The NIR-IIb (1500-1700 nm) window is ideal for deep-tissue optical imaging in mammals, but lacks bright and biocompatible probes. Here, we developed biocompatible cubic-phase (α-phase) erbium-based rare-earth nanoparticles (ErNPs) exhibiting bright downconversion luminescence at ~ 1600 nm for dynamic imaging of cancer immune-therapy in mice. We used ErNPs functionalized with cross-linked hydrophilic polymer layers attached to anti-PD-L1 antibody for molecular imaging of PD-L1 in a mouse model of colon cancer and achieved tumor to normal tissue signal ratios of ~ 40. The long luminescence lifetime of ErNPs (~ 4.6 ms) enabled simultaneous imaging of ErNPs and lead sulfide quantum dots (PbS QDs) emitting in the same ~ 1600 nm window. In vivo NIR-IIb molecular imaging of PD-L1 and CD8 revealed cytotoxic T *

As the most promising anode material for sodium-ion batteries (SIBs), elemental phosphorus (P) has recently gained a lot of interest due to its extraordinary theoretical capacity of 2596 mAh/g. The main drawback of a P anode is its low conductivity and rapid structural degradation caused by the enormous volume expansion (>490%) during cycling. Here, we redesigned the anode structure by using an innovative methodology to fabricate flexible paper made of nitrogen-doped graphene and amorphous phosphorus that effectively tackles this problem. The restructured anode exhibits an ultrastable cyclic performance and excellent rate capability (809 mAh/g at 1500 mA/g). The excellent structural integrity of the novel anode was further visualized during cycling by using in situ experiments inside a high-resolution transmission electron microscope (HRTEM), and the associated sodiation/desodiation mechanism was also thoroughly investigated. Finally, density functional theory (DFT) calculations confirmed that the N-doped graphene not only contributes to an increase in capacity for sodium storage but also is beneficial in regards to improved rate performance of the anode.

Engineering of the optical, electronic, and magnetic properties of hexagonal boron nitride (h-BN) nanomaterials via oxygen doping and functionalization has been envisaged in theory. However, it is still unclear as to what extent these properties can be altered using such methodology because of the lack of significant experimental progress and systematic theoretical investigations. Therefore, here, comprehensive theoretical predictions verified by solid experimental confirmations are provided, which unambiguously answer this long-standing question. Narrowing of the optical bandgap in h-BN nanosheets (from ≈5.5 eV down to 2.1 eV) and the appearance of paramagnetism and photoluminescence (of both Stokes and anti-Stokes types) in them after oxygen doping and functionalization are discussed. These results are highly valuable for further advances in semiconducting nanoscale electronics, optoelectronics, and spintronics.

The introduction of protrusions through P-doping into graphene is an effective strategy to enhance electrochemical performances in SIBs.

Integration of two-dimensional (2D) nanomaterials and their composites into energy storage devices, especially rechargeable batteries, offers opportunities to timely tackle the challenges of ever growing clean and sustainable energy demands. Therefore, it is crucial to design hybrid 2D electrode materials for high performance rechargeable batteries and to fundamentally understand their storage mechanisms at the atomic or nanoscopic levels. This review firstly describes some of the exciting progress achieved in the economic production of graphenes, 2D transition metal dichalcogenides (TMDCs), and their composites. Then we survey the recent developments in their electrochemical energy storage pathways and present the associated three kinds of storage mechanisms. In addition, we highlight the uncovered structure-performance relationships while utilizing advanced microscopic techniques, such as in situ high resolution transmission electron microscopy (TEM) and spherical aberration-corrected scanning TEM (STEM), both leading to deep unveiling and understanding of the atomic-scale ion storage/release mechanisms and hence providing clear guidance for designing optimized 2D nanostructured electrode materials. Finally, the major challenges and opportunities that researchers have to face in this field are outlined. We hope that this review can deepen the Chemical and Material Science Communities' understanding of this field and thus effectively contribute to the smart design of future-generation 2D nanostructured electrodes and exploitation of their microscopic mechanisms toward novel high-performance rechargeable batteries.

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Hydrogen evolution reaction (HER) from water electrolysis is an attractive technique developed in recent years for cost-effective clean energy. Although considerable efforts have been paid to create efficient catalysts for HER, the development of an affordable HER catalyst with superior performance under mild conditions is still highly desired. In this work, metal-organic frameworks (MOFs)-templated strategy is proposed for in situ coupling of cobalt phosphide (CoP) polyhedrons nanoparticles and carbon nanotubes (CNTs). Due to the synergistic catalytic effect between CoP polyhedrons and CNTs, the as-prepared CoP-CNTs hybrids show excellent HER performance. The resultant CoP-CNTs demonstrate excellent HER activity in 0.5 m H SO with Tafel slope of 52 mV dec , small onset overpotential of ≈64 mV, and a low overpotential of ≈139 mV at 10 mA cm . Additionally, the catalyst also manifests superior durability in acid media. Considering the structure diversity of MOFs, the strategy presented here can be extended for synthesizing other well-defined metal phosphides-CNTs hybrids, which may be used in the fields of catalysis, energy conversion and storage.

Controversial results still exist about the activities of tetrahedral (Co2+) and octahedral (Co3+) sites in Co3O4 toward the OER. Theoretical and experimental data confirm that octahedral sites are responsible for the OER, using model catalysts.