Recently, A group led by Prof. CHEN Jiping and Prof. ZHANG Haijun in the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences revealed the formation mechanism of highly toxic chlorinated aromatic compounds during solid waste incineration. Their findings were published in Environmental Science and Technology, and it was selected as the current Supplementary Cover.
　　A large number of aromatic compounds, such as benzene, phenol, biphenyl, polycyclic aromatic hydrocarbons and analogues, can be formed and emitted during solid waste incineration, accompanied by the formation and volatilization of chloride, chlorine and chlorine radicals.
　　In the incineration flue gas, these aromatic compounds can react with chlorine-containing species in a complex way to form chlorinated aromatic compounds, such as dioxins, polychlorinated biphenyls, polychlorinated naphthalene and chlorinated polycyclic aromatic hydrocarbons. These chlorinated compounds, which is known as their carcinogenic, teratogenic and mutagenic effects, have been partly listed as persistent organic pollutants by United Nations Environment Program. Therefore, their emission is specially monitored by environmental protection authorities.
　　Chlorination of aromatic hydrocarbons is a key step to control the formation of chlorinated aromatic compounds in incineration flue gas. Since too many substances and elementary reactions are involved, the formation mechanism of highly toxic chlorinated aromatic compounds during solid waste incineration has not been comprehensively and intensively understood, which limits the development of emission reduction technology of chlorinated aromatic compounds.
　　Dechlorination-oxychlorination cycles of Cu and Fe species drive naphthalene chlorination. (Image by WANG Dan and ZHANG Haijun)
　　The researchers investigated the effects of a series of metal oxides and chlorides, such as copper, iron, manganese, aluminum, chromium, nickel, etc., on the electrophilic chlorination of aromatics by simulating the reaction atmosphere of incineration flue gas and using naphthalene as a model compound.
　　“We found that copper and iron chlorides were the key active substances to promote the chlorination of naphthalene, and we revealed the mechanism of electrophilic chlorination of aromatic compounds driven by dechlorination–oxychlorination cycles of copper and iron species” said Prof. CHEN.
　　Copper chloride and ferric chloride could act as chlorinating agents to directly induce chlorination of aromatic compounds. In the dechlorination-oxychlorination cycle of copper species, the direct chlorination induced by copper chloride was the main mechanism of chlorination of aromatic compounds, while the direct chlorination and catalytic chlorination played the same role on the chlorination of aromatic compounds driven by dechlorination-oxychlorination cycle of iron species.
　　Based on the in-depth understanding of the chlorination mechanism of chlorinated aromatic compounds during solid waste incineration, the researchers developed a technology to inhibit the formation of chlorinated aromatic compounds such as dioxins from incineration sources, which has been applied in three large-scale municipal solid waste incineration power plants.
　　The above work was supported by DICP Innovation Fund the National Natural Science Foundation of China and the National Key Basic Research Development Plan (973). (Text by WANG Dan and ZHANG Haijun)

　　A research group led by WU ZhongShuai from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences developed high volumetric-energy-density and long-life lithium sulfur (Li-S) batteries based on the free-standing, densely compact, and integrated cathode.
　　These Li-S batteries are derived from three-dimensional (3D) interconnected porous graphene/CNT aerogels, simultaneously serving as sulfur host and interlayer. Their findings were published in Nano Energy.
　　Lithium-sulfur (Li-S) batteries, as one highly competitive alternative for commercially available high-energy-density lithium metal batteries, have drawn considerable attentions on account of high theoretical gravimetric and volumetric energy density.
　　However, the practical applications of Li-S batteries have been hampered by several issues, including low mass densities of nano sulfur, intrinsically poor electrical conductivities of sulfur, large volume expansion of sulfur particle during cycling, and shuttling effect of lithium polysulfide, all of which result in low volumetric energy density and limited cyclability of Li-S batteries.
　　Hence, improving the gravimetric and volumetric energy density at the same time, as well as prolonging the cycle stability of the Li-S batteries, is the bottleneck of the applied research of the Li-S batteries.
　　Schematic of 3D graphene/carbon nanotube aerogels for ultrahigh volumetric-energy-density lithium-sulfur batteries. (Image by SHI Haodong and HOU Xiaocheng)
　　The scientists developed a free-standing, compact, conductive and integrated cathode, constructed by compressing graphene/carbon nanotubes aerogels, simultaneously serving as bi-functionalities of binder- and metal-current-collector-free sulfur host and interlayer for Li-S batteries.
　　The integrated cathode displayed high compaction density, outstanding mechanical flexibility and high electrical conductivity, which could endow the cathode with ultrahigh volumetric mass density, volumetric-energy-density, and exceptionally long-term cycling stability with an extremely low decay rate over 500 cycles at 2C.
　　This proposed integration cathode strategy would open numerous opportunities for constructing binder-free, current-collector-free, high-sulfur-loading and compact cathodes toward high-volumetric-energy-density and flexible Li-S batteries.
　　This work was supported by National Natural Science Foundation of China, National Key R&D Program of China, Dalian National Laboratory For Clean Energy (DNL), CAS, etc. (Text by SHI Haodong and HOU Xiaocheng)

　　Recently, a research team led by Prof. LI Xianfeng, Prof. ZHANG Huamin, and Prof. ZHANG Hongzhang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences developed a new lithium/carbon fluoride battery with high energy density.
　　The lithium/carbon fluoride battery was tested by a third-party authority, the institute of Chemical Power for Light Industry. It reported that the energy density of the advanced 10Ah energy-type lithium/carbon fluoride battery could reach to 940 Wh/kg (1150 Wh/L), which rewrote the energy density record of analogue batteries.
　　The lithium/carbon fluoride battery had an extremely low self-discharge rate, long shelf life (more than 10 years), no electrolyte corrosion hazard and low work temperature (-40 °C). Therefore it presented a superior performance than lithium/thionyl chloride batteries.
　　Moreover, the advanced power-type lithium/carbon fluoride battery could achieve the high energy density of 550 Wh/kg at a discharge rate of 1C, demonstrating that it had great potential application value in the electronic devices field. (Text by CHEN Yuqing)

　　A research group led by Prof. LIU Shengzhong from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences improved the photovoltaic performance of inorganic perovskite solar cells (PSCs). Their findings were published in Advanced Energy Material and Nano Energy.
　　Schematic diagrams of SmBr3 modification at TiO2/CsPbIBr2 interface and Ba2+ doping in CsPbIBr2. (Image by WANG Kai and DUAN Lianjie)
　　Organic-inorganic metal halide perovskite solar cells have attracted extensive attentions due to their high power conversion efficiency (PCE). However, the perovskites usually exhibit poor stability due to the weak interaction between the organic cations and iodine-lead octahedrons, which restricts its further development for commercialization.
　　In contrast, all-inorganic perovskite materials (CsPbX3, X=I, Br) have become an emerging research subject due to their excellent thermal stability. However, due to the non-radiative recombination in PSCs based on inorganic perovskites, the photovoltaic performance still has a large room to improve.
　　In order to improve the PCE of inorganic PSCs, Prof. LIU adopted different strategies to suppress the non-radiative charge recombination in PSCs. In general, the non-radiative recombination in PSCs could be divided into two parts: interface recombination and non-radiative recombination in the perovskite layers.
　　For interface recombination, the researchers modified the electron transport layer/perovskite interface by using a lanthanide bromide and obtaining a gradient band structure at the interface, which inhibited the interface electron recombination successfully and enhanced the charge extraction as well. With this strategy, the PCE of CsPbIBr2-based PSCs was increased to 10.88%, representing a high level in this field.
　　In addition, barium ions were doped in CsPbIBr2 to suppress the inside non-radiative recombination. Although the radius of Ba2+ did not meet the requirements of the Goldschmidt rule, it could still optimize the optoelectronic properties of CsPbIBr2 and improved device stability.
　　This study showed that perovskite materials possessed a high tolerance to extrinsic metal ions.The above results provided a basis for the regulation strategy of inorganic perovskite and promoted the development of inorganic PSCs to a certain extent. (Text by WANG Kai and DUAN Lianjie)

　　A research group led by Prof. LIU Shengzhong from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences and Dr. XU Zhuo at Shaanxi Normal University (SNNU) developed a technique to prepare large size 2D perovskite single crystals to achieve highest photodetector performance among this type. Their findings were published in Matter.
　　The (001) plane presented the highest photodetectivity. (Image by LIU Shengzhogn)
　　Due to their promising stability and excellent optoelectronic properties, two-dimensional (2D) layered organic-inorganic hybrid perovskites have demonstrated better performance in certain applications than their three-dimensional (3D) counterparts. In particular, 2D perovskites show better performance in certain optoelectronic devices, especially ones fabricated on the (001) plane.
　　The scientists developed a surface tension-controlled crystallization method to prepare large 2D (C6H5C2H4NH3)2PbI4 ((PEA)2PbI4) perovskite single crystals (PSCs). Using this technique, they harvested some inch-sized 2D (PEA)2PbI4 PSCs with the largest reaching 36 mm in length, resulting in extraordinary device performance.
　　As predicted using the density function theory, their crystal structures show anisotropy-dependent optoelectronic performance. More specifically, the photodetectors fabricated on the (001) plane exhibit responsivity as high as 139.6 A/W, external quantum efficiency of 37719.6%, detectivity of 1.89 × 1015 cmHz1/2/W and response speed as fast as 21 micro second.
　　These results will provide a promising pathway for stable high-performance photodetectors and open a new avenue for commercialization of perovskite single crystals for photoelectronic applications.
　　The study was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, the National University Research Fund, and the 111 Project. (Text by LIU Shengzhong)

　　Recently, scientists from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences, in collaboration with Prof. LIN Sheng-Cai from Xiamen University and Prof. D. Grahame Hardie from the University of Dundee, discovered that hierarchical activation of AMPK depended on severity of nutrient or energy stress. Their findings were published in Cell Research.
　　A simplified model depicting that the differentially compartmentalized pools of AMPK are activated with different dependencies on AXIN, and the severities of nutrient or energy stress. (Image by WANG Wen and WANG Ting)
　　AMPK, a master regulator of metabolic homeostasis, is activated by both AMP-dependent and AMP-independent mechanisms. The conditions under which these different mechanisms operate, and their biological implications are unclear.
　　Depending on the degree of elevation of cellular AMP, the scientists found that distinct compartmentalized pools of AMPK were activated, phosphorylating different sets of targets.
　　Low glucose activated AMPK exclusively through the AMP-independent, AXIN-based pathway in lysosomes to phosphorylate targets such as ACC1 and SREBP1c, exerting early anti-anabolic and pro-catabolic roles.
　　Moderate increased in AMP expanded this to activate cytosolic AMPK also in an AXIN-dependent manner. In contrast, high concentrations of AMP, arising from severe nutrient stress, activated all pools of AMPK independently of AXIN.
　　These findings revealed a spatiotemporal basis for hierarchical activation of different pools of AMPK during differing degrees of stress severity.
　　This study was supported by National Natural Science Foundation of China and the Open Research Fund of State Key Laboratory of Cellular Stress Biology, Xiamen University. (Text by Wen Wang and WANG Ting)