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Ag–Bi 2 WO 6 –TiO 2 (ABT) ternary composite photocatalyst was prepared using solvothermal and surface deposition method. Then, the nano photocatalyst was doped into the starch film liquid through internal loading method, and finally, ABT/starch composite film was constructed using tape casting method for visible light catalytic degradation of ethylene. Characterize and analyze the structure and physical properties of nano ABT/starch composite membranes prepared with different ABT loading amounts, and optimize the reaction conditions (ABT addition amount, light intensity, initial concentration of ethylene) on the visible light catalytic degradation performance for ethylene of the composite membrane. The results show that the nano ABT particles and starch molecules have good biocompatibility, and they can be well fused to form a film, without changing the crystal structure of ABT and generating other chemical bond. The results of photocatalytic degradation of ethylene showed that when the loading amount of ABT was 5 wt%, the light intensity was 60.5 mw/cm2, and the initial concentration of ethylene was 0.15 mg/L, the ABT/starch film had the best ethylene degradation performance, with a K′ value of 5.6111 × 10−4 min−1, which is 17.9 times that of the blank starch film. Under the optimal preparation conditions, the thickness, tensile strength, elongation at break of the starch composite film is 168.33 μm, 5.01 Mpa, 32.4%, respectively, and the maximum thermal decomposition temperature is 320.5 °C, which meets the requirements for food packaging materials. After 4 cycles, the catalytic degradation of ethylene by starch composite membrane only decreased by 13.98%, indicating good reusability. [ABSTRACT FROM AUTHOR]

Abstract Bi 2 WO 6 –TiO 2 (BT)/starch nanocomposite films were prepared by incorporating BT nano-particles through the casting method. The BT nano-particles used were synthesized by solvothermal method. The effects of BT loadings (0, 1, 2, 3, 4, and 5 wt% dry basis) on the optical, mechanical, microstructural, spectral, and thermal properties of the nanocomposite films were investigated, and their photocatalytic activities were evaluated from the degradation of ethylene under visible light. With the increase in BT loading, the tensile strength of the film specimens increased while elongation at break and transparency decreased; the nano-particle agglomerates increased when excess BT nano-particles were added into the films. When the loading was 4%, the film exhibited the highest photocatalytic activity, and the rate of ethylene degradation reached 12.47%. In conclusion, the BT/starch films can effectively degrade ethylene in gaseous phase, and they have the potential to be used as fruit and vegetable packaging materials. Highlights • A fresh-keeping packaging material was fabricated using starch and Bi 2 WO 6 -TiO 2 (BT). • The BT/starch films exhibited good photocatalytic activity for ethylene degradation. • The BT heterostructure with firm and effective contact was formed in the films. • Tensile strength of the films were enhanced by loading BT. [ABSTRACT FROM AUTHOR]

P25/Bi 2 WO 6 nanocomposite photocatalysts were synthesized by solvothermal method, and their photocatalytic activities were evaluated for the degradation of ethylene under visible light irradiation. The results show that P25/Bi 2 WO 6 nanocomposites have higher photocatalytic activity than P25 and pure Bi 2 WO 6 . When the loading amount of P25 is 35%, the photocatalytic degradation of ethylene under visible light is the highest, which is 4.5 and 2.2 times higher than that of P25 and Bi 2 WO 6 , respectively. The improvement of the photocatalytic activity of the nanocomposite is mainly due to the formation of the staggered heterojunctions in the contact interface of P25 and Bi 2 WO 6 . This can refine the grain and produce lattice defects in the interface of the composite, which could provide more active sites. Therefore, the separation efficiency of the photogenerated electron-hole pair is improved, and the spectral response range is extended to the visible light region, thereby the absorption and utilization of light energy is improved. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ABT/starch composite film was prepared for catalytic degradation of ethylene. • The ABT produces a multiple electron transfer channels under visible light. • The Ag-Bi 2 WO 6 -TiO 2 ternary catalyst enhanced the absorption of visible light. • Starch film acts as an excellent carrier and is suitable for food-packaging. A novel Ag-Bi 2 WO 6 -TiO 2 (ABT) ternary photocatalyst was synthetized using a surface deposition and solvothermal method and its composite starch films with different amounts of ABT loading were prepared via a casting method. The morphology and microstructure of the ABT/starch composite films were characterized and their photocatalytic activity during the degradation of ethylene were evaluated. The results showed that the ABT photocatalyst exhibits excellent photocatalytic activity for the removal of ethylene under visible light with the maximum mineralization rate of 96% and CO 2 production of 0.81 × 10-4. Compared with that of pure TiO 2 , Bi 2 WO 6 and Bi 2 WO 6 -TiO 2 composite, the reaction rate constant (k') of ABT was improved by 188.13, 150.51, and 64.62%, respectively. When the surface loading of ABT was 2%, the photocatalytic performance of the ABT/starch film under visible-light reached its maximum with k' increasing by 61.8% compared with the starch film without ABT loading on the surface. The improvement in the photocatalytic activity was attributed to the synergistic effect of nano-Ag, TiO 2 and Bi 2 WO 6. Ag nanoparticles are anchored on the Bi 2 WO 6 -TiO 2 heterojunction, which increases the number of reactive active sites, broadens the absorption of visible light and produces more active species ·O 2 – and · OH, thus enhancing the photocatalytic performance. The cooperative synergy over as-prepared ABT formed by multiple electron transfer channels composed of localized surface plasmon resonance (LSPR) enhancement, Z-sheme charge transfer and electronic sink effect results in effective charge separation and inhibits the recombination of photogenerated carriers, thus exhibiting exceptional photocatalytic activity. [ABSTRACT FROM AUTHOR]