Quantum dots (QDs) were recognized by the 2023 Nobel Prize in chemistry. As mentioned by the Nobel committee, in addition to their well-established applications in display, QDs will find many more applications to benefit humankind. One long sought-after application is QD-lasing, which seems to be straightforward given the intense and color-tunable emission of QDs.Over the years, a number of core/shell heterostructured QDs (primarily CdSe-based core/shells) with impeded Auger recombination have been developed. These efforts have led to several milestones in the development of QD-lasing technologies, such as sub-single-exciton low threshold lasing, continuous-wave lasing, and electrically-driven amplified spontaneous emission. However, due to the large size (10 to 20 nm) of the Auger-suppressed QDs used in these studies, these devices almost exclusively lase in the red part of the spectrum. This limitation leaves technologically-viable blue QD-lasers remaining out of reach, despite blue lasers are crucial to laser-based display, printing, manufacturing, data recording, and medical technologies.Recently, Prof. WU Kaifeng's group and his coworkers from the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences have achieved stable blue lasing from a solution of low-toxicity colloidal QDs. The study was published in Nature Nanotechnology.The researchers developed very compact (7.8 nm) ZnSe/ZnS core/shell QDs, yet their gain lifetime was approaching one nanosecond, which was comparable to the best CdSe-based complex core/shell systems with diameters typically of about 20 nm. A crucial enabler to this success was the suppression of nonradiative Auger recombination by an unintentionally alloyed core/shell interface that smoothened the confinement potential. Due to the compact size (thus minimized scattering loss) and long gain lifetime, the researchers could handle these QDs just like laser dyes, demonstrating tunable and robust liquid lasing output from a Littrow cavity under excitation by solid-state nanosecond lasers."Beyond making a significant advancement in blue QD lasing, the liquid laser based on ZnSe/ZnS QDs offers many practical benefits,” said Prof. WU. “They don't contain toxic elements such as Cd and Pb, and hence are more compatible with real lifetime applications, and they exhibit stability against photodamage that far exceeds typical blue dyes, allowing for consistent output needing circulation systems.”Therefore, this blue liquid laser not only serves as a promising replacement of blue dye lasers for existing technologies, but it can also fill the "blue gap" of QD lasers using environmentally benign QDs for a multitude of emerging applications.

Fructose, the most common food sweetener, is widely used in processed sugary beverages, candies, and baked goods. Excessive fructose intake is closely associated with metabolic diseases like obesity, diabetes, and fatty liver. Epidemiological studies have also shown that excessive fructose consumption increases the risk of colorectal cancer. However, the mechanisms of fructose in the progression of colorectal cancer remain unclear.Recently, a research team of Prof. PIAO Hai-long from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with the research teams of Prof. BU Pengcheng from the Institute of Biophysics of CAS, and Prof. SHEN Xian from Wenzhou Medical University, have uncovered new mechanisms by how fructose inhibites the polarization of M1-type tumor-associated macrophages (M1-like TAMs), thereby promoting colorectal cancer development. This study was published in Cell Metabolism.Fructose promots promotes the progression of colorectal cancer through inhibition of the polarization of M1-like tumor-associated macrophages (Image by Huiwen Yan)The researchers found that, in contrast to hepatocytes (primary cells for fructose metabolism), the metabolic rate of fructose in macrophages was significantly slower. Using 13C-labeled fructose metabolic flux analysis and targeted metabolomics, they demonstrated that fructose likely inhibited the polarization of M1-like TAMs through hexokinase 2 (HK2) rather than its downstream metabolic products.Furthermore, the researchers revealed that fructose promoted the interaction between HK2 and inositol 1,4,5-trisphophate receptor type 3（ITPR3）, a key protein component of Ca2+ transport channels in the endoplasmic reticulum. This interaction significantly reduced the formation of mitochondria-associated endoplasmic reticulum membranes (MAM) and decreased the concentration of calcium in the cytoplasm and mitochondria. Knocking out glucose transporter 5（GLUT5）or supplementing a mutational HK2 in bone marrow-derived macrophages with reduced HK2 expression reversed the downregulatory effects of fructose in MAM and calciumlevel.Additionally, the researchers observed that the interaction between HK2 and ITPR3 lowered calcium levels in mitochondria and cytoplasm, suppressing the activation of p38 mitogen-activated protein kinase (p38 MAPK) and signal transducer and activator of transcription 1 (STAT1), and NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome. This inhibition ultimately blocked M1-like TAM polarization."Our study reveals a novel role of fructose as a signaling molecule that promotes colorectal cancer by inhibiting M1-like TAMs polarization," said Prof. PIAO.

Microdroplets exhibit a remarkable ability to accelerate chemical reactions and initiate redox processesthat are typically challenging to achieve in bulk phase. However, the underlying mechanisms governing electron transfer at the microdroplets interface remain unclear.Recently, a research group led by Prof. WANG Feng and Assoc. Prof. JIA Xiuquanfrom the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. Richard N. Zare's group from Stanford University, have realized chemoselective electro-dechlorination of organochlorine-containing wastewater using microcloud water enriched with charged microdroplets. This study was published in the Journal of the American Chemical Society.The net charge of microdroplets plays a significant role in influencing reaction thermodynamics, facilitating electron transfer between charged droplets and thereby making the redox reactions thermodynamically feasible.In this study, the researchers reported a controllable electrochemistry process enabled within microclouds by fast phase switching of water between the microdroplet, vapor, and bulk phase. Through atomization, charge separation occurred between droplets of varying sizes, leading to self-charging and discharging cycles that generated alternating voltage in the microcloud water. This process involves electron transfer, enriching hydrogen radicals at the bulk phase surface and hydroxyl radicals within the microdroplets.The researcher demonstrated that the fast phase switching of water from bulk phase to the microdroplets enabled initial reductive dechlorination of dichloroethane in the bulk phase, followed by accelerated dehydrogenation of the dechlorination intermediate in the microdroplets. The researchers achieved a high selectivity of approximately 80% for vinyl chloride formation. The rapid phase-switching of water minimizes mass transfer limitations, overcoming the chemoselectivity challenges typical of bulk-phase electrochemical methods.“Our study indicated that beyond water treatment, cloud electrochemistry is potential for broader applications, including chemoselective electrosynthesis and air purification,” said Prof. WANG.

Autler-Townes splitting (ATS) is an important phenomenon arising from coherent interaction between a light field and a three-level system, which has been developed as a powerful tool for quantum control and quantum information processing. Traditionally, ATS is broadly studied in atoms and molecules, but the relatively weak transition dipoles of atoms and molecules lead to a small magnitude of energy splitting.Lately, quantum-confined semiconductor materials, such as quantum wells (QWs) and dots (QDs), have been studied due to their significantly stronger light-matter interaction. However, these solid-state systems tend to have broad lineshapes resulting from electron-phonon coupling and energetic disorder. Therefore, cryogenic temperatures are often required to suppress the linewidth broadening for the study of ATS.Strong Autler-Townes splitting with anomalous spectral lineshapes is observed in colloidal nanoplatelets driven by near-infrared femtosecond laser pulses (Image by LI Yuxuan)Writing in Science Advances, Prof. WU Kaifeng and his coworkers from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) observed ATS in colloidal semiconductor nanoplatelets driven by near-infrared pulses under ambient conditions. These nanoplatelets are colloidal analogues of QWs, for which the strong, atomically-precise quantum confinement in the thickness dimension results in interband and intersubband transitions in the visible and NIR regions, respectively. The mutually orthogonal dipoles of these two transitions allowed the researchers to use linearly-polarized, NIR pulses to drive the intersubband transition and to use cross-polarized, visible pulses to observe the splitting of the interband transition. Therefore, the ATS phenomenon exhibited a strong linear dichroism. The determined Autler-Townes splitting energy as large as 26 meV was among the strongest reported for various types of atomic, molecular and solid-state systems.Moreover, the researchers observed anomalous spectral lineshapes when the nanoplatelets were driven from tilted incident angles. This anomaly arose from a competition between interband and intersubband drivings, which were unprecedented in prior optical Stark effect studies but were nevertheless quantitatively captured by the developed dressed-state model simulation using a 9×9 Hamiltonian."This study not only uncovers the new physics associated with coherent light-matter interaction for anisotropic quantum-confined colloidal nanocrystals, but also has profound implications for fields ranging from coherent quantum manipulation to high-harmonics generation and ultrafast optical switching using anisotropic colloidal nanocrystals in ambient conditions," said Prof. WU.

Photocatalytic reactions that produce solar fuels through water splitting and carbon dioxide reduction offer a promising pathway for solar fuel production. A typical photocatalytic reaction consists of a complex sequence, among which the separation of photogenerated charges is a critical and long-standing challenge. This challenge limits the catalytic activity of photocatalysts and the efficiency of solar-to-chemical energy conversion, as it involves the movement of photogenerated charges across various temporal and spatial scales.Recently, a joint research team led by Prof. JIN Shengye, Prof. TIAN Wenming, Prof. LI Rengui, and Prof. LI Can from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has visualized the ultrafast charge separation process in facet-engineered photocatalyst crystals by using a home-built pump-probe transient reflection microscope (TRM). The study was published in the Journal of the American Chemical Society.Schematic illustration of spatiotemporal mapping measurements as well as the electron and hole density distribution (Image by TIAN Wenming)The researchers employed TRM to directly observe the temporal and spatial evolution of photogenerated electrons and holes on the surface of a typical photocatalyst: facet-engineered bismuth vanadate (BiVO4).The researchers demonstrated that the anisotropic built-in field within BiVO4 crystals facilitated the separation of photogenerated electrons and holes toward different facets through a two-step process spanning various timescales. Initially, the electrons and holes underwent ultrafast separation within around 6 picoseconds, with the electrons converting into localized small polarons after migrating toward the {010} facets of the truncated BiVO4 octahedral crystals. In contrast, the photogenerated holes prolong their separation, moving in a drift-diffusion manner over approximately 2,000 picoseconds before eventually accumulating on the {120} facets.Furthermore, the researchers analyzed the charge separation dynamics and demonstrated that such ultrafast separation could offer an unexpected route to enhance charge separation efficiency in BiVO4 crystals, supporting good photocatalytic performance.This work was supported by the National Natural Science Foundation of China, the CAS Projects for Young Scientists in Basic Research, the Liaoning Revitalization Talents Program, and the Fundamental Research Funds for the Central Universities.

A research group led by Prof. ZHANG Tao, Prof. ZHENG Mingyuan, and Prof. WANG Aiqin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with SinoSci Bio-EG (Zhengzhou) New Energy Technology Co., Ltd., has launched a trial for the industrial production of ethylene glycol (EG) from biomass with a production capacity of 1,000 metric tons per year.Their technique, known as DLEG technology, used catalytic conversion of biomass to bio-EG. The developed pilot plant passed evaluation by the China Petroleum and Chemical Industry Federation on Oct. 17th.EG is a major bulk chemical with a global consumption of over 30 million tons annually. It is widely used in the synthesis of polyester fibers, bottle chips, antifreeze, paints, and pharmaceuticals. China is the world’s largest producer and consumer, with annual usage exceeding 20 million tons.Traditionally, EG is produced from petroleum or coal, which has several drawbacks, including the use of non-renewable feedstocks, high CO₂ emissions, and significant energy consumption.In 2008, prof. ZHANG’s team introduced a method for the direct catalytic conversion of cellulose into EG, offering a new pathway for bio-EG production. Over the years, the team has carried out systematic research on the DLEG process, focusing on both fundamental understanding and industrial applications.A bio-EG pilot plant at a scale of 1000-ton/a (Image by DICP)In 2019, Prof. ZHANG' team and collaborators began constructing a 1000-ton pilot plant for the DLEG process. By early 2022, they established the world’s first 1,000-ton bio-EG pilot plant in Puyang, Henan. They finished the 72-hour on-site trial of the DLEG pilot plant in Oct., 2023.The results indicated that the reaction selectivity for EG was nearly 80%, with the bio-EG product reaching 99.9% purity. The ultraviolet transmittance value of bio-EG also met national standards for PET polyester synthesis. The DLEG technology demonstrated better economic viability than existing bio-EG methods that use the bio-ethanol-ethylene route. Furthermore, the DLEG process is comparable to petroleum-based EG and superior to coal-based EG commonly used in China.The pilot plant used sugars derived from starch and corn stalks as biomass feedstock for bio-EG production, employing a highly selective catalytic reaction system and an efficient product separation process. It demonstrated the advantages of a short process, mild reaction conditions, and high atom economy, contributing to a green, low-carbon circular economy route for EG production.“The DLEG technology will support China's sustainable economic development and the realization of the nation's ‘dual carbon’ goal, which refers to peaking its carbon dioxide emissions by 2030 and achieving carbon neutrality by 2060”, said Prof. ZHENG Mingyuan.