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Metal phthalocyanine (MPc) sensitized TiO2 represents a promising strategy for solar energy applications, but the MPc/TiO2 heterostructures still suffer from low MPc loading and limited photocatalytic efficiency for water purification. Here we simultaneously alleviate these constraints by anchoring iron phthalocyanine (FePc)/TiO2 heterostructure onto an amidoximated polyacrylonitrile (PAN) fiber through coordination bonds. The fibrous ligands enabled high FePc loading without obvious aggregation, and an optimal FePc/TiO2 ratio with 10.2% was obtained to give the best photocatalytic activity for organic contaminants degradation. The fibrous support not only offered more efficient electron injection process from FePc to TiO2, but also enhanced the adsorption capability towards organic contaminants and boosted the activation of photoinduced H2O2 by FePc. These synergistic qualities result in over 30-fold higher reaction kinetics at the fibrous interface versus a corresponding system with FePc/TiO2 powder catalysts. Our findings should be not limited to the current heterostructures and might provide a facile and promising path for the development of efficient composite photocatalysts with high performance.

Carrot appearance quality is an essential indicator for carrot sorter, so it is crucial to identify carrot appearance quality in carrot processing accurately. This paper proposed an innovative carrot appearance detection method, using a convolutional neural network to extract image feature information, and a support vector machine for classification. Firstly, the deep features based on 12 models were utilized for training the support vector machine. The deep features of the three-layer full connection layer of the network models (AlexNet, VGG16, VGG19) were extracted and imported into the support vector machine. The results showed that: (1) The accuracy of deep features with SVM were superior to the transfer learning models, and the average accuracy had increased by 1.42%. (2) The accuracy of the three models (AlexNet, VGG16, VGG19) based on the initial full connection layer was 98.13%, 98.06%, and 97.88%, respectively. The best model was ResNet101 + SVM, which had a recognition accuracy of 98.17%. So, this method has positive significance for the development of carrot sorter.

Dye sensitization represents a promising route to address the limited photoabsorption in semiconductor photocatalysis. However, efficient water purification using dye-sensitized photocatalysts has remained an unmet challenge. Here we report a novel strategy to promote dye-sensitized photocatalysis by combining the advantages of interfacial Fenton reaction construction and air-liquid-solid triphase contact. An alveoli-like Janus membrane was developed with bilayer electrospun micro/nanofibers, where the outer layer is hydrophilic semiconductor catalyst sensitized by an iron (II) phthalocyanine (FePc) photosensitizer, which can also act as the trigger of H2O2 activation; the hydrophobic internal layer serves as a gas passage to deliver O2 from air to the catalytic interface, boosting the photoinduced electrons conversion and H2O2 generation. This architecture allows a superior level of photosensitizer decoration when using TiO2 as the model semiconductor catalyst, which corresponds to highly efficient activity for photodegradation of organic contaminations accompanied with a high apparent quantum yield at around 660 nm. Our work may provide new insights into the development of high-efficiency solar driven photocatalysts for widespread applications.

TiO2 holds great promising for addressing the environmental issues via solar-to-chemical energy conversion. However, the large-scale application is greatly limited by its poor optical response (below 400 nm). In this study, we have successfully synthesized a visible light driven TiO2 catalyst via a facile hydrothermal route by using amidoximated polyacrylonitrile (PAN) fiber as the support for the first time. The fibrous bidentate ligands not only facilitated the visible light harvesting of TiO2 through ligand-to-metal charge transfer (LMCT) sensitization but also realized the incorporation of N atoms into the TiO2 lattice during the preparation. Such a unique architecture endows the TiO2 with high photocatalytic activity for degradation of several emerging organic contaminations under visible light irradiation (λ > 420 nm), which is dictated by both LMCT and N-doping mechanism. Furthermore, the fibrous support shows high resistance to active oxidizing species and imparts the as-prepared catalyst with excellent cycling stability, demonstrating the robustness of the constructed photocatalytic system for long-term applications. Our findings may offer a new strategy for designing promising visible-light-driven photocatalysts for environmental remediation.