Bo Tang

Abstract The discovery of stable and noble‐metal‐free catalysts toward efficient electrochemical reduction of nitrogen (N 2 ) to ammonia (NH 3 ) is highly desired and significantly critical for the earth nitrogen cycle. Here, based on the theoretical predictions, MoS 2 is first utilized to catalyze the N 2 reduction reaction (NRR) under room temperature and atmospheric pressure. Electrochemical tests reveal that such catalyst achieves a high Faradaic efficiency (1.17%) and NH 3 yield (8.08 × 10 −11 mol s −1 cm −1 ) at −0.5 V versus reversible hydrogen electrode in 0.1 m Na 2 SO 4 . Even in acidic conditions, where strong hydrogen evolution reaction occurs, MoS 2 is still active for the NRR. This work represents an important addition to the growing family of transition‐metal‐based catalysts with advanced performance in NRR.

Abstract Conversion of naturally abundant nitrogen to ammonia is a key (bio)chemical process to sustain life and represents a major challenge in chemistry and biology. Electrochemical reduction is emerging as a sustainable strategy for artificial nitrogen fixation at ambient conditions by tackling the hydrogen- and energy-intensive operations of the Haber–Bosch process. However, it is severely challenged by nitrogen activation and requires efficient catalysts for the nitrogen reduction reaction. Here we report that a boron carbide nanosheet acts as a metal-free catalyst for high-performance electrochemical nitrogen-to-ammonia fixation at ambient conditions. The catalyst can achieve a high ammonia yield of 26.57 μg h –1 mg –1 cat. and a fairly high Faradaic efficiency of 15.95% at –0.75 V versus reversible hydrogen electrode, placing it among the most active aqueous-based nitrogen reduction reaction electrocatalysts. Notably, it also shows high electrochemical stability and excellent selectivity. The catalytic mechanism is assessed using density functional theory calculations.

), ATP, HCHO, CO and so on, are a highly important category of molecules in living cells. The dynamic fluctuations of these molecules in subcellular microenvironments determine cellular homeostasis, signal conduction, immunity and metabolism. However, their abnormal expressions can cause disorders which are associated with diverse major diseases. Monitoring bioactive molecules in subcellular structures is therefore critical for bioanalysis and related drug discovery. With the emergence of organelle-targeted fluorescent probes, significant progress has been made in subcellular imaging. Among the developed subcellular localization fluorescent tools, ROS, RNS and RSS (RONSS) probes are highly attractive, owing to their potential for revealing the physiological and pathological functions of these highly reactive, interactive and interconvertible molecules during diverse biological events, which are rather significant for advancing our understanding of different life phenomena and exploring new technologies for life regulation. This review mainly illustrates the design principles, detection mechanisms, current challenges, and potential future directions of organelle-targeted fluorescent probes toward RONSS.

Abstract The industrial artificial fixation of atmospheric N 2 to NH 3 is carried out using the Haber–Bosch process that is not only energy‐intensive but emits large amounts of greenhouse gas. Electrochemical reduction offers an environmentally benign and sustainable alternative for NH 3 synthesis. Although Mo‐dependent nitrogenases and molecular complexes effectively catalyze the N 2 fixation at ambient conditions, the development of a Mo‐based nanocatalyst for highly performance electrochemical N 2 fixation still remains a key challenge. Here, greatly boosted electrocatalytic N 2 reduction to NH 3 with excellent selectivity by defect‐rich MoS 2 nanoflowers is reported. In 0.1 m Na 2 SO 4 , this catalyst attains a high Faradic efficiency of 8.34% and a high NH 3 yield of 29.28 µg h −1 mg −1 cat. at − 0.40 V versus reversible hydrogen electrode, much larger than those of defect‐free counterpart (2.18% and 13.41 µg h −1 mg −1 cat. ), with strong electrochemical stability. Density functional theory calculations show that the potential determining step has a lower energy barrier (0.60 eV) for defect‐rich catalyst than that of defect‐free one (0.68 eV).

Abstract Photodynamic therapy (PDT) is ineffective against deeply seated metastatic tumors due to poor penetration of the excitation light. Herein, we developed a biomimetic nanoreactor (bio-NR) to achieve synergistic chemiexcited photodynamic-starvation therapy against tumor metastasis. Photosensitizers on the hollow mesoporous silica nanoparticles (HMSNs) are excited by chemical energy in situ of the deep metastatic tumor to generate singlet oxygen ( 1 O 2 ) for PDT, and glucose oxidase (GOx) catalyzes glucose into hydrogen peroxide (H 2 O 2 ). Remarkably, this process not only blocks the nutrient supply for starvation therapy but also provides H 2 O 2 to synergistically enhance PDT. Cancer cell membrane coating endows the nanoparticle with biological properties of homologous adhesion and immune escape. Thus, bio-NRs can effectively convert the glucose into 1 O 2 in metastatic tumors. The excellent therapeutic effects of bio-NRs in vitro and in vivo indicate their great potential for cancer metastasis therapy.