Photocatalytic water splitting to produce green hydrogen is one of the ideal ways to convert solar energy into chemical energy. However, it still remains challenge to develop efficient photocatalysts with a wide range of visible-light absorption for this process.
　　Schematic photocatalytic water splitting into hydrogen of Ni-TBAPy-NB（Image by LIU Lifang）
　　Recently, a research group led by Prof. ZHANG Fuxiang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences developed a novel wide visible-light-responsive Ni-MOFs photocatalyst which could boost water splitting to produce hydrogen under visible-light irradiation.
　　This study was published in Journal of the American Chemical Society on Feb. 2.
　　The researchers uniformly integrated 1,3,6,8-tetrakis(p-benzoic acid)pyrene (H4TBAPy) ligand as light-harvesting center and [Ni3O16] nickel-oxide cluster as catalytic center into the MOFs single crystal framework, then subsequently exfoliated it into 2D Ni-TBAPy-NB nanobelts.
　　Benefitted from special 2D nanobelts, the ordered coordination structure and special frameworks structure contained light-harvesting center and catalytic site of the nanobelts, leading to high charge separation efficiency and water reduction activity on nanobelts. The apparent quantum efficiency (AQE) of photocatalytic water splitting to produce hydrogen reached 8.0% (420 ± 10 nm excitation).
　　"These results provide a reference for the design and synthesis of other high-efficiency MOF-based photocatalytic materials for efficient solar-to-chemical energy conversion," said Prof. ZHANG.
　　This study was supported by the National Natural Science Foundation of China, International Partnership Program of Chinese Academy of Sciences, the National Key Research and Development Program of China. (Text by LIU Lifang)

　　The oxygen evolution reaction (OER) is significant in the development and application of clean energy. Particularly, the design of high-active and acid-stable electrocatalysts is necessary to meet large-scale requirement for water electrolysis.
　　Recently, a research group led by Prof. XIAO Jianping from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) and Prof. Ryuhei Nakamura from RIKEN synthesized Co2MnO4 spinel, which showed high stability in acid environment for electrocatalysis.
　　This study was published in Nature Catalysis on Feb. 14.
　　"Density functional theoretical calculations confirmed the high activity due to the ideal binding of key intermediates from a truncated volcano activity trend," said Prof. XIAO.
　　Moreover, the researchers established multi dissolution pathways to explain the high stability of Co2MnO4 spinel in acid environment for electrocatalysis.
　　The dissolution of either Co or O was considered. Although, it showed a thermodynamic favorable for the whole reaction of dissolution, the dissolution of lattice O was found to be the most thermodynamically unfavorable elementary step in both pathways, which is the rate-limiting step.
　　The Bader charge analysis indicated a larger electron transfer from Mn to O rather than that from Co to O, which revealed a stronger binding of Mn-O and a more stable lattice O in Co2MnO4.
　　"The truncated volcano activity trend and multi dissolution pathways provided a more accurate and effective way for the rational design of catalysts for oxygen evolution reaction," said Prof. XIAO. (Text by GUO Chenxi)

　　A research team led by Prof. ZHANG Tao and Prof. LI Ning from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has synthesized renewable nylon monomers with poplar wood.
　　This study was published in Chem Catalysis on Feb. 14.
　　The researchers explored the hydrogenolysis of poplar wood over the Pd/C catalyst in the toluene/NaCl aqueous solution biphase system.
　　They found that the total carbon yield of cyclopentanone, 3-methylcyclopentanone, 2,5-hexanedione and 2,5-dimethylfuran reached to 39.2% under the investigated conditions. These compounds could be further converted to nylon monomers such as methyl-glutaric acid, glutaric acid, dimethyl methyl adipate and dimethyl adipate.
　　"This work has great significance for the catalytic conversion of raw biomass into important chemicals," said Prof. LI.
　　The study was supported by the National Natural Science Foundation of China.
　　Synthesis of renewable nylon monomers with poplar wood (Image by DICP)

　　Selective oxidation of ammonia to nitric oxide over platinum-group metal (PGM) alloy gauzes is the crucial step for nitric acid production, a century-old, and emission intensive process.
　　Therefore, it's important to develop alternative ammonia oxidation technologies with low environmental impacts and reduced catalyst cost.
　　Recently, a research group led by Prof. WANG Xiaodong from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. LI Fanxing from North Carolina State University, proposed and demonstrated an chemical looping ammonia oxidation catalyst and process to potentially replace the costly noble metal catalysts with reduced greenhouse gas emissions.
　　This study was published in Nature Communicationson Feb. 7.
　　Schematic of the chemical looping ammonia oxidation (CLAO) process and proposed reaction mechanism. (Image by RUAN Chongyan and WANG Xijun)
　　The researchers used a PGM-free V2O5 redox catalyst to achieve ammonia oxidation process. This new approach exhibited near complete NH3 conversion and exceptional NO selectivity at 650 °C, with negligible N2O production.
　　Operando spectroscopy techniques and density functional theory calculations pointed towards a modified, temporally separated Mars-van Krevelen mechanism featuring a reversible V5+/V4+ redox cycle.
　　The V=O sites were suggested to be the catalytically active center, leading to the formation of the oxidation products. Meanwhile, both V=O and doubly coordinated oxygen participate in the hydrogen transfer process.
　　The performance originated from the low activation energies for the successive hydrogen abstraction, facile NO formation as well as the easy regeneration of V=O species.
　　"Our study provides a potentially transformational process in extending the chemical looping strategy to producing base chemicals in a sustainable and cost-effective manner," said Prof. WANG.
　　This work was supported by the National Natural Science Foundation of China and the Strategic Priority Research Program of the Chinese Academy of Sciences. (Text by RUAN Chongyan)

　　Photocatalytic overall water splitting (OWS) to produce hydrogen is one of the most promising technologies to solve energy and environmental problems and realize effective conversion and storage of solar energy.
　　However, due to the lack of inefficient cocatalysts and limited understanding of the underlying mechanism, visible-light-driven photocatalytic OWS systems show relatively low efficiency with respect to the UV-light-responsive ones.
　　Unraveling of cocatalysts photodeposited selectively on facets of BiVO4 to boost solar water splitting (Image by QI Yu)
　　Recently, a research group led by Prof. LI Can, Prof. ZHANG Fuxiang and Dr. QI Yu from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has developed a highly efficient Z-scheme OWS system. The system enables benchmarked apparent quantum efficiency (AQE) and solar-to-hydrogen (STH) energy conversion efficiency over particulate inorganic semiconductor photocatalysts driven by visible light.
　　This study was published in Nat. Commun. on Jan. 25.
　　The researchers designed and developed Ir as reduction cocatalyst and FeCoOx composite as water oxidation cocatalyst, respectively.
　　Benefitted from the selective deposition of above dual cocatalysts, photogenerated charge separation and water oxidation activity on BiVO4 were achieved. The researchers assembled an efficient visible-light-driven photocatalytic OWS system with AQE of 12.3% (420 ± 10 nm excitation) through coupling with the hydrogen evolving photocatalyst.
　　In addition, they analyzed the microstructure of FeCoOx and its mechanism of promoting charge separation and water oxidation performance.
　　"These results may encourage and inspire the design and assembly of OWS systems for more efficient solar-to-chemical energy conversion." said Prof. ZHANG.
　　This work was supported by the National Natural Science Foundation of China and National Key R&D Program of China. (Text by QI Yu)

　　Type 2 diabetes (T2DM) is a systematic multi-organ metabolic disease, which is characterized by dynamic interplay among different organs.
　　Pancreatic islet-liver axis is closely associated with normal glucose regulation and homeostasis maintenance. The dysfunction of the interplay between these organs may lead to T2DM progression.
　　Recently, a group led by Prof. QIN Jianhua from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed a multi-organoid system from human induced pluripotent stem cells (hiPSCs) to simulate human liver-islet axis in normal and T2DM.
　　This study was published in Advanced Science on Dec. 23, 2021.
　　"Stem cell-derived organoid, a new class of 3D tissues, has the key structural and functional features of in vivo counterparts," said Prof. QIN.
　　This newly developed multi-organoid system could simulate human liver-pancreatic islet axis in physiological and pathological condition, and enable 3D co-culture of hiPSC-derived liver and islet organoids for up to 30 days.
　　The researchers found that the generated liver and islet organoids exhibited favorable growth and improved tissue-specific functions in this perfused microfluidic 3D culture system.
　　"The sensitive glucose-stimulated insulin secretion was from the islet organoids and it increased glucose utilization in the liver organoids," said Prof. QIN. This reflected the cooperative interaction between the two organs in this perfused co-culture system.
　　Transcriptional analyses revealed that the activated signaling pathways were associated with glucose/CYP450 metabolism and glycolysis/gluconeogenesis in liver and islet organoids.
　　What's more, this microfluidic islet-liver organoid system exhibited mitochondrial dysfunction and decreased glucose transport capacity under hyperglycemic condition, which might be attributed to the alleviated by treatment with anti-diabetic drug.
　　Schematic of hiPSCs derived multi-organoid-on-chip system to model human liver-pancreatic islet axis in vitro (Image by TAO Tingting)
　　"This novel system can not only reflect the feedback loop within the liver-islet axis, but also exhibit relevant responses to high glucose and anti-diabetes drug, which is not easily achieved by conventional cell culture and animal models," said Prof. QIN. "It will provide a unique platform for the study of complex T2DM pathogenesis and drug development."
　　This research was supported by the National Key R&D Program of China and the Strategic Priority Research Program of CAS. (Text by TAO Tingting)