Search

NIR-activated therapies based on light-responsive drug delivery systems are emerging as a remote-controlled method for cancer precise therapy. In this work, fluorescent dye indocyanine green (ICG)-conjugated and bioactive compound gambogic acid (GA)-loaded polymeric micelles (GA@PEG-TK-ICG PMs) were smoothly fabricated via the self-assembly of the reactive oxygen species (ROS)-responsive thioketal (TK)-linked amphiphilic polymer poly(ethyleneglycol)-thioketal-(indocyanine green) (PEG-TK-ICG). The resultant micelles demonstrated increased resistance to photobleaching, enhanced photothermal conversion efficiency, NIR-controlled drug release behavior, preferable biocompatibility, and excellent tumor accumulation performance. Moreover, upon an 808 nm laser irradiation, the micellar photoactive chromophore ICG converted the absorbed optical energy to both hyperthermia for photothermal therapy (PTT) and ROS as the feedback trigger to the micelles for the tumor-specific release of GA, which could serve as not only a chemotherapeutic drug to directly kill tumor cells but also a heat shock protein 90 (HSP90) inhibitor to realize the photothermal sensitization. As a result, an extremely high tumor inhibition rate (97.9%) of mouse 4 T1 breast cancer models was achieved with negligible side effects after the chemo-photothermal synergistic therapy. This NIR-activated nanosystem with photothermal self-sensitization function may provide a feasible option for the effective treatment of aggressive breast cancers.

A multi-functional NiMo-ceria-zirconia composite was developed as an anode for a solid oxide fuel cell (SOFC) running on isooctane, a commonly used gasoline surrogate. The anode layer was fabricated on an electrolyte-supported single cell using yttria-stabilized zirconia (YSZ) as the electrolyte and La0.6Sr0.4Co0.2Fe0.8O3-δ as the cathode. Our results indicate that the single NiMo-ceria-zirconia layer possesses a dual-functionality: firstly to internally convert complex hydrocarbons into synthesis gas with a high resistance to coking and secondly to electrochemically oxidize the synthesis gas mixture for electric power generation. Compared with the conventional Ni-YSZ anode single cell, the application of the ceria-zirconia in the anode significantly suppresses carbon deposition and improves the performance stability of the single cell. Furthermore, the addition of Mo in the Ni-ceria-zirconia appears to facilitate a higher degree of sintering for the anode, which increases the electronic conductivity and maximum power density of the single cell. Consequently, at 800 °C the single cell with 5 wt.% Mo in the Ni-ceria-zirconia-based anode displayed a higher maximum power density of 212 mW cm−2 at 0.48 V and significantly enhanced performance stability than the conventional Ni-YSZ anode single cell in the isooctane/air operating mode.

This paper describes an application of a NiMo-ceria-zirconia (NiMo-CZ) catalyst as a micro-reforming layer for solid oxide fuel cells running on isooctane (i.e., a gasoline surrogate). The catalyst layer was applied on top of a conventional anode supported single cell with a configuration of Ni-yttria-stabilized zirconia (YSZ) anode, YSZ/Ce0.8Sm0.2O1.9 bi-layer electrolyte and La0.6Sr0.4Co0.2Fe0.8O3-δ cathode. Our findings show that the application of the novel catalyst layer was an effective way to reform the mixture of isooctane and air into H2 and CO, which facilitated the electrochemical oxidation of complex hydrocarbons at the anode. At 750 °C, the single cell with the micro-reforming layer exhibited a low polarization resistance of 1.36 Ω cm2 and a maximum power density of 405 mW cm−2 in the direct feeding condition of an isooctane/air mixture. At the current density of 500 mA cm−2, the cell voltage presented a fairly low degradation rate of 3.0 mV h−1 during a 12 h stability test. The excellent electrochemical performance suggests the high catalytic activity of the NiMo-CZ catalyst layer for reforming isooctane and suppressing degradation of the single cell in the direct feeding of isooctane/air.

Catalytic reduction by the reverse water gas shift (RWGS) reaction is an efficient way to utilize carbon dioxide and reduce its environmental impact as a greenhouse gas. In this research, an active CuFe/Al 2 O 3 nano powder was developed as a high temperature reforming catalyst for the RWGS reaction. The powder was synthesized by a wet-impregnation method and the copper alloy was uniformly dispersed on the γ-Al 2 O 3 support. At a gas space velocity of 60,000 h −1 , the conversion of carbon dioxide was 42% at 700 °C, which is very close to the equilibrium conversion of 44%. The results indicated excellent reforming activity of the CuFe/Al 2 O 3 catalyst for the high temperature RWGS reaction. In addition, the catalyst was applied in the form of a reforming layer over a conventional Ni-based electrode of a solid oxide electrolysis cell (SOEC) for an integrated SOEC-RWGS system. Hydrogen produced from steam electrolysis over the Ni-based cathode can be efficiently utilized to reduce the carbon dioxide by the RWGS reaction over the CuFe/Al 2 O 3 -based reforming layer. In this bilayer design, the reforming layer maintained the high surface area necessary for achieving good reforming activity, while the electrode layer possessed a high degree of sintering to enhance its electrochemical function. A high conversion of carbon dioxide (37% at 700 °C) was obtained in our bilayer SOEC-RWGS system. This promising result suggests the feasibility of the integrated SOEC-RWGS system for an efficient co-electrolysis device.

A titanium-doped Ce 0.8 Sm 0.2 O 1.9 composite is developed as an anode component of low temperature solid oxide fuel cells running on methane fuel. Crystallographic parameters of (Ce 0.8-x Ti x )Sm 0.2 O 2-δ (0.00 0.8-x Ti x )Sm 0.2 O 2-δ composites are applied to an anode-supported single cell consisting of Ni-(Ce 0.8-x Ti x )Sm 0.2 O 2-δ anode/Ce 0.8 Sm 0.2 O 1.9 electrolyte/La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ cathode. Catalytic properties of Ni-(Ce 0.8-x Ti x )Sm 0.2 O 2-δ are inspected with the electrochemical performance and performance stability of the cells in dry methane fuel. The cell with Ni-(Ce 0.73 Ti 0.07 )Sm 0.2 O 2-δ (x = 0.07) anode displays a low polarization resistance and an optimum maximum power density (679 mW cm −2 at 600 °C). A performance stability investigation indicates that the cell exhibits a fairly low degradation rate of 3 mV h −1 during a 31 h operation in dry methane. These findings suggest the application potential of the titanium doped Ce 0.8 Sm 0.2 O 1.9 for the anode of solid oxide fuel cells.

This short communication describes a novel MoO2-based cathode and its potential application for solid oxide electrolysis cells. Electrochemical performances of the MoO2-based cathode are investigated with respect to a commercial Ni/YSZ-based cathode for both co-electrolysis (of H2O and CO2) and electrolysis of only CO2 at 750 °C. Under the co-electrolysis mode, the MoO2-based cell and the Ni/YSZ cell show a similar electrochemical performance, while in the CO2 electrolysis mode, the MoO2-based cell demonstrates a much improved electrocatalytic activity compared with the Ni/YSZ cell. This improved electrochemical activity of the MoO2-based cathode under the CO2 electrolysis mode is further investigated by its electrochemical impedance spectroscopy (EIS) study. According to our EIS study, the polarization resistance of the MoO2-based cell is 67% lower than that of the Ni/YSZ-based cell under the open circuit potential. A performance stability study indicates that the MoO2-based cell exhibits a relatively low performance degradation under the CO2 electrolysis mode during its 10-h constant voltage test, and low carbon amount (6.6 wt.%) is detected after the performance stability measurement. These findings suggest the advantages of applying the MoO2-based cathode for the CO2 electrolysis.

A NiMo–Ce0.5Zr0.5O2-δ (NiMo-CZ) catalyst has been developed for gasoline-fed solid oxide fuel cells (SOFCs). To apply the catalyst on a button-type single cell, the NiMo-CZ is deposited on top of conventional Ni-yttria-stabilized zirconia (YSZ) anode as a catalytic internal micro-reforming layer. The NiMo-CZ layer is effective in increasing the gasoline conversion and enhancing the yields of both H2 and CO at 750 °C. On the other hand, due to the high mechanical stress induced from the constrained sintering with a thicker catalyst layer, only a limited amount of catalyst (~20 mg) could be applied over the conventional button-type cell, which is not beneficial for enhancing overall cell performances. To overcome this issue, a tubular single cell configuration is adopted that allowed for higher catalyst loadings. By introducing higher catalyst loadings (~80 mg) in the vacant tubular channel of the single cell, the gasoline conversion, H2 yield, and CO yield all improve while cell lifetime increases by 42% compared to the performance of the button-type cell. The results suggest the potential of the NiMo-CZ catalyst for gasoline-fed SOFCs, and it demonstrates the advantage of the tubular single cell configuration for incorporating higher catalyst loadings for internal catalytic fuel reforming.

Tar produced by biomass gasification as a route of renewable energy must be removed before the gas can be used. This study was undertaken using toluene as a model tar compound for evaluating its steam reforming conversion with three Ni-based catalysts, Ni/olivine, Ni–Ce/olivine and Ni–Ce–Mg/olivine. Effects of Ce and Mg promoters on the reaction activity and coke deposition were studied. Overall the performance of Ce and Mg promoted Ni/olivine catalysts is better than that of only Ce promoter and Ni/olivine alone. The experimental results indicate that Ni–Ce–Mg/olivine catalysts could improve the resistance to carbon deposition, enhance energy gases yield and resist 10 ppm H 2 S poison at 100 mL min −1 for up to 400 min. Furthermore, the activity of catalysts was related to the steam/carbon (S/C) ratios; at S/C ratio = 5, T = 790 °C, space velocity = 782 h −1 and t = 2 h, the Ni–Ce–Mg/olivine system yielded 89% toluene conversion, 5.6 L h −1 product gas rate, 62.6 mol% H 2 content and 10% (mol useful gas mol −1 toluene) energy yield. Moreover, at low S/C ratio, it had higher reaction activity and better ability to prevent coking. There is a small amount of carbon deposition in the form of amorphous carbon after 7 h. Various characterization techniques such as XRD, FTIR and thermogravimetric were performed to investigate the coke deposition of Ni/olivine, Ni–Ce/olivine and Ni–Ce–Mg/olivine. It is suggested that 3% Ni-1% Ce-1% Mg/olivine was the most promising catalyst due to its minimum coke amount and the lower activation energy of coke burning.