Ogataea polymorpha (Image by GAO Jiaoqi)
　　CRISPR/Cas9 system was constructed and optimized by fine regulation of Cas9 and expression of sgRNA, which achieved efficient genome edition with positive rates up to 90% Then the dynamically regulation of key gene KU80 in NHEJ pathway and enhanced expression of HR-related proteins (Rad51, Rad52, Sae2) increased HR rates to 60~70%.
　　"This HR up-regulated systems has been applied for scarless gene deletion, homologous integration of large fragments and in vivo assembly of multiple fragments, which enables the first production of fatty alcohols in O. polymorpha," said Prof. ZHOU.
　　This study was supported by National Natural Science Foundation of China, Dalian Science and Technology Innovation Funding, DMTO and BioChE-X Research Grant of DICP, CAS. (Text by GAO Jiaoqi)

　　Photoelectrochemical (PEC) water splitting is an ideal approach for renewable solar fuel production. Tantalum nitride (Ta3N5) has a theoretical solar to hydrogen conversion efficiency of 15.9%, but it is not stable in the highly oxidative environment of water oxidation.
　　Ferrihydrite (Fh) could be used in modifying Ta3N5 photoanode for highly stable water oxidation reaction. However, the intrinsic structure responsible for the hole storage function for Fh remains unclear.
　　Recently a research team led by Prof. LI Can from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences unveiled the hydration structure of ferrihydrite for hole storage based on tantalum nitride photoanode system.
　　Their results were published in Angew. Chem. Int. Ed. and selected as hot paper.
　　Unveiling the hydration structure of ferrihydrite for hole storage in photoelectrochemical water oxidation (Image by WANG Pengpeng and SHI Jingying)
　　The researchers demonstrated that the irreversible and gradual loss of crystal water molecules in Fh led to the weakening of the hole-storage function, accompanied with the arrangement of inner structure units.
　　They proposed a structure evolution of the dehydration process and identified the primary active structure of Fh for HSL as the [FeO6] polyhedral units bonding with two or three molecules of crystal water.
　　Moreover, they found that with the successive loss of chemical crystal water, the coordination symmetry of [FeO6] hydration units underwent mutation and a more ordered structure was formed, causing the difficulty for accepting photogenerated holes as a consequence.
　　This study provides a new avenue for the rational design of efficient and stable solar water splitting devices based on interfacial modification strategies.
　　The research was supported by the National Natural Science Foundation of China and the Ministry of Science and Technology of China. (Text by WANG Pengpeng and SHI Jingying)

　　Hydrogen bonds (HBs), the main intermolecular interactions, are inherently fluctuant in nature.
　　Elucidating the dynamic couplings of hydrogen bonds remains challenging for spectroscopic studies of bulk systems, because their vibrational signatures are masked by the collective effects of the fluctuation of many hydrogen bonds.
　　Recently, a research team led by Prof. JIANG Ling from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences, in collaboration with Prof. ZHANG Zhaojun from DICP, Prof. KUO Jer-Lai from Institute of Atomic and Molecular Sciences (Taiwan), and Prof. LIU Zhi-Feng from Chinese University of Hong Kong, identified vibrational signature of dynamic coupling of a strong hydrogen bond.
　　The study was published in The Journal of Physical Chemistry Letters on Feb. 26.
　　The study revealed that dynamic couplings were originated from strong Fermi resonance between the stretches of hydrogen-bonded OH and several motions of the solvent water/methanol, such as translation, rocking, and bending. It also highlighted a general model to elucidate the dynamic coupling of hydrogen bond in atmospheric and biological systems.
　　Based on the infrared spectroscopy using a tunable vacuum ultraviolet free electron laser (VUV-FEL), the research team unmasked the vibrational signatures for the dynamic couplings in neutral trimethylamine-water and trimethylamine-methanol complexes, as microscopic models with only one single hydrogen bond holding two molecules.
　　The broad progression of OH stretching peaks with distinct intensity modulation over ~700 cm-1 was observed for trimethylamine-water, while the dramatic reduction of this progression in the trimethylamine-methanol spectrum offered direct experimental evidence for the dynamic couplings.
　　Quantum mechanical calculations revealed that such dynamic couplings were originated from strong Fermi resonance between the stretches of hydrogen-bonded OH and several motions of the solvent water/methanol, such as translation, rocking, and bending. (Text by JIANG Shukang, SU Mingzhi, YANG Shuo, WANG Chong)

Oxidative dispersion has been widely used in the regeneration of sintered metal catalysts as well as the fabrication of single-atom catalysts.The consensus on the oxidative dispersion process includes the formation of mobile metal oxide species from large metal particles and the capture of these species on a support surface. Nevertheless, the mechanism of oxidation-induced dispersion has yet to be confirmed via in situ electron microscopic and/or spectroscopic characterizations.Recently, a research team led by Prof. FU Qiang and Prof. BAO Xinhe from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. YANG Bing from DICP and Prof. GAO Yi from the Shanghai Institute of Applied Physics of CAS, reported the oxygen adsorption-induced dispersion of metallic Ag nanoclusters in a typical oxidative atmosphere.The results were published in Nature Communications on March 3.Dynamic evolution of Ag nanostructures during oxidative dispersion (Image by LI Rongtan）By utilizing in situ imaging methods such as environmental scanning electron microscopy (ESEM), and newly developed near-ambient pressure photoemission electron microscopy (NAP-PEEM), researchers found that micron-scale Ag nanowires could be dispersed into subnanometer clusters under an oxygen atmosphere.Ex situ experiments indicated that Ag nanowires were converted into AgOx nanoclusters. Conversely, in situ near-ambient pressure photoelectron spectroscopy (NAP-XPS) directly demonstrated the presence of a transitional state of metallic Ag nanoclusters during dispersion at high temperatures, while the formation of the oxide occurred during the cooling process. The dynamic dispersion of Ag nanowires during CO oxidation was also demonstrated.Based on experimental and theoretical calculations, chemisorption of oxygen from the O2 atmosphere was shown to be the essential driving force for the dispersion of metallic Ag nanoclusters.This work provides a new understanding of the role of the O2 atmosphere in oxidative dispersion, which is particularly important for the prediction and control of the dynamic dispersion/redispersion of supported metal catalysts under similar reaction conditions.This work was supported by the National Natural Science Foundation of China, the Strategic Priority Research Program (B) of the Chinese Academy of Sciences, the Ministry of Science and Technology of China, and the DNL Cooperation Fund. (Text by LI Rongtan)