A research team led by HAN Keli from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences synthesized undoped and Ag-doped lead-free double perovskite nanocrystals (NCs) by variable temperature hot injection. Ag-doped NCs exhibited bright yellow emission, and the dynamics mechanism was further clarified. Their findings were published in Angew. Chem. Int. Ed..
　　Lead-free halide perovskite NCs have drawn wide attentions and become a hot topic of current research due to non-toxicity and stability. In particular, indium-based double perovskite NCs with three-dimensional structure and direct bandgap are considered to be the ideal light emitting materials in the illumination field.
　　However, the photoluminescence quantum efficiency (PLQE) of undoped In-based NCs is still very low since the mechanism is unclear. This problem restricts the design and development of new and efficient perovskite materials.
　　PL spectrum and HRTEM image of the Cs2NaInCl6:10% Ag NCs. (Image by HAN Peigeng)
　　The scientists synthesized high-quality undoped and Ag-doped lead-free direct bandgap Na-In-based double perovskite NCs by novel variable temperature hot injection. This method was universal for lead-free perovskites NCs.
　　Scientists found that the Cs2NaInCl6 NCs had little photoluminescence attributed to dark self-trapped excitons (STEs). And the doping Ag+ cations could not only make a transition from dark STEs state to bright STEs state, but also passivate defects. Thus, the Cs2NaInCl6: Ag NCs exhibited bright yellow emission with the highest PLQE of 31.1% and excellent stability.
　　The STEs dynamics mechanism was further studied through ultrafast transient absorption (TA) techniques.
　　This work highlights the importance of synthesis method optimization and proper element doping for the design of new semiconductor NCs, and provides a new and feasible way to search for new high-performance nano materials in optoelectronic applications.
　　This study was supported by the key research project of National Natural Science Foundation. (Text by HAN Peigeng)

　　Metabolic analysis involves ongoing biological pathways and can be more distal than proteomic/genomic approaches to in vitro diagnostics (IVD). However, point-of-care (POC) metabolic analysis needs special designed materials to detect target biomarkers of low concentration in complex biosystems.
　　Schematic workflow of the multifunctional Pt platform. (Image by HUANG Lin)
　　Scientists from Shanghai Jiao Tong University, University of Surrey and the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) have developed a multifunctional platinum (Pt) nanoreactor geared towards POC metabolic analysis that performs visual detection and mass spectrometry (MS) fingerprinting simultaneously. Their findings were published in Matter on October 2.
　　The Pt nanoreactor was designed with a controlled core-shell structure and morphology for the visual detection of metabolic biomarkers and direct laser desorption/ionization MS fingerprinting of the native serum. The molecular mechanism of efficient catalytic processes only takes 5 min for visual quantitation of metabolic biomarkers was also investigated. In particular, the platform enabled biopsy-free diagnosis of pancreatic cancer patients with a sensitivity of 84% and specificity of 92%.
　　The scientists further identified a potential panel of five biomarkers, which may shed light on progression monitoring in response to therapy.
　　"It is a minimally invasive, high throughput and fast platform, improving accessibility to disease diagnosis," said Prof. QIAN Kun.
　　"This development of on-site and on-time diagnostics based on these nanoreactors may enhance the performance of POC devices geared towards personalized medicine and diverse diseases in the near future," Prof. LIU Jian added. (Text by HUANG Lin)

　　Illegal drug smuggling has long been a global concern and has posed a serious threat to human health. Recently, the sharp increase of fentanyl overdose deaths has been declared a national crisis in the North American.
　　A group led by Prof. LI Haiyang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences, in collaboration with Yunnan Police Officer Academy, and Drug analysis and Drug Control Technology Key Laboratory of the Ministry of Public Security, developed a rapid screening of trace volatile and nonvolatile illegal drugs by miniature ion trap mass spectrometry, realizing the rapid on-site detection of illegal drugs in mixtures and the minimum detectable quantity reach to 50 picograms for fentanyl. The study was published in Anal. Chem..
　　The group has been working on the rapid detection of illegal drugs. Acetone assisted photoionization was introduced and a temperature-resolved thermal desorption sampling strategy was developed to distinguish illegal drug mixtures in 10 minutes, 27 kinds of illegal drugs has been detected as well.
　　However, the illegal drugs usually have a distinct boiling point, and nonvolatile illegal drugs has a low detection sensitivity while the volatile illegal drugs have a short detection period. In order to faster identification the illegal drug mixtures with big difference of boiling point, flash-thermal-desorption was used to thermal desorb the sample and its focal temperature can reach to 290 ℃ in 2.5 seconds which could achieve more than 60 times improvement in sensitivity compared with the previously reported miniature ion trap for nonvolatile drugs.
　　The synchronized purging and ion injection with DAPI could accurately control the time interval along with the desorption, gas purging, ionization and ion injection, and the sample utilization ratio increased more than 5 times. ten kinds of mixing drugs with boiling point difference of 300 ℃ could be simultaneously identified within 3 seconds.
　　 
　　Left: Photo of the mass spectrometer applied at a frontier inspection station in Yunnan province. Right: Schematic diagram of the synchronized flash-thermal-desorption purging and ion injection and the on-site identification of fentanyl capsule. (Image by WANG Weimin)
　　During the development process, the mass spectrometer has been used in multiple Frontier Inspection Stations in Yunnan provinces, such as Mukang Frontier Inspetion Station in Dehong Autonomous Prefecture, Qinglongchang Frontier Inspection Station in Yuxi city, and so on. 37 kinds of illegal drugs’s mass spectrum has been added into the identification’s database and valuable experience was gained for the study of ion trap mass spectrometry in drug detection.
　　The above research was supported by the national natural science foundation of China. At the same time, it is also one of the articles dedecated for the 70th anniversary of DICP. (Text by Weimin Wang)

　　Recently, a research group led by Prof. TIAN Peng and Prof. LIU Zhongmin from the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences (CAS) summerized the progress in methanol-to-olefins (MTO) catalysts. The study was published in Advanced Materials.
　　MTO reaction and its industrial plant over zeolite catalyst. (Image by YANG Miao)
　　Methanol conversion to olefins provides an alternative platform for producing basic chemicals from nonpetroleum resources such as natural gas and coal. MTO catalysis is one of the critical constraints for the process development, reactor design, and profitability of the process.
　　After the construction and commissioning of the world's first MTO plant by DICP based on high-efficiency catalyst and fluidization technology in 2010, more attention has been attracted for a deep understanding of the reaction mechanism and catalysis principle, leading to the continuous development of catalysts and processes.
　　The scientists summarized recent progress in MTO catalyst development, focusing on the advances in the optimization of SAPO-34 catalysts, together with the development efforts on catalysts with preferential ethylene or propylene selectivity.
　　Based on the above work, the research team developed new generation of DMTO catalysts, realized its industrial production in October 2018, and successfully applied the new catalyst to DMTO commercial plant, showing significant improvement in yield of light olefins.
　　This work was supported by the National Science Foundation of China and the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences. It was dedicated to the 70th anniversary of Dalian Institute of Chemical Physics, Chinese Academy of Sciences. (Text by YANG Miao)

　　Recently, a research group led by Prof. JIANG Peng and Prof. BAO Xinhe from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) reviewed the progress of photodetectors based on the photothermoelectric effect. And this article was published in Advanced Materials.
　　Schematic of PTE conversion process, and the summary of the application fields of PTE effect. (Image by LU Xiaowei)
　　Photodetectors operating in the long wavelength infrared (LWIR, 8 - 14 μm) and terahertz (30 μm - 3 mm) ranges have important applications. Photothermoelectric detectors, which combine the photothermal and thermoelectric processes, can be utilized to realize the room-temperature detection of LWIR and terahertz radiations in the self-powered mode. The high-performance photothermoelectric detectors are playing more important role in the LWIR and terahertz detection.
　　This review summarized the recent advances in the photothermoelectric detectors based on the low dimensional materials, bulk porous materials and organic materials. The strategies, such as surface plasmon, phonon absorption, and optical antenna, to enhance the interaction between light and matter and then improve the performance of photothermoelectric detectors were highlighted.
　　Furthermore, the applications of photothermoelectric effect in the investigation of novel physical phenomena in the near-field optics, spintronics and valleytronics were introduced. And the promising research direction of photothermoelectric detectors was envisioned.
　　This work was supported by the National Key Research and Development Program of China and Dalian Institute of Chemical Physics. It was dedicated to the 70th anniversary of DICP, CAS. (Text by LU Xiaowei)

　　Scientists from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Scientists (CAS), collaborated with Tsinghua University and Arizona State University, revealed a much more pronounced water promotional effect on CO oxidation on Au single-atom sites than on interfacial sites of Au nanocatalyst due to their different local atomic structures and electronic properties. The results were published in Nature Communications.
　　Scheme illustration of single-atom sites and interfacial sites of nanocatalyst (above); Different water promoting effect on CO oxidation on single-atom catalysts and nanocatalyst (below).
　　Supported metal catalysts have played a central role in the modern chemical industry. The synergy between a support and supported metal is often critical in determining the performance of catalysts because the interfacial perimeter sites in many cases serve as the dominant active sites.
　　Heterogeneous single-atom catalysts (SACs), consisting of isolated metal single atoms dispersed onto a support, maximize the number of interfacial perimeter sites and are expected to provide unique opportunities for catalyzing chemical transformations. However, due to the quantum size and ensemble effects of metal clusters and particles, and the differences between SACs and nanocatalysts in electronic and support effects as well as metal support interaction, it is still an open question whether the active sites in SACs possess similar catalytic properties to those of the interfacial sites in supported metal NPs or cluster catalysts.
　　In this work, scientists discovered that CO oxidation on the single-atom sites was dramatically promoted by the presence of water whereas on interfacial sites of nanocatalyst the promoting effect was much weaker.
　　Computational modeling based on density functional theory (DFT) revealed that the significant difference in the water promoting effect originated from the different active-site structure and electronic properties between Au single atoms in the Au SAC and the interfacial Au atoms in supported Au NP catalysts.
　　The positively charged, non-zero valent Au atom in the Au1/CeO2 SAC was more variable in oxidation states as an electron acceptor, which offered a more efficient channel for the CO and OH reaction pathway with the presence of OH groups (or water molecules). In contrast, the near zero-valent Au interfacial atoms in supported Au NPs did not seem to favor such oxidation state change, thus significantly hindering the CO and OH reaction pathway.
　　This work not only offers an avenue to develop highly efficient catalyst for CO oxidation with the presence of water by fabricating suitable single-atom catalysts, but also provides an example to understand the difference between SAC and the interfacial sites in supported metal NPs or cluster catalysts. (Text by CHEN Fang)