Dynamically Unveiling Metal-Nitrogen Coordination during Thermal Activation to Design High-Efficient Atomically Dispersed CoN Active Sites.

We elucidate the structural evolution of CoN sites during thermal activation by developing a zeolitic imidazolate framework (ZIF)-8-derived carbon host as an ideal model for Co ion adsorption. Subsequent in situ X-ray absorption spectroscopy analysis can dynamically track the conversion from inactive Co-OH and Co-O species into active CoN sites. The critical transition occurs at 700 °C and becomes optimal at 900 °C, generating the highest intrinsic activity and four-electron selectivity for the oxygen reduction reaction (ORR).

Eyeball-Like Yolk-Shell Bimetallic Nanoparticles for Synergistic Photodynamic-Photothermal Therapy.

Noble metal-based nanomaterials offer great potential as cargoes for multifunctional cancer treatment. In this research, Au eyeball-like nanoparticles (NPs) with open-mouthed Pd shells were synthesized and their surface was functionalized with cell-targeting ligand folic acid (FA) and photodynamic agent Chlorin e6 (Ce6). Due to the broad near-infrared (NIR) absorption band of eyeball-like bimetallic Au and Pd, the photothermal therapy effects of this nanomaterial were studied in MCF-7 cancer cells.

Chemical Vapor Deposition for Atomically Dispersed and Nitrogen Coordinated Single Metal Site Catalysts.

Atomically dispersed and nitrogen coordinated single metal sites (M-N-C, M=Fe, Co, Ni, Mn) are the popular platinum group-metal (PGM)-free catalysts for many electrochemical reactions. Traditional wet-chemistry catalyst synthesis often requires complex procedures with unsatisfied reproducibility and scalability. Here, we report a facile chemical vapor deposition (CVD) strategy to synthesize the promising M-N-C catalysts.

Au@Pd Nanopopcorn and Aptamer Nanoflower Assisted Lateral Flow Strip for Thermal Detection of Exosomes.

Conventional lateral flow biosensing technologies face the dual formidable challenges of poor sensitivity and cumbersome quantitative devices. Here, we developed a Au@Pd nanopopcorn and aptamer nanoflower assisted lateral flow strip (ANAN-LFS) with a thermal signal output to improve detection sensitivity. Moreover, a smartphone-based thermal reader was designed and meticulously optimized to hand-held style, realizing the essential portability of this quantitative device.

Bioinspired Peptoid Nanotubes for Targeted Tumor Cell Imaging and Chemo-Photodynamic Therapy.

Substantial progress has been made in applying nanotubes in biomedical applications such as bioimaging and drug delivery due to their unique architecture, characterized by very large internal surface areas and high aspect ratios. However, the biomedical applications of organic nanotubes, especially for those assembled from sequence-defined molecules, are very uncommon. In this paper, the synthesis of two new peptoid nanotubes (PepTs1 and PepTs2) is reported by using sequence-defined and ligand-tagged peptoids as building blocks.

Rapid and selective detection of Fe (III) by using a smartphone-based device as a portable detector and hydroxyl functionalized metal-organic frameworks as the fluorescence probe.

Here, a label-free fluorescent sensor was developed for detection Fe (III) by utilizing the quenching effect of Fe (III) on the fluorescence of the hydroxyl functionalized metal-organic framework MIL-53(Fe)-(OH), which was synthesized by using a one-step solvothermal method. The specific binding interaction between Fe (III) and hydroxyl facilitated the absorption of free Fe (III) to MIL-53(Fe)-(OH) which leads to rapid fluorescent intensity quenching effect. The potential quenching mechanism was proved to be the photo-induced electron transfer (PET) from electron-rich ligands of MIL-53(Fe)-(OH) to the half-filled 3d orbitals of free Fe (III) in the sample solution.

Robust noble metal-based electrocatalysts for oxygen evolution reaction.

The oxygen evolution reaction (OER) is a kinetically sluggish anodic reaction and requires a large overpotential to deliver appreciable current. Despite the fact that non-precious metal-based alkaline water electrocatalysts are receiving increased attention, noble metal-based electrocatalysts (NMEs) applied in proton exchange membrane water electrolyzers still have advantageous features of larger current and power densities with lower stack cost. Engineering NMEs for OER catalysis with high efficiency, durability and utilization rate is of vital importance in promoting the development of cost-effective renewable energy production and conversion devices.

Assembling Carbon Pores into Carbon Sheets: Rational Design of Three-Dimensional Carbon Networks for a Lithium-Sulfur Battery.

The conversion reaction-based lithium-sulfur battery features an attractive energy density of 2600 W h/kg. Nevertheless, the unsatisfied performance in terms of poor discharge capacity and cycling stability still hinders its practical applications. Recently, porous carbon materials have been widely reported as promising sulfur reservoirs to promote the sluggish reaction kinetics of sulfur conversion, tolerate volume expansion of sulfur, and suppress polysulfide shuttling.

Mitochondrial-targeted multifunctional mesoporous Au@Pt nanoparticles for dual-mode photodynamic and photothermal therapy of cancers.

In the conventional non-invasive cancer treatments, such as photodynamic therapy (PDT) and photothermal therapy (PTT), light irradiation is precisely focused on tumors to induce apoptosis via the generation of reactive oxygen species (ROS) or localized heating. However, overconsumption of oxygen and restricted diffusion distance of ROS limit the therapeutic effects on hypoxic tumors. Herein, we developed a platform for the rapid uptake of multifunctionalized Au@Pt nanoparticles (NPs) by mitochondria in cancer cells.

Self-Assembled Fe-N-Doped Carbon Nanotube Aerogels with Single-Atom Catalyst Feature as High-Efficiency Oxygen Reduction Electrocatalysts.

Self-assembled M-N-doped carbon nanotube aerogels with single-atom catalyst feature are for the first time reported through one-step hydrothermal route and subsequent facile annealing treatment. By taking advantage of the porous nanostructures, 1D nanotubes as well as single-atom catalyst feature, the resultant Fe-N-doped carbon nanotube aerogels exhibit excellent oxygen reduction reaction electrocatalytic performance even better than commercial Pt/C in alkaline solution.

Highly branched PtCu bimetallic alloy nanodendrites with superior electrocatalytic activities for oxygen reduction reactions.

Morphology control is a promising strategy to improve the catalytic performance of Pt-based catalysts. In this work, we reported a facile synthesis of PtCu bimetallic alloy nanodendrites using Brij 58 as a template. The highly branched structures and porous features offer relatively large surface areas, which is beneficial to the enhancement of the catalytic activity for oxygen reduction reactions in fuel cells.

One-Pot Fabrication of Mesoporous Core-Shell Au@PtNi Ternary Metallic Nanoparticles and Their Enhanced Efficiency for Oxygen Reduction Reaction.

Currently, Pt-based nanomaterials with tailorable shapes, structures, and morphologies are the most popular electrocatalysts for oxygen reduction reaction, which is a significant cathode reaction in fuel cells for renewable energy applications. We have successfully synthesized mesoporous core-shell Au@PtNi ternary metallic nanoparticles through a one-pot reduction method for cathodic materials used as oxygen reduction reaction catalysts. The as-synthesized nanoparticles exhibited superior catalytic activities and long-term stabilities compared with mesoporous core-shell Au@Pt nanoparticles and commercial Pt/C.