Photoelectric conversion driven by sunlight has a broad range of energy/environmental applications (e.g., in solar cells and water splitting). However, difficulties are encountered in the separation of photoexcited charges. Here, we realize a long-range (∼1.5 μm period) electric polarization via asymmetric localization of surface plasmons on a three-dimensional silver structure (3D-Ag). This visible-light-responsive effect—the photo-Dember effect, can be analogous to the thermoelectric effect, in which hot carriers are thermally generated instead of being photogenerated. The induced electric field can efficiently separate photogenerated charges, enabling sunlight-driven overall water splitting on a series of dopant-free commercial semiconductor particles (i.e., ZnO, CeO2, TiO2, and WO3) once they are combined with the 3D-Ag substrate. These photocatalytic processes can last over 30 h on 3D-Ag+ZnO, 3D-Ag+CeO2, and 3D-Ag+TiO2, thus demonstrating good catalytic stability for these systems. Using commercial WO3 powder as a reference, the amount of O2 generated with 3D-Ag+CeO2 surpasses even its recently reported counterpart in which sacrificial reagents had to be involved to run half-reactions. This plasmon-mediated charge separation strategy provides an effective way to improve the efficiency of photoelectric energy conversion, which can be useful in photovoltaics and photocatalysis.
Tumor combination therapy using nano formulations with multimodal synergistic therapeutic effects shows great potential for complete ablation of tumors. However, targeting tumor metastases with nano structures is a major obstacle for therapy. Therefore, developing a combination therapy system able to target both primary tumors and their metastases at distant sites with synergistic therapy is desirable for the complete eradication of tumors. To this end, a dual chemodrug-loaded theranostic system based on single walled carbon nanohorns (SWNHs) is developed for targeting both primary breast tumors and their lung metastases. Methods: SWNHs were first modified simultaneously with poly (maleic anhydride-alt-1-octadecene) (C18PMH) and methoxypolyethyleneglycol-b-poly-D, L-lactide (mPEG-PLA) via hydrophobic-hydrophobic interactions and π-π stacking. Then cisplatin and doxorubicin (DOX) (2.9:1 molar ratio) were sequentially loaded onto the modified nanohorns in a noninterfering way. After careful examinations of the release profiles of the loaded drugs and the photothermal performance of the dual chemodrug-loaded SWNHs, termed SWNHs/C18PMH/mPEG-PLA-DOX-Pt, the dual drug chemotherapeutic and chemo-photothermal synergetic therapeutic effects on tumor cells were evaluated. Subsequently, the in vivo behavior and tumor accumulation of the drug-loaded SWNHs were studied by photoacoustic imaging (PAI). For chemo-photothermal therapy of tumors, 4T1 tumor bearing mice were intravenously injected with SWNHs/C18PMH/mPEG-PLA-DOX-Pt at a dose of 10 mg/kg b.w. (in SWNHs) and tumors were illuminated by an 808 nm laser (1W/cm2 for 5 min) 24 h post-injection. Results: DOX and cisplatin were loaded onto the modified SWNHs with high efficiency (44 wt% and 66 wt%, respectively) and released in a pH-sensitive, tandem and sustainable manner. The SWNHs/C18PMH/mPEG-PLA-DOX-Pt had a hydrodynamic diameter of 182 ± 3.2 nm, were highly stable in physiological environment, and had both dual drug chemotherapeutic (CI = 0.439) and chemo-photothermal synergistic antitumor effects (CI = 0.396) in vitro. Moreover, the dual drug-loaded SWNHs had a long blood half-life (10.9 h) and could address both the primary breast tumors and their lung metastases after intravenous administration. Consequently, chemo-photothermal combination therapy ablated the primary tumors and simultaneously eradicated the metastatic lung nodules. Conclusion: Our study demonstrates that SWNHs/C18PMH/mPEG-PLA-DOX-Pt is highly potent for chemo-photothermal combination therapy of primary tumors and cocktail chemotherapy of their metastases at a distant site.
Biological species have developed multiple effective structures to survive the process of natural selection. On page 464, D. Zhang and co-workers review recent studies on how these bio-structures can be replicated in advanced materials. This strategy not only can create various structures that are otherwise unavailable, but also provides proofs of principles for a broad range of research fields including energy and environmental science.
Micron-sized encapsulated-type MoS2/C hybrids exhibit high specific capacity, excellent rate performance and remarkable cycling stability when used as anodes in LIBs.
In this investigation, the natural 2D photonic crystals (PhCs) within peacock feathers are applied to incorporate CdS nanocrystallites. Peacock feathers are activated by ethylenediaminetetraacetic/dimethylformamide suspension to increase the reactive sites on the keratin component, on which CdS nanoparticles (nano-CdS) are in situ formed in succession and serve as the "seeds" to direct further incorporation during the following solvothermal procedure. Thus, homogeneous nano-CdS are loaded both on the feathers' surface layer and inside the 2D PhCs. The obtained nano-CdS/peacock feathers hybrids are novel photonic crystals whose photonic stop bands are markedly different from that of the natural PhCs within original peacock feathers, as observed by the reflection spectra.
A mild and simple bio‐inspired route was successfully developed to synthesize biomorphic metal oxides with hierarchical structures assembled by nanocrystallites. The biomaterials eggshell membrane (ESM) was used as the template in the synthesis process. Based on the directing and capping functions of ESM biomacromolecules for oxide nanocrystallites, the conformation transformation of the natural ESM was achieved to construct 3D interwoven porous ceramic materials. In addition, these building units nanocrystallites exhibited diverse morphologies and had a narrow size distribution with an average crystallite size of 5.4 nm for ZnO, 9.5 nm for Co 3 O 4 , and 11 nm for PdO, respectively.