No abstract

Carrier transport is an equally decisive factor as carrier separation for elevating photocatalytic efficiency. However, limited by indefinite structures and low crystallinities, studies on enhancing carrier transport of organic photocatalysts are still in their infancy. Here, we develop an σ-linkage length modulation strategy to enhance carrier transport in imidazole-alkyl-perylene diimide (IMZ-alkyl-PDI, corresponding to D-σ-A) photocatalysts by controlling π-π stacking distance. Ethyllinkage can shorten π-π stacking distance (3.19 Å) the most among IMZ-alkyl-PDIs (where alkyl = none, ethyl, and n-propyl) via minimizing steric hindrance between D and A moieties, which leads to the fastest carrier transport rates. Thereby, IMZ-ethyl-PDI exhibits remarkable enhancement in phenol degradation with 32fold higher rates than IMZ-PDI, as well as the oxygen evolution rate (271-fold increased). In microchannel reactors, IMZ-ethyl-PDI also presents 81.5 % phenol removal with high-flux surface hydraulic loading (44.73 L m À 2 h À 1 ). Our findings provide a promising molecular design guideline for high-performance photocatalysts and elucidate crucial internal carrier transport mechanisms.

Elastomers that combined excellent mechanical performance and healability are essential to the advancement of stretchable electronics. However, the strength and toughness of healable elastomers tend to be mutually exclusive. Herein, a new strategy of the dynamic integrated moiety is developed to construct covalent and noncovalent cross-linked polyurethane (CNPU) elastomers. The covalent and noncovalent interactions synergistically enhance the overall mechanical properties of polyurethane elastomers such as tensile strength (48.8 MPa), toughness (282.9 MJ·m–3), stretchability (1740%), and healing efficiency (116%). Finally, elastic conductive wires are fabricated with high load capacity, stable electrical conductivity under static/dynamic stretching, and robust healability to demonstrate the potential use of CNPU elastomers in stretchable electronics.

Carrier transport is an equally decisive factor as carrier separation for elevating photocatalytic efficiency. However, limited by indefinite structures and low crystallinities, studies on enhancing carrier transport of organic photocatalysts are still in their infancy. Here, we develop an σ‐linkage length modulation strategy to enhance carrier transport in imidazole‐alkyl‐perylene diimide (IMZ‐alkyl‐PDI, corresponding to D‐σ‐A) photocatalysts by controlling π–π stacking distance. Ethyl‐linkage can shorten π–π stacking distance (3.19 Å) the most among IMZ‐alkyl‐PDIs (where alkyl=none, ethyl, and n‐propyl) via minimizing steric hindrance between D and A moieties, which leads to the fastest carrier transport rates. Thereby, IMZ‐ethyl‐PDI exhibits remarkable enhancement in phenol degradation with 32‐fold higher rates than IMZ‐PDI, as well as the oxygen evolution rate (271‐fold increased). In microchannel reactors, IMZ‐ethyl‐PDI also presents 81.5 % phenol removal with high‐flux surface hydraulic loading (44.73 L m−2 h−1). Our findings provide a promising molecular design guideline for high‐performance photocatalysts and elucidate crucial internal carrier transport mechanisms.

There is an increasing interest in tea polyphenols, as natural plant compounds, in food products and also in pharmaceutical products due to their multiple health care functions. In this paper, a microwave-assisted extraction method was employed for the extraction of tea polyphenols. The effects of microwave power, heating time, and ethanol concentration on extraction of tea polyphenols were investigated by single factor experiments and an orthogonal experiment [L9(3)3]. Results showed that the optimum extraction conditions were that the microwave power was 560W, the heating time was 30s, and the ethanol concentration was 40% (v/v). The antimicrobial properties of tea polyphenols were also discussed. Tea polyphenols had bacteriostatic activity against Escherichia coli and Staphylococcus aureus. This study may be valuable for the extraction and application of tea polyphenols.