As a remarkable class of plasmonic materials, two dimensional (2D) semiconductor compounds have attracted attention owing to their controlled manipulation of plasmon resonances in the visible light spectrum, which outperforms conventional noble metals. However, tuning of plasmonic resonances for 2D semiconductors remains challenging. Herein, we design a novel method to obtain amorphous molybdenum oxide (MoO ) nanosheets, in which it combines the oxidation of MoS and subsequent supercritical CO -treatment, which is a crucial step for the achievement of amorphous structure of MoO . Upon illumination, hydrogen-doped MoO exhibits tuned surface plasmon resonances in the visible and near-IR regions. Moreover, a unique behavior of the amorphous MoO nanosheets has been found in an optical biosensing system; there is an optimum plasmon resonance after incubation with different BSA concentrations, suggesting a tunable plasmonic device in the near future.

Single‐atom catalysts (SACs) play a key role in many chemical processes owing to highly desirable atom efficiency, but the challenging synthesis of these catalysts limits their commercialization and application on a large scale. Herein, we report a facile strategy to integrate atomic Pt into richly deficient MoO3−x. The core of the experimental strategy was the fabrication and utilization of HxMoO3−x with plasmon resonance that contained intercalated H+. The obtained catalyst was found to possess remarkable electrocatalytic activity toward the hydrogen evolution reaction that was even comparable to that of commercial Pt/C, whereas the amount of Pt used was reduced to only 10 % of the amount of commercial Pt/C used. Therefore, this work not only supplies a new synthesis route to SACs but also reveals the potential relation between plasmon resonance materials and the fabrication of single‐atom catalysts.

Two‐dimensional amorphous semiconductor (2DAS) monolayers can be regarded as a new phase of 2D monolayers materials and will serve as a promising field for the various electronic and optoelectronic applications. Here, together with the first‐principles calculations within density functional theory, we experimentally demonstrate that the 2DAS MoO3‐x monolayers can enhance the electrochemical nitrogen reduction reaction (NRR). To be specific, the NH3 yield and faradaic efficiency (FE) reach 35.83 ug h−1 mg−1cat at −0.40 V and 12.01 % at −0.20 V vs. reversible hydrogen electrode (RHE), respectively, and which can be dramatically improved than that of reported defective MoO3 nanosheets. Further theoretical calculations reveal that the high electrochemical performance in NH3 yield is contributed to the strong Anderson localization and electron confinement dimensionally. And such Anderson tail states can resonate effectively with the states of intermediate HNNH, playing the critical role in the rate limiting step of NRR. Integrated experimental findings and theoretical understanding, a new concept of Anderson confinement catalysis is put forward, and could be extended to other 2DAS for potential catalytic reactions.

Graphdiyne (GDY) is a new two‐dimensional ordered carbon oxide composed of sp and sp2 hybrid carbon atoms. It holds great application potential due to the uniformly distributed pores and design flexibility. However, the present preparation technology is still limited to obtain graphdiyne oxide (GDYO) nanosheets from oxidation of exfoliated GDY, just depending on strong corrosive acid as an oxidant. Herein, this work reports a simple, efficient, liquid‐phase exfoliation strategy, in which supercritical carbon dioxide (SC CO2) was first proposed to directly exfoliate GDY and prompt their oxidation into ultrathin GDYO nanosheets. The introduced CO2 molecules can cause the increase of bond lengths and bending degree of the intermediate C bond, and it can weaken and further break acetylenic bonds, which is proved by density functional theory (DFT) calculations. Meanwhile, experimentally GDYO nanosheets also show excellent light‐to‐heat conversion performance with a photothermal conversion efficiency of 63.95%. Therefore, this work provides a new environmentally friendly way to design and develop advanced carbon‐based materials and indicates GDYO‐based materials fundamentally significant in biomedicine, environmental governance.