Synthesis and photocatalytic property of Au-TiO2 nanocomposites with controlled morphologies in microfluidic chips.

We present an efficient approach for the consecutive synthesis of Au-TiO2 nanocomposites with controlled morphologies in a microfluidic chip. The seed-mediated growth method was employed to synthesize Au nanorods as the core, and TiO2 layers of varying thicknesses were deposited on the surface or tip of the Au nanorods. Au-TiO2 nanocomposites with core-shell, dumbbell, and dandelion-like structures can be precisely synthesized in a one-step manner within the microfluidic chip by finely tuning the flow rate of NaHCO3 and the amount of hexadecyl trimethyl ammonium bromide. Furthermore, we have investigated the photocatalytic activity of the synthesized nanocomposites, and it was found that Au NR-TiO2 core-shell nanostructure with a thin TiO2 shell exhibits superior catalytic performance. This work provides an effective and controlled method for the microscale preparation and photocatalytic application of various Au-TiO2 nanocomposite structures.

Fundamentals and Recent Progress in Magnetic Field Assisted CO2 Capture and Conversion.

CO2 capture and conversion technology are highly promising technologies that definitely play a part in the journey towards carbon neutrality. Releasing CO2 by mild stimulation and the development of high efficiency catalytic processes are urgently needed. The magnetic field, as a thermodynamic parameter independent of temperature and pressure, is vital in the enhancement of CO2 capture and conversion process. In this review, the recent progress of magnetic field-enhanced CO2 capture and conversion is comprehensively summarized. The theoretical fundamentals of magnetic field on CO2 adsorption, release and catalytic reduction process are discussed, including the magnetothermal, magnetohydrodynamic, spin selection, Lorentz forces, magnetoresistance and spin relaxation effects. Additionally, a thorough review of the current progress of the enhancement strategies of magnetic field coupled with a variety of fields (including thermal, electricity, and light) is summarized in the aspect of CO2 related process. Finally, the challenges and prospects associated with the utilization of magnetic field-assisted techniques in the construction of CO2 capture and conversion systems are proposed. This review offers a reference value for the future design of catalysts, mechanistic investigations, and practical implementation for magnetic field enhanced CO2 capture and conversion.

Photothermal CO-PROX reaction over ternary CuCoMnOx spinel oxide catalysts: the effect of the copper dopant and thermal treatment.

The purification of carbon monoxide in H2-rich streams is an urgent problem for the practical application of fuel cells, and requires the development of efficient and economical catalysts for the preferential oxidation of CO (CO-PROX). In the present work, a facile solid phase synthesis method followed by an impregnation method were adopted to prepare a ternary CuCoMnOx spinel oxide, which shows superior catalytic performance with CO conversion of 90% for photothermal CO-PROX at 250 mW cm-2. The dopant of copper species leads to the incorporation of Cu ions into the CoMnOx spinel lattice forming a ternary CuCoMnOx spinel oxide. The appropriate calcination temperature (300 °C) contributes to the generation of abundant oxygen vacancies and strong synergetic Cu-Co-Mn interactions, which are conducive to the mobility of oxygen species to participate in CO oxidation reactions. On the other hand, the highest photocurrent response of CuCoMnOx-300 also promotes the photo-oxidation activity of CO due to the high carrier concentration and efficient carrier separation. In addition, the in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) confirmed that doping copper species could enhance the CO adsorption capacity of the catalyst due to the generation of Cu+ species, which significantly increased the CO oxidation activity of the CuCoMnOx spinel oxide. The present work provides a promising and eco-friendly solution to remove the trace CO in H2-rich gas over CuCoMnOx ternary spinel oxide with solar light as the only energy source.

Thermoresponsive Lignin-Reinforced Poly(Ionic Liquid) Hydrogel Wireless Strain Sensor.

To meet critical requirements on flexible electronic devices, multifunctionalized flexible sensors with excellent electromechanical performance and temperature perception are required. Herein, lignin-reinforced thermoresponsive poly(ionic liquid) hydrogel is prepared through an ultrasound-assisted synthesized method. Benefitting from the electrostatic interaction between lignin and ionic liquid, the hydrogel displays high stretchability (over 1425%), excellent toughness (over 132 kPa), and impressive stress loading-unloading cyclic stability. The hydrogel strain sensor presents excellent electromechanical performance with a high gauge factor (1.37) and rapid response rate (198 ms), which lays the foundation for human body movement detection and smart input. Moreover, owing to the thermal-sensitive feature of poly(ionic liquid), the as-prepared hydrogel displays remarkable thermal response sensitivity (0.217°C-1) in body temperature range and low limit of detection, which can be applied as a body shell temperature indicator. Particularly, the hydrogel can detect dual stimuli of strain and temperature and identify each signal individually, showing the specific application in human-machine interaction and artificial intelligence. By integrating the hydrogel strain sensor into a wireless sensation system, remote motion capture and gesture identification is realized in real-time.

[Trophic niche partitioning of four pelagic shark species in the tropical Atlantic based on multi-tissue stable isotopes ratios]. / åŸºäºŽå¤šç»„ç»‡ç¨³å®šåŒä½ç´ æ¯”å€¼çš„çƒ­å¸¦å¤§è¥¿æ´‹4ç§é²¨é±¼è¥å »ç”Ÿæ€ä½åˆ†åŒ–.

Stable carbon and nitrogen isotope ratios (δ13C and δ15N, respectively) of multiple tissues with different turnover rates can provide trophic information at different timescales, and thus play an important role in tracing the changes of feeding, habitat utilization and trophic niche of consumers. The δ13C and δ15N contents of muscle, liver and blood of blue sharks (Prionace glauca), longfin mako sharks (Isurus paucus), crocodile sharks (Pseudocarcharias kamoharai) and shortfin mako sharks (I. oxyrinchus) from tropical Atlantic were measured, and the trophic niche was evalua-ted. The results showed that I. oxyrinchus, P. kamoharai, and P. glauca had similar δ15N values, higher than that of I. paucus. Feeding segregation was found between P. glauca and other species, showing unique trophic niche. The largest trophic niche width was observed in I. oxyrinchus, indicating the high diversity of prey and (or) feeding habitats. High trophic niche overlap was found in P. kamoharai and I. oxyrinchus, implying their potential competition for resources. There was no correlation between the differences among tissues in the δ13C or δ15N values and the body size of I. oxyrinchus, P. kamoharai and P. glauca, indicating no recent diet shifts for those species. I. paucus showed significant correlation between δ15N differences in liver, blood and muscle with the shark fork length, indicating its short-term diet shift. The similarity of δ13C and δ15N values and the higher metabolic rates of liver and blood were found in all four shark species, implying the similar incorporation rates of both tissues, which were considered as the short-term indicator of diet.

A three-dimensional CoNi-MOF nanosheet array-based immunosensor for sensitive monitoring of human chorionic gonadotropin with core-shell ZnNi-MOF@Nile Blue nanotags.

A CoNi-based metal-organic framework (CoNi-MOF) nanosheet array is synthesized by the treatment of a CoNi layered double hydroxide nanosheet array on Ni foam with 3,5-diaminobenzoic acid. The CoNi-MOF nanosheet array with amino and carboxyl groups can be used to capture the human chorionic gonadotropin (HCG) primary antibody (HCG Ab1). Nile Blue decorated ZnNi-MOF (NB@ZnNi-MOF) spheres immobilized with HCG secondary antibodies (HCG Ab2) are used for signal amplification. When HCG exists in an analytical sample, a sandwich structure is formed and an electrochemical signal is produced. The analytical signal generated during the detection is caused by the conversion of Co(ii) and Co(iii) in the CoNi-MOF nanosheet array. The Nile Blue of the NB@ZnNi-MOF sphere, as a kind of redox-active species, is responsible for the electrochemical signal amplification in the immunosensor. On the basis of the above advantages, the HCG immunosensor exhibits a lower limit of detection (1.85 × 10-3 mIU mL-1) and a wide linear range from 0.005 mIU mL-1 to 250 mIU mL-1. Additionally, this immunosensor is used to quantitatively detect HCG in human blood serum and shows good correlations with the standard enzyme-linked immunosorbent assay (ELISA), providing a high value on clinical diagnosis.

Copper(II) 1,4-naphthalenedicarboxylate on copper foam nanowire arrays for electrochemical immunosensing of the prostate specific antigen.

Nanowires of copper(II)-based metal-organic frameworks (Cu-MOFs) of type Cu(II)(1,4-naphthalenedicarboxylic acid) (1,4-NDC) were deposited on the surface of a copper foam by immersion of Cu(OH)2 nanowires in a solution of 1,4-NDC. An electrochemical immunosensor for the prostate specific antigen (PSA) is obtained by using the nanowire arrays as a redox signal probe. The signal is generated by the conversion of Cu(I) and Cu(II) of Cu-MOFs nanowires. Cu(1,4-NDC) nanowires contain many uncoordinated carboxyl groups which can bind to the amino groups of the PSA antibody. When PSA antibody binds to PSA antigen during an immune response, the current signal will decrease due to the electrical insulation of PSA antigen. The decrease of current is directly proportional to the increase of PSA concentration. The immunosensor, best operated at a voltage of typically -0.08 V (vs. Ag/AgCl), has a low limit of detection (4.4 fg·mL-1) and a wide linear range (0.1 pg·mL-1 to 20 ng·mL-1). This meets the demands of clinical diagnosis (with values <4 ng·mL-1) in serum. The method was applied to the determination of PSA in spiked serum. Graphical abstractSchematic representation of the in-situ growth of ordered Cu-MOFs wrapped with Cu(OH)2 nanowires, building the core-shell structure as the 3D electrode. A novel electrochemical immunosensor for PSA detection has been exploited, using the Cu-MOFs nanowire arrays on Cu foam as a redox signal probe for the first time.

Ultrathin nickel-metal-organic framework nanobelt based electrochemical sensor for the determination of urea in human body fluids.

Ultrathin nickel-metal-organic framework (Ni-MOF) nanobelts, [Ni20(C5H6O4)20(H2O)8]·40H2O (Ni-MIL-77), have been exploited successfully for the fabrication of a non-enzymatic urea sensor. Ni-MOF ultrathin nanobelts in alkaline media can be used as an efficient catalyst for urea electrooxidation. As a non-enzymatic urea sensor, Ni-MOF ultrathin nanobelts exhibit a high sensitivity of 118.77 µA mM-1 cm-2, wide linear range of 0.01-7.0 mM, and low detection limit of 2.23 µM (S/N = 3). The selectivity, stability and reliability of ultrathin Ni-MOF nanobelts towards urea oxidation are also investigated. Moreover, Ni-MOF ultrathin nanobelts were further used to detect urea in human body fluids. All these findings confirm that the urea sensor based on Ni-MOF ultrathin nanobelts is successfully prepared and promising for applications in medical diagnostics and environmental monitoring.