Surface-enhanced Raman spectroscopy is one of the most sensitive spectroscopic techniques available, with single-molecule detection possible on a range of noble-metal substrates. It is widely used to detect molecules that have a strong Raman response at very low concentrations. Here we present photo-induced-enhanced Raman spectroscopy, where the combination of plasmonic nanoparticles with a photo-activated substrate gives rise to large signal enhancement (an order of magnitude) for a wide range of small molecules, even those with a typically low Raman cross-section. We show that the induced chemical enhancement is due to increased electron density at the noble-metal nanoparticles, and demonstrate the universality of this system with explosives, biomolecules and organic dyes, at trace levels. Our substrates are also easy to fabricate, self-cleaning and reusable.

Zinc anode-based batteries have been widely studied due to their low cost, high capacity and high energy density. However, the formation of dendrites on the zinc anode during cycling severely affects the stability and safety of this type of battery. In this work, a series of electrolyte additives with potential to counter this problem were studied. We found that lithium chloride (LiCl) additive can suppress the growth of dendrites and stabilize the Zn metal anode, on which the cations (Li + ) preferentially form Li2O/Li2CO3 upon the Zn surface and provide a shielding effect to suppress dendritic deposition, while a moderate amount of anions (Cl -) decrease the Zn polarization and facilitate ion transport.Asymmetric cells with LiCl additives in the electrolyte showed notably higher stability during the long cycling process.

14 15Exquisitely sensitive broadband detectors are needed to expand the capabilities of biomedical ultrasound, 30The sensitive detection of broadband ultrasound waves in the hundreds of kHz to tens of beam as required to achieve small element size for low directional sensitivity. 107The strong optical confinement afforded by the planoconcave microresonator design creates the opportunity 108 to maximise sensitivity in two ways. The first is by increasing the mirror reflectivity, trapping light for longer 109 and increasing the number of significant round trips in the cavity, leading to a higher Q-factor and thus a higher showing the 50% cut-off for the modelled response of a disk-shaped purely spatially averaging sensor of diameter 2mm. c, 161Directional response of 100μm sensor at selected frequencies as compared to the modelled response of a disk-shaped 162 spatially averaging receiver of diameter 2mm. For all data: w " = 12.5μm. 164Along with the NEP measurements in figure 1, the frequency response data in figure 2

Atmospheric pressure chemical vapor deposition of SnS 2 , Sn 2 S 3 , and SnS has been achieved onto glass substrates from the reaction of SnCl 4 with H 2 S at 300-545 °C. The films show good uniformity and surface coverage, adherence, and a variety of colors (black, yellow, brown, and gray) dependent on deposition temperature and film thickness. Growth rates were on the order of 1-2 µm min -1 . All the films were crystalline. For substrate temperatures of up to 500 °C single phase films with the hexagonal SnS 2 structure (a ) 3.65(1) Å, c ) 5.88(1) Å) were formed. At 525 °C a film of mixed composition containing predominantly orthorhombic Sn 2 S 3 (a ) 8.83(1) Å, b ) 3.76(1) Å, c ) 14.03(1) Å) was formed together with some SnS 2 . At 545 °C films with orthorhombic SnS structure (a ) 4.30(1) Å, b ) 11.20(1) Å, c ) 3.99(1) Å) were formed. Scanning electron microscopy (SEM) revealed a variety of different film thicknesses and morphologies, including needles, plates, and ovoids, dependent on the deposition temperature and time. Energy-dispersive X-ray analysis (EDX) and electron probe measurements on the films indicated elemental ratios close to those for tin disulfide (SnS 1.98 ), ditin trisulfide (SnS 1.60 ), and tin monosulfide (SnS 1.10 ) and revealed no incorporation of chlorine. X-ray photoelectron spectroscopy (XPS) gave results in agreement with those from EDX and revealed binding energies of Sn 3d 5/2 ) 486.5(1) eV and S 2p ) 161.6(2) eV for films grown at less than 500 °C (SnS 2 ), and Sn 3d 5/2 ) 485.7 (1) eV and S 2p 3/2 ) 161.0 eV for the film grown at 545 °C (SnS). Raman microscopy showed that the films of SnS 2 had bands at 315 and 215 cm -1 , those of Sn 2 S 3 had bands at 307, 251, 234, 183, 71, 60, and 52 cm -1 , and those of SnS had bands at 288, 220, 189, 163, and 96 cm -1 . The band gap of SnS 2 was 2.14 eV. Sheet resistance measurements showed that all of the films were essentially insulating.

fields such as healthcare, automotive, and aviation. Among them, flexible and wearable electronics exhibit a growing interest such as implantable medical devices, [1] wearable health monitoring systems, [1,2] flexible displays, [3] and smart clothes. [4] Conventional devices utilizing rigid and relatively unsafe lithium-ion batteries (LIBs) as the power supply cannot satisfy the future requirements of biocompatible and flexible features. Moreover, the bottleneck of flexible LIBs, such as the high cost, safety issues and intricate manufacturing requirements restrict the commercialization of flexible LIBs. As promising alternatives, aqueous zinc-ion batteries (AZIBs) have attracted a significant attention. They are regarded as competitive candidates for flexible devices owing to the high volumetric capacity (5855 mAh cm −3 ) of the zinc metal and its facile fabrication process. Meanwhile, the superior cost advantage, $25/kWh [5] for AZIBs comparing to $135/kWh [6,7] for LIBs, is beneficial to applying AZIBs in different scales of devices.Aqueous zinc ion batteries (AZIBs) currently suffer from unfavorable water-induced side reactions that result in zinc dendrite formation, dissolution of cathode materials and the formation of byproducts on cathodes, thus causing a fast capacity fade. Owing to the water electrolysis (stable Owing to the development of aqueous rechargeable zinc-ion batteries (ZIBs), flexible ZIBs are deemed as potential candidates to power wearable electronics. ZIBs with solid-state polymer electrolytes can not only maintain additional load-bearing properties, but exhibit enhanced electrochemical properties by preventing dendrite formation and inhibiting cathode dissolution. Substantial efforts have been applied to polymer electrolytes by developing solid polymer electrolytes, hydrogel polymer electrolytes, and hybrid polymer electrolytes; however, the research of polymer electrolytes for ZIBs is still immature. Herein, the recent progress in polymer electrolytes is summarized by category for flexible ZIBs, especially hydrogel electrolytes, including their synthesis and characterization. Aiming to provide an insight from lab research to commercialization, the relevant challenges, device configurations, and life cycle analysis are consolidated. As flexible batteries, the majority of polymer electrolytes exploited so far only emphasizes the electrochemical performance but the mechanical behavior and interactions with the electrode materials have hardly been considered. Hence, strategies of combining softness and strength and the integration with electrodes are discussed for flexible ZIBs. A ranking index, combining both electrochemical and mechanical properties, is introduced. Future research directions are also covered to guide research toward the commercialization of flexible ZIBs.

We report the synthesis and photoelectrochemical assessment of phase pure tetragonal matlockite structured BiOX (where X = Cl, Br, I) films.

No abstract

Surface area determination with the Brunauer–Emmett–Teller (BET) method is a widely used characterization technique for metal–organic frameworks (MOFs). Since these materials are highly porous, the use of the BET theory can be problematic. Several researchers have evaluated the BET method to gain insights into the usefulness of the obtained results and interestingly, their findings are not always consistent. In this review, the suitability of the BET method is discussed for MOFs that have a diverse range of pore widths below the diameters of N2 or Ar and above 20 Å. In addition, the surface area of MOFs that are obtained by implementing different approaches, such as grand canonical Monte Carlo simulations, calculations from the crystal structures or based on experimental N2, Ar, or CO2 adsorption isotherms, are compared and evaluated. Inconsistencies in the state‐of‐the‐art are also noted. Based on the current literature, an overview is provided of how the BET method can give useful estimations of the surface areas for the majority of MOFs, but there are some crucial and specific exceptions which are highlighted in this review.