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The rational design and construction of p-n heterojunctions were deemed as an efficient strategy for promoting the separation and migration of photogenerated electron-hole pairs. Here, a facile in-situ deposition process was applied to develop a novel dual-functional Ag2O quantum dot/ZnIn2S4 nanosheet (AO/ZIS) composite photocatalyst, which assisted to the uniform distribution of Ag2O quantum dots on the surfaces of ZnIn2S4 nanosheets for the fabrication of the unique p-n heterostructure. The as-prepared AO/ZIS hybrids presented significantly enhanced photocatalytic performance for both hydrogen generation and tetracycline hydrochloride (TCH) decomposition. The results indicated that sample AO/ZIS-2 possessed the highest photocatalytic H2 production capacity (2334.19 μmol·g−1) and TCH photodegradation rate (1.62 × 10−2 min−1), which were 3.38 and 3.82 times as high as those of bare ZnIn2S4. Meanwhile, based on a series of characterization analysis, it could be determined that the increased surface area, enhanced spectral absorption and the fabrication of p-n heterojunction with the interface electric field were primarily responsible for the wonderful photocatalytic activities. Ultimately, the possible energy band transition after contact and photocatalytic mechanism were elucidated according to the ESR and Mott-Schottky results. It is predictable that our work will provide some inspiration for exploring other p-n heterojunctions with excellent performances.

Efficient design and construction of core-shell heterojunction is regarded as a promising strategy to promote interface electronic transfer for achieving enhanced photocatalytic hydrogen evolution and pollutant degradation. Thus, in this study, a novel core-shell CdIn2S4/Ta3N5 (CIS/TN) nanocomposite photocatalyst was designed and successfully fabricated via the facile in-situ hydrothermal process, where the CdIn2S4 nano-octahedra densely anchored on the surface of Ta3N5 nanoparticles to form the core-shell heterostructure. The as-prepared CIS/TN heterostructures all showed high dual-functional photocatalytic performances for H2 generation and Methyl Orange (MO) decomposition. Compared with pristine CdIn2S4, the photocatalytic activities of CIS/TN heterostructures were obviously enhanced and the sample CIS/TN-3 with the 3 wt% of Ta3N5 possessed the highest H2 production of 122.6 μmol·h−1·g−1, which was about 2.43 times as high as that of CdIn2S4 nano-octahedra. Also, it presented the optimal MO photodegradation efficiency (92.2%) and its rate constant was 2.79 times higher than that of pure CdIn2S4. The wonderful dual-functional photocatalytic performance could be attributed to the broad spectral adsorption region and efficient transfer of photoinduced charge carriers between the intimate heterogeneous interface, which would lead to the higher quantum yield and efficiency. The detailed charge transfer path and possible reaction mechanism were also proposed based on the results of trapping experiments and ESR analysis. Our research may provide a direct guidance for developing other highly-efficient Ta3N5-based core/shell heterostructure for energy conversion and environmental governance.

The development of highly efficient and multifunctional composite photocatalysts for both energy conversion and environmental governance has obtained great concerns. Here, a novel CdIn2S4/TiO2 (CIS/THS) hollow composite photocatalyst was firstly designed and synthesized via a facile in-situ growth process, where the CdIn2S4 nano-octahedra densely attached on the surface of TiO2 hollow spheres to form the unique hybrid heterostructure. The as-synthesized CIS/THS heterojunctions exhibit much superior photocatalytic activities for hydrogen evolution and Methyl Orange (MO) decomposition in comparison to pure CdIn2S4 and TiO2 hollow spheres. The experimental results display that the CIS/THS-3 sample with the 30 wt% of TiO2 presents the optimal photocatalytic H2 production efficiency and its generation rate is 3.38 and 2.56 times as high as those of pure TiO2 and CdIn2S4. Besides, the as-synthesized CIS/THS-3 hybrid also possesses the best MO photodegradation performance and its rate constant is 11.43 and 8.34 times higher than those of pure TiO2 and CdIn2S4. The enhanced photocatalytic activities can be assigned to the synergistic effect, optimized light-harvesting capacity and the formation of hybrid heterostructure for boosting interfacial charge transfer and separation. Furthermore, based on the trapping experiments and ESR analysis, the possible type-Ⅱ interface charge transport mechanism was also proposed. Our study may provide the direct guidance for constructing other hollow TiO2-based composite photocatalysts with superior photocatalytic water splitting and degradation performances.

The design and construction of efficient visible light responsive composite photocatalysts with intimate interfacial contacts in photocatalytic field have attracted huge interest. Herein, a double-shelled ZnIn 2 S 4 nanosheets/TiO 2 hollow composite single nanosphere (ZIS/TiO 2 ) was first fabricated by a facile hydrothermal process, where 2D ZnIn 2 S 4 nanosheets self-assembled on the external surface of TiO 2 hollow nanosphere to form the double-shelled hollow single sphere. The morphologies, structures, optical properties of as-prepared double-shelled ZIS/TiO 2 hollow nanospheres were characterized in detail. The photocatalytic activities of double-shelled ZIS/TiO 2 nanospheres for the photodegradations of Tetracycline hydrochloride, Levofloxacin and Rhodamine B under visible light irradiation have been investigated. Compared to pure TiO 2 and ZnIn 2 S 4, the obtained ZIS/TiO 2 samples have significantly improved photocatalytic performances. The most optimal photocatalytic activity of ZIS/TiO 2 -2 nanocomposite with 64 wt% ZnIn 2 S 4 nanosheets coated is observed, and its degradation rate constant is 2.32 and 2.14 times as high as those of pure TiO 2 and ZnIn 2 S 4 . The superior photocatalytic performance of ZIS/TiO 2 nanocomposite can be ascribed to its unique double shell hollow structure and the synergistic effect between ZnIn 2 S 4 and TiO 2 . Our result provides some guidance for designing novel morphologies of composite photocatalyst with good photocatalytic performance.

A simple impregnation–calcination method has been proposed to produce excellent photocatalytic Z-scheme Zn3(VO4)2 porous nanoflower/g-C3N4 nanosheet (ZV-CN) heterostructure photocatalyst. The optical, morphological and photocatalytical properties were investigated in details. Interestingly, after coupling Zn3(VO4)2 with g-C3N4, the hybrids exhibited the extended spectral response and obviously enhanced photocatalytic MB dye mineralization activity. Particularly, the high stable and reusable 5-ZV-CN photocatalyst possessed excellent photocatalytic performance (95.45%) for MB degradation as compared to g-C3N4 (57.66%) and Zn3(VO4)2 (36.71%), which could be attributed to the drastically improved separation efficiency of photoinduced carries, the stronger oxidation and reduction ability via direct Z-scheme transfer as well as the porous surfaces. This present work provides a new kind of g-C3N4 based Z-scheme heterojunctions with high photocatalytic activity.

This paper focuses on the dynamic energy management for Hybrid Electric Vehicles (HEV) based on driving pattern recognition. The hybrid electric system studied in this paper includes a one-way clutch, a multi-plate clutch and a planetary gear unit as the power coupling device in the architecture. The powertrain efficiency model is established by integrating the component level models for the engine, the battery and the Integrated Starter/Generator (ISG). The powertrain system efficiency has been analyzed at each operation mode, including electric driving mode, driving and charging mode, engine driving mode and hybrid driving mode. The mode switching schedule of HEV system has been designed based on static system efficiency. Adaptive control for hybrid electric vehicles under random driving cycles with battery life and fuel consumption as the main considerations has been optimized by particle swarm optimization algorithm (PSO). Furthermore, driving pattern recognition based on twenty typical reference cycles has been implemented using cluster analysis. Finally, the dynamic energy management strategy for the hybrid electric vehicle has been proposed based on driving pattern recognition. The simulation model of the HEV powertrain system has been established on Matlab/Simulink platform. Two energy management strategies under random driving condition have both been implemented in the study, one is knowledge-based and the other is based on driving pattern recognition. The model simulation results have validated the control strategy for the hybrid electric vehicle in this study in terms of drive pattern recognition and energy management optimization.