Although photocatalytic overall water splitting is a potential technology for converting solar energy into chemical fuel, the widely reported solar‐to‐hydrogen efficiency is around 1%, indicating unsatisfactory photocatalytic performance. Here, a novel photocatalyst material is designed and a whole reaction system is constructed, resulting in an integrative photothermal–photocatalytic Z‐scheme overall water splitting reaction system. In terms of materials design, a novel sulfur‐deficient ZnIn2S4/oxygen‐deficient WO3 (ZIS–WO) hybrid with surface‐carbonized wood (C‐wood) is reported. The ZIS–WO hybrid with sulfur and oxygen vacancies promotes the adsorption of visible light and the separation of charge carriers. The conductive C‐wood is strategically used as an additional electron bridge to accelerate electron transfer. In terms of system construction, the C‐wood exploits the photothermal effect to change the solid/liquid/gas triphase system to a solid/gas biphase system by transforming liquid water into steam, which drastically restrains carrier recombination, and decreases the photocatalytic reaction barrier. The H2 and O2 production rates in the proposed system are approximately 169.2 and 82.5 µmol h–1 under air mass (AM) 1.5 light irradiation, and the corresponding solar‐to‐hydrogen efficiency is as high as 1.52%. The study from photocatalyst design to reaction system construct opens a new insight for versatile and high‐performance photocatalytic overall water splitting.
In this paper, we assume that the reserve level of an insurance company can only be observed at discrete time points, then a new risk model is proposed by introducing a periodic capital injection strategy and a barrier dividend strategy into the classical risk model. We derive the equations and the boundary conditions satisfied by the Gerber-Shiu function, the expected discounted capital injection function and the expected discounted dividend function by assuming that the observation interval and claim amount are exponentially distributed, respectively. Numerical examples are also given to further analyze the influence of relevant parameters on the actuarial function of the risk model.
An optimized approach to producing lattice‐matched heterointerfaces for electrocatalytic hydrogen evolution has not yet been reported. Herein, we present the synthesis of lattice‐matched Mo2C−Mo2N heterostructures using a gradient heating epitaxial growth method. The well lattice‐matched heterointerface of Mo2C−Mo2N generates near‐zero hydrogen‐adsorption free energy and facilitates water dissociation in acid and alkaline media. The lattice‐matched Mo2C−Mo2N heterostructures have low overpotentials of 73 mV and 80 mV at 10 mA cm−2 in acid and alkaline solutions, respectively, comparable to commercial Pt/C. A novel photothermal‐electrocatalytic water vapor splitting device using the lattice‐matched Mo2C−Mo2N heterostructure as a hydrogen evolution electrocatalyst displays a competitive cell voltage for electrocatalytic water splitting.
AlN thin film bulk acoustic resonators (FBARs) with a resonant frequency of $575 MHz have been fabricated to function as an epithelial tumor marker mucin 1 (MUC1) biosensor. Streptavidin was assembled on the sensitive area of FBAR. After the recognition between aptamers-AuNP conjugates and MUC1, biotin, along with the conjugates, was captured by streptavidin onto the surface of FBARs. Therefore, the target MUC1 could be sensitively detected. This biosensor exhibited a good linear relationship between the frequency shifts and the concentrations of MUC1 ranging from 30 to 500 nM, which indicated the sensitivity is about 818.6 Hz nM À1 . The frequency shift remained relatively stable when the concentration of MUC1 was greater than 500 nM since the binding between MUC1 and aptamers-AuNP conjugates reached saturation. The selectivity experiment demonstrated that this biosensor can precisely detect MUC1 with good specificity. The positive results suggest that FBAR is an attractive alternative to a new approach for the detection of MUC1.
A film buck acoustic resonator (FBAR) operated in shear mode was fabricated and integrated with a microchannel for detection of the carcinoembryonic antigens (CEA).
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