查看更多>>摘要：This paper presents the design of a new type of intelligent and versatile all-in-one therapeutic nanoplatform for the co-delivery of chemotherapeutic drugs and photosensitizers to facilitate multimodal antitumor treatment; the system is based on hyaluronic acid (HA)-modified manganese dioxide (MnO2)-enveloped hollow porous copper sulfide (CuS) nanoparticles (CuS@MnO2/HA NPs). In this system, a CuS inner shell allows for the co-loading of doxorubicin (DOX) and indocyanine green (ICG) and induces photothermal effects, and a biodegradable MnO2 external shell affords on-demand tumor microenvironment (TME)-triggered release and catalase-and Fenton-like activities. Moreover, the HA modification endows the system with a CD44 receptor-mediated tumor-targeting property. The formulated DOX and ICG co-loaded CuS@MnO2/HA (DOX/ICG-CuS@MnO2/HA) NPs were found to exhibit excellent photothermal performance both in vitro and in vivo. In addition, DOX/ICG-CuS@MnO2/HA NPs were found to display both TME and near-infrared (NIR)-responsive controlled release properties. The NPs also have a superior reactive oxygen species (ROS) generation capacity due to the combination of enhanced ICGinduced singlet oxygen and CuS@MnO2-mediated hydroxyl radicals. The cellular uptake, fluorescence imaging property, cytotoxicity, and thermal imaging of these NPs were also evaluated. In tumor bearing mice, the DOX/ICG-CuS@MnO2/HA NPs displayed a superior antitumor efficacy (2.57-fold) as compared with free DOX. Therefore, the developed DOX/ICG-CuS@MnO2/HA NPs have a great potential for use as an all-in-one nanotherapeutic agent for the efficient and precise induction of chemo/photother mal/photodynamic/chemodynamic therapy with superior antitumor efficacy and fewer side effects. (C) 2021 Published by Elsevier Inc.
查看更多>>摘要：The development of highly-efficient photocatalyst for H-2 production integrated with microplastic degradation is significant to meet the demand for clean energy and resolve "white pollution". Herein, a series of MXene/ZnxCd1-xS photocatalysts were successfully fabricated for H-2 evolution integrated with degradation of polyethylene terephthalate (PET). The resultant photocatalysts exhibited excellent photocatalytic performance, and the best photocatalytic H-2 evolution rate can reach 14.17 mmol.g(-1).h(-1) in alkaline PET alkaline solution. What's more, the PET was also converted to the useful organic micromolecule, including glycolate, acetate, ethanol, etc. The highly-efficient photocatalytic performance of MXene/ZnxCd1-xS photocatalysts can be attributed to the enhanced separation ability of photocarriers and optimum band structure with enhanced oxidation capacity of valence band. Finally, the photocatalytic mechanism was investigated in detail. Overall, this work supplied a new useful guidance for solving the energy problem and microplastic pollution issues, simultaneously. (C) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：Herein, we report that the phosphorous-doped 1 T-MoS2 as co-catalyst decorated nitrogen-doped g-C3N4 nanosheets (P-1 T-MoS2@N-g-C3N4) are prepared by the hydrothermal and annealing process. The obtained P-1 T-MoS2@N-g-C3N4 composite presents an enhanced photocatalytic N-2 reduction rate of 689.76 lmol L-1 g(-1)h(-1) in deionized water without sacrificial agent under simulated sunlight irradiation, which is higher than that of pure g-C3N4 (265.62 lmol L-1 g(-1)h(-1)), 1 T-MoS2@g-C3N4 (415.57 lmol L-1 g(-1)h-1), 1 T-MoS2@N doped g-C3N4 (469.84 lmol L-1 g(-1)h(-1)), and P doped 1 T-MoS2@g-C3N4 (531.24 lmol L-1 g(-1)h(-1)). In addition, compared with pure g-C3N4 NSs (2.64 mmol L(-)1 g(-1)h(-1)), 1 T-MoS2@g-C3N4 (4.98 mmol L-1 g(-1)h(-1)), 1 T-MoS2@N doped g-C3N4 (6.21 mmol L-1 g(-1)h(-1)), and P doped 1 T-MoS2@g-C3N4 (9.78 mmol L-1 g(-1)h(-1)), P-1 T-MoS2@N-g-C3N4 (11.12 mmol L-1 g(-1)h(-1)) composite also shows a significant improvement for photocatalytic N-2 fixation efficiency in the sacrificial agent (methanol). The improved photocatalytic activity of P-1 T-MoS2@N-g-C3N4 composite is ascribed to the following advantages: 1) Compared to pure g-C3N4, P(-)1 T-MoS2@N-g-C3N4 composite shows higher light absorption capacity, which can improve the utilization rate of the catalyst to light; 2) The P doping intercalation strategy can promote the conversion of 1 T phase MoS2, which in turn in favor of photogenerated electron transfer and reduce the recombination rate of carriers; 3) A large number of active sites on the edge of 1 T-MoS2 and the existence of N doping in g-C3N4 contribute to photocatalytic N2 fixation. (C) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：The photocatalytic degradation of organic pollutant by carbon-based materials is still a challenge. Herein, xylose-derived carbon dots (X-CDs) and chitosan-derived CDs (C-CDs) were synthesized by heteroatomsdoping strategy. Although there is almost no difference in fluorescence emission behaviors, the two types of CDs demonstrated different advantages in photocatalysis and peroxymonosulfate (PMS) activation. Comparative research revealed that the X-CDs with doping of heteroatom S was superior in the separation of electron-hole pairs, resulting in a higher catalytic performance, while the S, N co-doped C-CDs can only exhibit high photocatalytic reactivity when they were coupled with PMS. The underlying reason is that the N-related functional groups with strong electron-donating property weakened the electron trapping capacity of S-related energy level, but surface state resulting from this doping structures were conducive to promoting photo-generated electron transfer from C-CDs to PMS and played the primary role in organic oxidation. Thanks to the doping effect, both the X-CDs and C-CDs/PMS system displayed high photocatalytic performance for methylene blue removal under sunlight irradiation, showing almost 100% degradation efficiency in a 30 min period. The present study provides a valuable insight for the synthesis of CDs-based catalysts but also establishes a very promising catalytic oxidation system. (c) 2021 Published by Elsevier Inc.
查看更多>>摘要：The introduction of oxygen-defects has been a versatile strategy to enhance photocatalysis efficiency. In this work, a 2D/3D Bi/BiO2-x/Bi2WO6 heterojunction photocatalyst with rich oxygen-defective was in sequence prepared through a facile solvothermal method, which displays favorable photocatalytic activity towards organic contaminants under visible-NIR light irradiation. The enhancement in photocatalytic performance can be attributed to the synergistic effect between oxygen-vacancy-rich heterojunction and the localized surface plasmon resonance induced by metallic Bi. The functional group interaction, surface morphology, crystal structure, element composition, and tuned bandgap were investigated by FT-IR, SEM, Raman shift, ICP-MS, and XPS technique. The spectrum response performance of the photocatalyst was verified by UV-visible DRS analysis. Results of photodegradation experiments toward organic contaminants showed that the prepared photocatalyst can degrade 90% of phenol in 20 mins under visible-NIR light irradiation, both Z-scheme heterojunction and the introduction of Bi metal contribute to the enhancement in the photocatalytic activity. The results of the DFT calculation suggest that the valence band-edge hybridization within BiO2-x and Bi2WO6 can effectively enhance the photocatalytic performance by increasing the migration efficiencies of electron-hole pairs. Moreover, a possible mechanism was proposed on the results of EIS, ESR and GC-MS tests. This work offers a novel insight for syn-thesizing efficient visible-NIR light photocatalysis by activating the semiconductors with Bi metal. (C) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：Hypothesis.: Organic co-solvents, which are universally employed in adsorption studies of hydrophobic organic chemicals (HOCs), can inhibit HOC adsorption by competing for active sites on the adsorbent. The adsorbent structure can influence co-solvent interference of HOC adsorption; however, this effect remains unclear, leading to an incomplete understanding of the adsorption mechanism. Experiments.: In this study, dioctyl phthalate (DOP) was used to investigate competitive adsorption on functionalized graphene sheet in a water-methanol co-solvent system through molecular dynamics sim-ulations and quantum chemical calculations. Findings.: The simulations showed that the functional groups in the graphene defects had a strong adsorption affinity for methanol. The adsorbed methanol occupied a large number of active sites at the graphene center, thereby weakening DOP adsorption. However, the methanol adsorbed at the graphene edges could not compete with DOP for the active sites. -COOH had the strongest binding affinity for methanol among the functional groups and thus predominantly controlled the interaction between gra- phene and methanol. This study makes an innovative contribution toward understanding the competitive adsorption of methanol and DOP on functionalized graphene sheet, especially in visualizing the compe- tition for active sites, and provides theoretical guidance for the removal of HOCs and practical application of graphene. (c) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：ABSTRAC T Carbon dots (CDs) are the unique class of luminescent nanomaterials consist of various chromophoric units heterogeneously distributed throughout the nanoparticle, resulting intriguing multistate emissive properties. Herein, we have critically investigated the specific locations of the blue and green-emitting centers inside dual emissive CDs by steady-state and time-resolved polarized emission study. It is further clarified by a temperature-dependent fluorescence study for both the emitting domains. Results suggest that the blue chromophoric units are located at the interior part of CDs, while green units are mostly at the exterior region. Furthermore, we have investigated the solvent-dependent inter-chromophoric inter-actions between the two emissive domains by the Time-Resolved Area Normalized Emission Spectroscopy (TRANES). Results suggest that at polar aprotic solvent acetone, time-dependent positive evolution of green-emitting states and negative evolution of blue emissive domains have been observed. This reversible emitting properties evolve due to the excited state energy migration from blue emissive domains to green emissive domains at polar aprotic medium, while in the case of polar protic solvent water, this phenomenon is missing. This switchable inter-chromophoric interaction are correlated fur-ther with the inter-particle interactions of CDs. (c) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：Herein, the CaTiO3/Cu/TiO2 all-solid-state Z-scheme heterojunction is successfully designed via Cu nanoparticles situating at the interface between CaTiO3 and TiO2 with a new synthesis route. Interestingly, TiO2 nanosheets are generated in-situ on the surface of CaTiO3 in the second step hydrothermal reaction. The lifetimes of photoexcited carriers, photoluminescence emission spectra and transient photocurrent response tests have confirmed that the efficient Z-scheme charge transmission path of the CaTiO3/Cu/TiO2 is beneficial to facilitate the separation of photogenerated carriers and reduce their recombination efficiency. As expected, the hydrogen generation rate of CaTiO3/Cu/TiO2 is increased to 23.550 mmol g(-1)h(-1) with the appropriate amount of copper loading, which is about 981 times and 93 times higher than that of pristine CaTiO3 (0.024 mmol g(-1)h(-1)) and CaTiO3/TiO2 (0.253 mmol g(-1)h(-1)), respectively. Furthermore, the CaTiO3/Cu/TiO2 sample shows good stability in cycle experiments. Particularly, experimental results show that the non-noble metal Cu nanoparticles can be an effective electron mediator. And these merits strongly demonstrate that the CaTiO3/Cu/TiO2 composites have potential application in photocatalytic field. This study can provide fundamental guidance for designing rationally efficient non-noble metal vector Z-scheme system photocatalysts with outstanding photocatalytic H-2 generation performance. (C) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：A reasonable introduction of MOFs-derived Ni2P with high dispersity is a valid way to reduce the recom-bination rate of photogenerated electron-holes, thus for more effective visible-light-driven water split-ting. In this study, Ni-MOF-74/Ni2P precursor was obtained by low-temperature phosphating method. A ternary heterojunction Ni-MOF-74/Ni2P/MoSx with a unique structure is obtained by a solution -based mixing method. The unique structure of Ni-MOF-74/Ni2P provides advantages for MoSx load. The UV-visible diffuse reflectance spectroscopy proves that the introduction of Ni2P improves the utiliza-tion of visible light by the composite catalyst 10%-NPMS and promotes more electrons generation, thereby improving photocatalytic hydrogen production activity. It is proved that the introduced Ni2P can accelerate the separation of photogenerated carriers by characterization (PL, EIS, LSV, etc.) analyses. The composite catalyst 10%-NPMS with the best hydrogen production activity was obtained by adjusting the ratio between Ni-MOF-74/Ni2P and MoSx. The photocatalytic hydrogen evolution of the composite catalyst 10%-NPMS (286.16 lmol) is 28.30, 2.78, 3.79 and 2.41 times that of pure Ni-MOF-74, Ni2P, MoSx and binary 10%-Ni-MOF-74/MoSx within 5 h, respectively. And the hybrid 10%-Ni-MOF-74/Ni2P/ MoSx exhibits excellent photocatalytic hydrogen evolution performance and good stability. This research will provide a new strategy for synthesizing unique ternary composite materials by using metal organic framework materials as precursors. (C) 2021 Elsevier Inc. All rights reserved.
查看更多>>摘要：The dynamics of a series of soft colloids comprised of polystyrene cores with poly(N-isopropylacrylamide) (PNIPAM) coronas was investigated by diffusing wave spectroscopy (DWS). The modulus of the coronas was varied by changing the cross-link density and we were able to interpret the results within a hard-soft mapping framework. The soft, swellable particle properties were modeled using an extended Flory-Rehner theory and a Hertzian pair potential. Following volume fraction jumps, softness effects on the concentration dependence of dynamics were determined, with a 'soft colloids make strong glass-forming liquid'-type of behavior observed close to the nominal glass transition volume fraction, phi(g). Such behavior from the current systems cannot be fully explained by the osmotic deswelling model alone. However, inspired by the soft-hard mapping from Schmiedeberg et al, [Europhys. Lett. 2011, 96 specialIntscript 36010] we estimated effective hard-sphere diameters and achieved a successful mapping of the alpha-relaxation times to a master curve below phi(g). Above phi(g), the curves no longer collapse but show strong deviations from a Vogel-Fulcher type of divergence onto soft jamming plateaux. Our results provide evi-dence that osmotic deswelling itself cannot fully explain the observed dynamics. Softness also plays an important role in the dynamics of soft, concentrated colloids. (C) 2021 Elsevier Inc. All rights reserved.
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