1. Science: New interface structure promotes the commercialization process of perovskite solar cells

Yi Hou and Christoph J. Brabec of the University of Erlangen-Nuremberg (common newsletter) pointed out that the main bottleneck for the further commercialization of thin-film solar cells based on mixed organic halide lead perovskites is the interface loss in the device. And through research, a general interface structure is proposed, which consists of solution-processable, highly reliable and cost-effective hole transport materials. The use of this interface structure does not affect the efficiency of perovskite solar cells. , stability or scalability. The yttrium-doped tungsten oxide (Ta-WOx)/conjugated polymer multilayer film provides a small interfacial barrier and forms quasi-ohmic contacts with various scalable conjugated polymers. In a simple device with a conventional planar structure and a self-assembled monolayer, the Ta-WOx doped perovskite solar cell achieves a maximum efficiency of 21.2% and has a light stability of over 1000 hours. Improving the interface structure by eliminating additional ion dopants greatly improves the overall performance of the cell. These findings will provide an important reference for the study of other organic materials as hole transport materials for perovskite solar cells.

2. Science: The National Renewable Energy National Laboratory proposes a new method for producing renewable acrylonitrile.

The Greg T. Beckham (Corresponding author) team of the National Renewable Energy National Laboratory has proposed a new method for the production of renewable acrylonitrile (ACN) using 3-hydroxypropionic acid (3-HP), the 3-hydroxypropionic acid. (3-HP) can be produced by a sugar microorganism. The process yields an ACN molar yield of more than 90% from ethyl 3-hydroxypropionate (ethyl 3-HP) by dehydration with an inexpensive titanium dioxide solid acid catalyst and ammonia nitridation. Subsequently, the team further explained a large-scale integration process based on this chemical reaction, which can achieve near-quantitative ACN yield (98±2%) of ethyl acrylate. This endothermic method eliminates the risk of runaway during the reaction and achieves higher yields than standard propylene ammoxidation processes, avoiding hydrogen cyanide as a by-product while increasing process safety and reducing product handling requirements.

3. Science: Pt/CeO2 low temperature activation of carbon monoxide

Professor Wang Yong from Washington State University and Abhaya K. Datye (Common Communications) team at the University of New Mexico, USA, demonstrated how atomically dispersed ionic platinum (Pt2+) on thermally stable cerium oxide (CeO2) can be treated by steam (at 750). °C) is activated to achieve the goal of low temperature carbon monoxide (CO) oxidation activity while providing excellent hydrothermal stability. It was found that a novel active site was formed on CeO2 near Pt2+, which improved the reaction conditions. These active sites are stable below 800 °C in an oxidizing environment. After steam treatment, the Pt2+ catalyst can become active at CO oxidation at 150 °C. In the study of simulated automobile exhaust, this catalyst treatment also improved its oxidizing activity for other exhaust components such as hydrocarbons.

4. Science: Selectivity enhancement of carbon dioxide electroreduction catalysis at the edge of grain boundary

The polycrystalline material generates a strain zone by displacement at the grain boundary, and thus it is possible to generate a high energy surface for catalysis. The catalytic activity of the material is considered to be related to the grain boundary density in the crystalline material, but there is no direct evidence. Stanford University Matthew W. Kanan (corresponding author) and others studied the use of electrochemical measurements and scanning electrochemical microscopy with micron resolution, indicating that the grain boundary surface edge of the gold electrode is higher than the grain surface for CO2 reduction to CO. Catalytic activity, but no comparable activity with H2 precipitation. The results provide a new strategy for further exploration of grain boundary effects in heterogeneous catalysts.

5. Science: Quantization of Chiral Edge Conduction on Domain Walls of Magnetic Topological Insulators

Control of the domain wall (DW) configuration and motion allows for a non-volatile response of the magnetic and dielectric materials under a small external magnetic field. K. Yasuda and Y. Tokura (co-author of the University of Tokyo) used magnetic force microscopy to design and fabricate magnetic domains in quantum anomalous Hall states, and demonstrated the existence of a one-dimensional edge conduction phenomenon along a specified DW by transport measurements. . The results of the study can facilitate the implementation of low-power spintronic devices.

6. Science: Characteristics of exciton condensation in transition metal chalcogenides

The University of Illinois, Luc Venema (corresponding author) et al. used a momentum-resolved electron energy loss spectrometer (M-EELS) to study the electron collection patterns in the transition metal chalcogenide semi-metal 1T-TiSe2. It is found that the electron mode energy drops to zero at non-zero momentum after approaching the phase transition temperature, indicating that the plasma fluctuates slowly and the valence electrons crystallize into exciton. The results provide convincing evidence for exciton condensation in three-dimensional solids and demonstrate the use of M-EELS to study valence band excitation in quantum materials.

7. Science: Synthesis of ultra-small bimetallic nanoparticles on a silica support

The University of South Carolina, JR Regalbuto (corresponding author) designed a relatively simple, efficient, and universal method for the preparation of highly dispersed, well-alloyed bimetallic nanoparticles that can be used to achieve precious metals and alkali metals (Pt, Pd, Co-adsorption of any two of Co, Cu, and Ni) produces supported bimetallic nanoparticles with uniform dispersion, uniform alloying, and average particle size of 0.9-1.4 nm.

8, Nature: "Electricity" inspired hydrogel soft power supply

The combination of propulsion technology and organisms requires that the power source be biocompatible, mechanically flexible, and utilize the chemical energy inside the biological system. University of Michigan Michael Mayer (corresponding author) and others were inspired by the eDonkey to develop a soft power supply. The ion gradient changes between the gel components are achieved by repeating the arrangement of the cationic and cationic selective gel membranes to form a micro-polyacrylamide gel. The conductive pathway formed after stacking of the system can generate an open circuit voltage of 110 volts, while each gel The battery square meter reaches 27 milliwatts. This power device can be used to power next-generation portable materials such as pacemakers, sensors or prostheses.

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