Heliang Yao

A Facile One‐Pot Synthesis of a Two‐Dimensional MoS2/Bi2S3 Composite Theranostic Nanosystem for Multi‐Modality Tumor Imaging and Therapy

2D PEG-ylated MoS2/Bi2 S3 composite nanosheets are successfully constructed by introducing bismuth ions to react with the two extra S atoms in a (NH4)2 MoS4 molecule precursor for solvothermal synthesis of MoS2. The MBP nanosheets can serve as a promising platform for computed tomography and photoacoustic-imaging-guided tumor diagnosis, as well as combined tumor photothermal therapy and sensitized radiotherapy.

Pd-catalyzed instant hydrogenation of TiO2 with enhanced photocatalytic performance

Hydrogenated TiO2 with remarkably elevated photocatalytic activity has triggered great interest, which, unfortunately, has been commonly obtained so far under severe conditions such as extraordinarily high pressure (20.0 bar) and/or high temperature (up to 700 °C) over a long period of treatment (up to several days). Here, through doping with a slight amount of Pd, hydrogenated TiO2 is obtained at room temperature under non-pressurised H2 or H2/O2 gas flow within several minutes. This extremely facile Pd-catalyzed hydrogenation strategy is based on the discovered fact that H2 could spontaneously dissociate on the Pd surface to generate highly active atomic hydrogen species [H], which would diffuse into and interact with the TiO2 lattice to generate durable point defects (Ti3+, oxygen vacancies) and even surface disorder, resulting in the largely enhanced solar energy utilization of TiO2. Additionally, the proposed Pd-catalyzed hydrogenation strategy turns out to be applicable to reduce other transition metal oxides, providing a general methodology for oxide hydrogenation under ordinary conditions.

Template-free formation of various V2O5 hierarchical structures as cathode materials for lithium-ion batteries

Various V2O5 hierarchical structures were successfully synthesized via a template-free method by annealing diverse morphological VO2 sub-microspheres which can be facilely tailored by adjusting the solvothermal reaction duration. The VO2 sub-microspheres undergo a solid → yolk–shell → hollow → yolk–shell structure process with increasing time, which is believed to result from an unusual Ostwald-ripening process. After the annealing process, multi-structural VO2 sub-microspheres changed into hierarchical structures including fist-type structures consisting of nanorods, yolk–shell and hollow sub-microspheres composed of nanorods and a yolk–shell construction made up of nanoplates. As the cathode materials for lithium-ion batteries, among them, yolk–shell sub-microspheres comprised of nanoplates exhibited high reversible capacity, excellent cycling stability at high currents and good rate capacities. Without doping and compositing, the electrode delivered reversible capacities of 119.2 and 87.3 mA h g−1 at high current densities of 2400 and 3600 mA g−1, respectively, as well as a capacity retention of 78.31% after 80 cycles at 1200 mA g−1. The excellent electrochemical performance could be attributed to the purity of the phase and synergistic effect between the yolk–shell structure and hierarchical structure of the sub-microspheres, which make the yolk–shell V2O5 hierarchical structure a promising candidate for the cathode material for lithium-ion batteries.

One-step replication and enhanced catalytic activity for cathodic oxygen reduction of the mesostructured Co3O4/carbon composites

Mesostructured Co3O4/C composites of high surface area have been synthesized via a one-step replica route by co-nanocasting cobalt and carbon precursors into mesoporous silica, in which the Co3O4 nanoparticles are homogeneously dispersed in the mesoporous structure of carbon substrates. The mesostructured composites showed relatively high catalytic activities for oxygen reduction reaction (ORR), and that with a Co loading content of 4.3 at% exhibited the best electrochemical performance for ORR. The relatively high catalytic activity is attributed to the effects of the redox couples (Co(3+)/Co(2+)) together with the contribution from the conductive mesoporous carbon substrate.

Core-shell hierarchical mesostructured silica nanoparticles for gene/chemo-synergetic stepwise therapy of multidrug-resistant cancer

The design and synthesis of hierarchically nanoporous structures for the co-encapsulation and sequential releases of different cargos are still great challenges in biomedical applications. In this work, we report on the elaborate design and controlled synthesis of a unique core-shell hierarchical mesoporous silica/organosilica nanosystem, in which there are large and small mesopores separately present in the shell and core, facilitating the independent encapsulations of large (siRNA) and small (doxorubicin) molecules, respectively. Importantly, the framework of the organosilica shell is molecularly hybridized with disulfide bonds, which enables the unique responsiveness to the reductive tumor microenvironment for the controlled releasing of loaded gene molecules, followed by the subsequent doxorubicin release. The first released large siRNA molecules from the organosilica shell down-regulated the expression of P-gp in the cell membrane and reversed the MDR of cancer cells, thus enhancing the antitumor effect of subsequently released small DOX molecules from the silica core, and in such a synergetic way the MDR tumor growth can be efficiently inhibited. This work shows the significant advantages compared to the traditional small-mesoporous or large-mesoporous nanosystems for drug co-delivery.

On the Mesoporogen‐Free Synthesis of Single‐Crystalline Hierarchically Structured ZSM‐5 Zeolites in a Quasi‐Solid‐State System

Hierarchically structured zeolites (HSZs) have gained much academic and industrial interest owing to their multiscale pore structures and consequent excellent performances in varied chemical processes. Although a number of synthetic strategies have been developed in recent years, the scalable production of HSZs single crystals with penetrating and three-dimensionally (3-D) interconnected mesopore systems but without using a mesoscale template is still a great challenge. Herein, based on a steam-assisted crystallization (SAC) method, we report a facile and scalable strategy for the synthesis of single-crystalline ZSM-5 HSZs by using only a small amount of micropore-structure-directing agents (i.e., tetrapropylammonium hydroxide). The synthesized materials exhibited high crystallinity, a large specific surface area of 468 m(2)  g(-1) , and a pore volume of 0.43 cm(3)  g(-1) without sacrificing the microporosity (≈0.11 cm(3)  g(-1) ) in a product batch up to 11.7 g. Further, a kinetically controlled nucleation-growth mechanism is proposed for the successful synthesis of single-crystalline ZSM-5 HSZs with this novel process. As expected, compared with the conventional microporous ZSM-5 and amorphous mesoporous Al-MCM-41 counterparts, the synthesized HSZs exhibited significantly enhanced activity and stability and prolonged lifetime in model reactions, especially when bulky molecules were involved.

2D‐Black‐Phosphorus‐Reinforced 3D‐Printed Scaffolds:A Stepwise Countermeasure for Osteosarcoma

With the ever-deeper understanding of nano-bio interactions and the development of fabrication methodologies of nanomaterials, various therapeutic platforms based on nanomaterials have been developed for next-generation oncological applications, such as osteosarcoma therapy. In this work, a black phosphorus (BP) reinforced 3D-printed scaffold is designed and prepared to provide a feasible countermeasure for the efficient localized treatment of osteosarcoma. The in situ phosphorus-driven, calcium-extracted biomineralization of the intra-scaffold BP nanosheets enables both photothermal ablation of osteosarcoma and the subsequent material-guided bone regeneration in physiological microenvironment, and in the meantime endows the scaffolds with unique physicochemical properties favoring the whole stepwise therapeutic process. Additionally, a corrugated structure analogous to Haversian canals is found on newborn cranial bone tissue of Sprague-Dawley rats, which may provide much inspiration for the future research of bone-tissue engineering.

High Performance and Enhanced Durability of Thermochromic Films Using VO2@ZnO Core–Shell Nanoparticles

For VO2-based thermochromic smart windows, high luminous transmittance (Tlum) and solar regulation efficiency (ΔTsol) are usually pursued as the most critical issues, which have been discussed in numerous researches. However, environmental durability, which has rarely been considered, is also so vital for practical application because it determines lifetime and cycle times of smart windows. In this paper, we report novel VO2@ZnO core-shell nanoparticles with ultrahigh durability as well as improved thermochromic performance. The VO2@ZnO nanoparticles-based thermochromic film exhibits a robust durability that the ΔTsol keeps 77% (from 19.1% to 14.7%) after 103 hours in a hyperthermal and humid environment, while a relevant property of uncoated VO2 nanoparticles-based film badly deteriorates after 30 h. Meanwhile, compared with the uncoated VO2-based film, the VO2@ZnO-based film demonstrates an 11.0% increase (from 17.2% to 19.1%) in ΔTsol and a 31.1% increase (from 38.9% to 51.0%) in Tlum. Such integrated thermochromic performance expresses good potential for practical application of VO2-based smart windows.

Selective and Tunable Near‐Infrared and Visible Light Transmittance of MoO3−x Nanocomposites with Different Crystallinity

In this Communication, we report MoO3-x nanocomposites in which the near-infrared and visible light transmittance can be selectively modulated through the crystallinity. The MoO3-x nanocomposites were fabricated by a hydrothermal method, and their optical properties were characterized by UV-Vis spectrometer. The obtained results proved the possibility to tune the nanocomposites optical properties in the UV/Visible spectral region: crystalline MoO3 mainly regulates the near-infrared range (800-2600 nm), and amorphous MoO3-x mainly changes the visible range from 350 nm to 800 nm and MoO3-x , with semi-crystalline structures mainly modulating around 800-1000 nm. These kinds of optical modulations could be attributed to small polar absorption, free electron absorption and plasmon absorption according to different crystallinity. Our work may create new possibilities for future applications such as photochromism, photocatalysis, and electrochromism.

One-pot synthesis of hierarchically structured ZSM-5 zeolites using single micropore-template

Abstract An easy one-step hydrothermal process has been developed for the first time for the synthesis of hierarchically structured zeolites (HSZs) using a single micropore template of tetrapropylammonium hydroxide. Compared with conventional constructive dual-templating synthesis and destructive post-demetallation methods, this two-in-one process reduces the mass of porogens required and consequent air pollution by combustion of the template, and simplifies the synthesis. The resultant HSZs were characterized by X-ray diffraction, N2 adsorption, scanning electron microscopy, transmission electron microscopy, X-ray fluorescence, 27Al nuclear magnetic resonance, and NH3 temperature programmed desorption. The resultant HSZs with uniform shuttle-type morphology showed high hydrothermal stability and excellent catalytic activity with prolonged life-time in the model reaction of 1,3,5-triisopropylbenzene cracking. A “nucleation/growth-demetallation/recrystallization” mechanism was proposed, which is featured with the integration of zeolite crystallization/growth and basic etching into one hydrothermal process for HSZs production.