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A method to suppress the photocorrosion of ZnO nanoparticles was developed by surface hybridization of ZnO with graphite-like carbon layers. The presence of carbon on the surface of the ZnO could significantly suppress the coalescence and crystal growth of ZnO nanoparticles during high-temperature treatment. The nanosized structure of ZnO was well preserved even after high-temperature calcination. The photocatalytic activity of ZnO was enhanced by hybridization with carbon layers attributed to the improved adsorption ability and crystallinity. The as-prepared samples exhibited high activity even after 720 h of photocatalysis reaction, while the pure ZnO nanoparticle was almost deactivated in 100 h due to serious photocorrosion. The as-prepared samples also showed much better activity under extreme pH conditions than that of pure ZnO. The mechanism of photocorrosion suppression and higher stability was then systematically investigated based on the crystal structure and the photocatalysis degradation process.

Micro- and nanoplastics are considered one of the top pollutants that threaten the environment, aquatic life, and mammalian (including human) health. Unfortunately, the development of uncomplicated but reliable analytical methods that are sensitive to individual microplastic particles, with sizes smaller than 1 μm, remains incomplete. Here, we demonstrate the detection and identification of (single) micro- and nanoplastics by using surface-enhanced Raman spectroscopy (SERS) with Klarite substrates. Klarite is an exceptional SERS substrate; it is shaped as a dense grid of inverted pyramidal cavities made of gold. Numerical simulations demonstrate that these cavities (or pits) strongly focus incident light into intense hotspots. We show that Klarite has the potential to facilitate the detection and identification of synthesized and atmospheric/aquatic microplastic (single) particles, with sizes down to 360 nm. We find enhancement factors of up to 2 orders of magnitude for polystyrene analytes. In addition, we detect and identify microplastics with sizes down to 450 nm on Klarite, with samples extracted from ambient, airborne particles. Moreover, we demonstrate Raman mapping as a fast detection technique for submicron microplastic particles. The results show that SERS with Klarite is a facile technique that has the potential to detect and systematically measure nanoplastics in the environment. This research is an important step toward detecting nanoscale plastic particles that may cause toxic effects to mammalian and aquatic life when present in high concentrations.

However, the band gap of TiO 2 is larger than 3.0 eV, which means it can only show activity under UV irradiation. Thus, the commercialization of this technology has been hindered. [3] Anion-doping with N, C, and S or cation-doping with transition metals are commonly used to functionalize TiO 2 as a visible-light photocatalyst.[4] However, these doped TiO 2 materials show low absorption of visible light; moreover, their photocatalytic activities are still very low, due to complicated factors. The development of efficient visible-light-active photocatalysts has been an urgent issue from the viewpoint of using solar energy.Pioneering work done by Zou et al.[5] displayed water-splitting for H 2 and O 2 evolution in a stoichiometric amount over the NiO x /In 0.9 Ni 0.1 TaO 4 photocatalyst under visible-light irradiation. Following this work, many new visible-active catalysts have been reported, such as Bi 2 WO 6 , [6] BiVO 4 , [7] CaBi 2 O 4 , [8] and InVO 4 .[9]These new ternary metal oxide semiconductors show great potential in the utilization of solar energy. These photocatalysts are usually utilized as suspended powders. However, the limitation of the low photocatalytic efficiency and the laborious recollection of the powders have considerably restricted their applications. In order to overcome the obstacles, porous TiO 2 films on solid supports have been developed.[10] Porous TiO 2 materials exhibit a large specific surface area, high porosity, and excellent photocatalytic performace. Unfortunately, to the best of our knowledge, there are still no reports focused on the highly porous films of visible-lightactive ternary metal oxide photocatalysts.In this communication, we describe a strategy for extending the general methodology of template-directed synthesis to the formation of porous ternary metal oxides. We present for the first time a simple and reproducible route to ordered porous Bi 2 WO 6 films with open pores, as an example of a photocatalytically active ternary metal oxide under visible-light irradiation. The photocatalytic activity of the as-prepared porous films was evaluated by the decomposition of methylene blue (MB) under visible light (l > 420 nm) irradiation: ordered porous Bi 2 WO 6 films exhibited a much higher photocatalytic activity and photocurrent coversion efficiency than nonporous Bi 2 WO 6 films.Scheme 1 outlines the typical synthesis of ordered porous Bi 2 WO 6 films. The preparation is performed by combining evaporation-induced self-assembly and the amorphous complexprecursor method. By using surfactants, block copolymers, or colloid spheres as the templates, porous sigle-phase oxide films have been obtained by hydrolysis of metal alkoxides, such as SiO 2 , TiO 2 , ZrO 2 , and so on.[11] From the viewpoint of developing an economical, preferentially solution-based route to porous ternary metal oxide films, in the current work an amorphous complex precursor was prepared and utilized instead of the metal alkoxide. The homogenous amorphous complex precursor was produced by complexatio...

Many important chemical transformations occur in two-phase reactions, which are widely used in chemical, pharmaceutical, and polymer manufacturing. We present an efficient method for performing two-phase reactions in microdroplets sheared by sheath gas without using a phase-transfer catalyst. This avoids disadvantages such as thermal instability, high cost, and, especially, the need to separate and recycle the catalysts. We show that various alcohols can be oxidized to the corresponding aldehydes and ketones within milliseconds in moderate to good yields (50-75 %). The scale-up of the present method was achieved at an isolated rate of 1.2 mg min for the synthesis of 4-nitrobenzylaldehyde from 4-nitrobenzyl alcohol in the presence of sodium hypochlorite. The biphasic nature of this process, which avoids use of a phase-transfer catalyst, greatly enhances synthetic effectiveness.

Reported here is the first on‐demand electrochemical epoxidation incorporated into the standard nano‐electrospray ionization mass spectrometry (nanoESI‐MS) workflow for double‐bond identification. The capability lies in a novel tunable electro‐epoxidation of double bonds, where onset of the reaction can be controlled by simply tuning the spray voltage. On‐demand formation of mono‐/multiple epoxides is achieved at different voltages. The electro‐epoxidized products are then fragmented by tandem MS to generate diagnostic ions, indicating the double bond position(s). The process is completed within seconds, holding great potential for high‐throughput analysis. The rapid switch‐on/off electro‐epoxidation of a single sample, the low sample consumption, the demonstrated applicability to complex lipids containing multiple double bonds, and the advantage of not requiring extra apparatus make this method attractive for use in lipid‐related biological studies.

Summary Recently, the environmental impacts of microplastics have received extensive attention owing to their accumulation in the environment. However, developing efficient technology for the control and purification of microplastics is still a big challenge. Herein, we investigated the photocatalytic degradation of typical microplastics such as polystyrene (PS) microspheres and polyethylene (PE) over TiO 2 nanoparticle films under UV light irradiation. TiO 2 nanoparticle film made with Triton X-100 showed complete mineralization (98.40%) of 400-nm PS in 12 h, while degradation for varying sizes of PS was also studied. PE degradation experiment presented a high photodegradation rate after 36 h. CO 2 was found as the main end product. The degradation mechanism and intermediates were studied by in situ DRIFTS and HPPI-TOFMS, showing the generation of hydroxyl, carbonyl, and carbon-hydrogen groups during the photodegradation of PS. This study provides a green and cost-efficient strategy for the control of microplastics contamination in the environment.

In recent years, bioanalytical surface-enhanced Raman spectroscopy (SERS) has blossomed into a fast-growing research area. We present here a review on SERS-based assays with focus on early bacterial infection detection and chronic disease diagnosis.