A Scalable Methylamine Gas Healing Strategy for High‐Efficiency Inorganic Perovskite Solar Cells

An easy and scalable methylamine (MA) gas healing method was realized for inorganic cesium‐based perovskite (CsPbX₃) layers by incorporating a certain amount of MAX (X=I or Br) initiators into the raw film. It was found that the excess MAX accelerated the absorption of the MA gas into the CsPbX₃ film and quickly turned it into a liquid intermediate phase. Through the healing process, a highly uniform and highly crystalline CsPbX₃ film with enhanced photovoltaic performance was obtained. Moreover, the chemical interactions between a series of halides and MA gas molecules were studied, and the results could offer guidance in further optimizations of the healing strategy.     

Directed Evolution of a Bacterial Laccase (CueO) for Enzymatic Biofuel Cells

Escherichia coli's copper efflux oxidase (CueO) has rarely been employed in the cathodic compartment of enzymatic biofuel cells (EBFCs) due to its low redox potential (0.36 V vs. Ag/AgCl, pH 5.5) towards O₂ reduction. Herein, directed evolution of CueO towards a more positive onset potential was performed in an electrochemical screening system. An improved CueO variant (D439T/L502K) was obtained with a significantly increased onset potential (0.54 V), comparable to that of high‐redox‐potential fungal laccases. Upon coupling with an anodic compartment, the EBFC exhibited an open‐circuit voltage (V_oc) of 0.56 V. Directed enzyme evolution by tailoring enzymes to application conditions in EBFCs has been validated and might, in combination with molecular understanding, enable future breakthroughs in EBFC performance     

Platinum/Nickel Bicarbonate Heterostructures towards Accelerated Hydrogen Evolution under Alkaline Conditions

Heterostructured nanomaterials, generally have physicochemical properties that differ from those of the individual components, and thus have potential in a wide range of applications. New platinum (Pt)/nickel bicarbonate (Ni(HCO₃)₂) heterostructures are designed for an efficient alkaline hydrogen evolution reaction (HER). Notably, the specific and mass activity of Pt in Pt/Ni(HCO₃)₂ are substantially improved compared to the bare Pt nanoparticles (NPs). The Ni(HCO₃)₂ provides abundant water adsorption/dissociation sites and modulate the electronic structure of Pt, which determine the elementary reaction kinetics of alkaline HER. The Ni(HCO₃)₂ nanoplates offer a platform for the uniform dispersion of Pt NPs, ensuring the maximum exposure of active sites. The results demonstrate that, Ni(HCO₃)₂ is an effective catalyst promoter for alkaline HER.     

Cleavage of C(aryl)−CH3 Bonds in the Absence of Directing Groups under Transition Metal Free Conditions

Organic chemists now can construct carbon–carbon σ‐bonds selectively and sequentially, whereas methods for the selective cleavage of carbon–carbon σ‐bonds, especially for unreactive hydrocarbons, remain limited. Activation by ring strain, directing groups, or in the presence of a carbonyl or a cyano group is usually required. In this work, by using a sequential strategy site‐selective cleavage and borylation of C(aryl)?CH₃ bonds has been developed under directing group free and transition metal free conditions. Methyl groups of various arenes are selectively cleaved and replaced by boryl groups. Mechanistic analysis suggests that it proceeds by a sequential intermolecular oxidation and coupling of a transient aryl radical, generated by radical decarboxylation, involving a pyridine‐stabilized persistent boryl radical.     

Organic Semiconducting Pro‐nanostimulants for Near‐Infrared Photoactivatable Cancer Immunotherapy

In this study, an organic semiconducting pro‐nanostimulant (OSPS) with a near‐infrared (NIR) photoactivatable immunotherapeutic action for synergetic cancer therapy is presented. OSPS comprises a semiconducting polymer nanoparticle (SPN) core and an immunostimulant conjugated through a singlet oxygen (¹O₂) cleavable linkers. Upon NIR laser irradiation, OSPS generates both heat and ¹O₂ to exert combinational phototherapy not only to ablate tumors but also to produce tumor‐associated antigens. More importantly, NIR irradiation triggers the cleavage of ¹O₂‐cleavable linkers, triggering the remote release of the immunostimulants from OSPS to modulate the immunosuppressive tumor microenvironment. Thus, the released tumor‐associated antigens in conjunction with activated immunostimulants induce a synergistic antitumor immune response after OSPS‐mediated phototherapy, resulting in the inhibited growth of both primary/distant tumors and lung metastasis in a mouse xenograft model, which is not observed for sole phototherapy.     

High Efficiency Electrochemical Nitrogen Fixation Achieved with a Lower Pressure Reaction System by Changing the Chemical Equilibrium

We demonstrate a simple and effective chemical equilibrium regulation strategy to improve the efficiency of electrochemical ammonia synthesis by constructing electrochemical reaction system that works at significantly lower pressure than the Haber–Bosch process. Transferring the nitrogen reduction reaction from ambient conditions to a lightly pressurized environment not only accelerates the activation of the N≡N triple bond but also inhibits the competing reaction of hydrogen evolution while promoting the dissolution and diffusion of nitrogen. The verification experiment of using well‐designed Fe₃Mo₃C/C composite nanosheets as the nitrogen reduction catalyst shows that the lower pressure reaction system can improve the Faradaic current efficiency by one order of magnitude. Moreover, the comparatively low‐pressure reaction system can greatly reduce the cell voltage of the ammonia synthesis reaction (up to 33 %) even at the relatively low pressure of 0.7 MPa, which is of significance for decreasing the energy consumption of electrochemical ammonia synthesis under mild conditions.     

Elucidating Ultrafast Molecular Permeation through Well‐Defined 2D Nanochannels of Lamellar Membranes

Lamellar membranes with well‐defined 2D nanochannels show fast, selective permeation, but the underlying molecular transport mechanism is unexplored. Now, regular robust MXene Ti₃C₂T_x lamellar membranes are prepared, and the size and wettability of nanochannels are manipulated by chemically grafted hydrophilic (?NH₂) or hydrophobic (?C₆H₅, ?C₁₂H₂₅) groups. These nanochannels have a sharp difference in mass transfer behavior. Hydrophilic nanochannels, in which polar molecules form orderly aligned aggregates along channel walls, impart ultrahigh permeance (>3000 L m^?2 h^?1 bar^?1), which is more than three times higher than that in hydrophobic nanochannels with disordered molecular configuration. In contrast, nonpolar molecules with disordered configuration in both hydrophilic and hydrophobic nanochannels have comparable permeance. Two phenomenological transport models correlate the permeance with the mass transport mechanism of molecules that display ordered and disordered configuration.     

基于室温脉冲量子级联激光器的NO气体检测中的光谱处理方法研究

报导了采用基于室温脉冲量子级联激光器的脉内光谱检测技术,利用中心波长为1904 cm^-1的量子级联激光器,在实验室对NO气体样品进行检测的研究结果. 针对单线直接吸收光谱反演算法进行了研究,介绍了基线拟合的最小二乘算法以获取其吸光度,根据HITRAN数据库中相应吸收谱线的吸收线强,采用扫描积分实现了气体浓度的反演,避免了标气标定造成的误差及污染;通过拟合残差分析得到了系统的检测限,达到34×10^-6 m. 关键词： 量子级联激光器 中红外 多项式拟合 扫描积分     

A Smart Dental Floss for Biosensing of Glucose

The development of a simple directly wearable approach for the rapid, specific and sensitive determination of biomarkers is of great importance to a variety of biomedical applications. Dental floss can provide a unique device platform for sensing of oral biomarkers. We show here for the first time the development of a smart dental floss for biosensing of glucose. The sensor was made by painting carbon graphite ink and Ag/AgCl ink on dental floss. Via the immobilization of glucose oxidase, we show the detection of glucose with a detection range of 0.048 mM to 19.5 mM and a response time of about 2 min. It is expected that our results could provide new exciting opportunities for the development of various flexible smart sensing devices in oral health applications.