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Recently， approximately 20% of the products unqualified in the national sampling inspection of imported food have been found through food label inspection， which has become one of the most important inspection methods for imported prepackaged food. In this study， the labels of imported prepackaged food were analyzed to determine the important inspection points， noting that particular attention should be paid to the conformity of products with the entry and registration requirements of the general administration of customs， the use of compliant raw materials， and the standardization of the special labeling content. The results suggest that the quality and efficiency of label inspection should be improved from four aspects： enhancing the awareness and ability to prevent and control unqualified risks， strengthening the training of inspectors’ professional skills， developing an artificial intelligence label verification system， and optimizing the relevant laws and standards to improve the safety of imported prepackaged food.

CuBi2O4 is a promising p-type semiconductor material with a theoretical maximum current density of about 19.7 mA cm‒2. Although CuBi2O4 has a very high theoretical photocurrent, its poor charge transmission efficiency makes its actual photocurrent far less than its theoretical values. Herein, an in situ modification method is adopted to prepare a photocathode material with Ag as conductive channels. A metal–organic coating method is used to introduce Ag conductive channels, promoting the charge transmission between grains. Ag particles play the role of electrical connection, and improve the separation and transmission of carriers, so as to obtain enhanced photocurrent density. In situ formed Ag conductive channels significantly enhanced the PEC performance of CuBi2O4 photocathodes. [ABSTRACT FROM AUTHOR]

Passivating surface traps plays a crucial role in mitigating the efficiency loss of solar water-splitting electrodes. However, the associated surface-trap passivation approaches require the introduction of an overlayer, complicating the fabrication process and increasing the capital cost of photoelectrodes. Herein, using CuBi2O4 as a prototype, an in situ surface-trap passivation strategy is developed, which yields a beneficial 90 mV anodic shift in hydrogen-evolution onset. Detailed mechanism investigations prove that the intentionally added Mg2+ ions in the precursor gradually segregate as MgO and enrich at the grain boundaries/surface of the CuBi2O4 multicrystalline, porous film during annealing, via which surface traps stemming from dangling bonds are spontaneously passivated; measurements of photovoltage generation characteristics and carrier lifetime validate the favorable roles of the MgO passivator in CuBi2O4 photocathodes. A bias-free water-splitting device is assembled using MgO-passivated CuBi2O4 and Mo-doped BiVO4 as the photocathode and photoanode respectively in a tandem configuration, delivering a solar-to-hydrogen conversion efficiency of approximately 0.41%. [ABSTRACT FROM AUTHOR]

Exploring cheap and efficient cocatalysts is particularly important for a photoanode during photoelectrochemical (PEC) water splitting. Herein, we demonstrate that composite CoOx/CuO cocatalyst could efficiently enhance the oxygen evolution activity of BiVO4. The onset potential of BiVO4 shifts negatively from 0.42 to 0.38 V vs. the reversible hydrogen electrode (RHE), and the photocurrent of BiVO4 increases from 0.42 mA cm−2 to 1.58 mA cm−2 at 1.23 V vs. RHE, which increases by about 3.76 times. It was confirmed by subsequent electrochemical and physical characterization that the charge separation and injection efficiency were improved, and the IPCE was also improved. Systematic studies indicate that composite CoOx/CuO cocatalyst exhibits better performance than the single CoOx or CuO cocatalyst for promoting the separation of electron‐hole, and accelerating the surface water oxidation reaction. [ABSTRACT FROM AUTHOR]

Photocatalytic removal of hexavalent chromium (Cr(VI)) based on semiconductor is important under visible light for environment and energy. Herein, a visible light-responsive heterojunction composed of molybdenum disulfide and zinc indium sulfide was synthesized through a simple one-pot hydrothermal method to ensure full contact between the two components to efficiently improve the Cr(VI) reduction. The MoS2/ZnIn2S4 composites build heterojunctions between MoS2 and ZnIn2S4 to inhibit recombination of photogenerated holes and electrons and provide the reaction sites to trap photogenerated electrons to participate in the reduction of Cr(VI). The highly efficient reduction of Cr(VI) was obtained by adjusting the proportion of molybdenum disulfide. It demonstrates that the 0.5 wt% MoS2/ZnIn2S4 composite microstructures show the highest degradation rate of 0.1989 s−1 under visible light irradiation, 1.7 times of bare ZnIn2S4. Moreover, the MoS2/ZnIn2S4 showed excellent stability during photocatalytic recyclable processes. This work encourages researchers to remove Cr(VI) by constructing effective heterojunction structures. [ABSTRACT FROM AUTHOR]