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Ferroelectric ceramic capacitors show great potential in pulse power devices for their fast charging-discharging characteristics and immense power density. As a relaxation ferroelectric material, Sr0.7Bi0.2TiO3 has the advantage of high energy storage efficiency. Nevertheless, its low breakdown strength limits its energy storage performance. Herein, Sr0.7Bi0.2Ti(1–1.25x)TaxO3 (SBT-T) ceramics were synthesized by introducing Ta2O5 with a broad bandgap. On the one hand, the B-site ion disorder enhanced the relaxor behavior of the SBT-T ceramics. On the other hand, the introduction of Ta boosted the impedance and activation energy of the SBT-T ceramics, thus significantly improving their breakdown strength. With the increase in Ta content, the critical electric fields of SBT-T ceramics were monotonically increased from 240 to 370 kV/cm (increased by 54%), and splendid Wrec = 2.33 J/cm3 and high η = 91.76% were achieved when x = 0.04 under 290 kV/cm. Additionally, the SBT-0.04T ceramics demonstrated excellent pulse charge–discharge speed (t0.9 of 81.69 ns) and power density (PD of 153.39 MW/cm3). This research revealed that Ta doping was an effective approach to strengthening breakdown strength, which might provide ideas for improving the energy storage performance of dielectric capacitors. [ABSTRACT FROM AUTHOR]

The light response range, reusability, and durability of photocatalyst are the key issues for its practical application. To address these problems, the C-doped TiO2/carbon nanofibrous (CTCNF) film with incorporation of C-doped TiO2 nanoparticles into carbon nanofibers was prepared by electrospinning and calcination (pre-oxidation and carbonization). All the obtained CTCNF films exhibited a promising light absorption in ultraviolet-visible region. With optimization of carbonization temperature, the CTCNF film carbonized at 800 °C (CTCNF-800) showed a strongest light absorption. Consequently, the CTCNF-800 possessed a highest photocatalytic degradation efficiency of 94.2% for degradation of rhodamine B. In addition, the CTCNF-800 possessed excellent flexibility and deserved mechanical strength, and hence, the CTCNF-800 could be easily segregated from solution and recycled. Satisfyingly, its degradation efficiency still exceeded 92% after using for six cycles, implying that the CTCNF had excellent reusability and well stability. Besides, the degradation efficiency was over 90% after the CTCNF-800 kept in air without illumination for 1 year, indicating its outstanding durability. The CTCNF film photocatalyst demonstrates tremendous potential in practical application for purification of wastewater. [ABSTRACT FROM AUTHOR]

In this paper, g-C3N4/SnO2:Sb composite photocatalysts were fabricated by in situ loading Sb-doped SnO2 (SnO2:Sb) nanoparticles on graphitic carbon nitride (g-C3N4) nanosheets via a facile hydrothermal method. The synthesized g-C3N4/SnO2:Sb composites delivered enhanced visible light photocatalytic performance for degradation of rhodamine B in comparison with g-C3N4/SnO2 composites without doping Sb. Various techniques including XRD, SEM, TEM, FTIR, XPS, PL and electrochemical method were employed to demonstrate the successful fabrication of g-C3N4/SnO2:Sb composite and to investigate the enhanced mechanism of photocatalytic activity. The improvement of visible light absorption and the promotion of separation efficiency and interfacial transfer of photogenerated carriers induced by Sb doping were responsible for the enhancement of photocatalytic activity. This study provides a simple and convenient method to synthesize a visible light responsive catalyst with promising performance for the potential application in environmental protection. [ABSTRACT FROM AUTHOR]

To improve the desulfurization performance of sorbents at a low cost, modified semicoke-supported zinc oxide sorbents were prepared for hot coal gas by calcining the precursors using microwave and conventional heating. The desulfurization performances of these sorbents were evaluated over a fixed-bed reactor. The effects of microwave-assisted calcination temperature and time on the properties of sorbents were also investigated. These sorbents were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and nitrogen adsorption. The results show that the sorbents calcined by microwave exhibited a much higher sorbent utilization and desulfurization efficiency than those heated by conventional method. Compared to conventional heating, even and rapid heating of microwave led to smaller crystal size and better dispersion of active species. The Brunauer-Emmett-Teller results confirm that microwave irradiation modified the microstructure improved the pore structure (an increase in the specific surface area and pore volume), thus facilitating the gas-solid interactions during the desulfurization processes. A higher concentration of elements Zn and O was observed on the surface of sorbents by XPS analysis, facilitating the reaction of active species with HS. The performance of the sorbents heated by microwave irradiation appeared to be stable over multiple sulfidation-regeneration cycles. [ABSTRACT FROM AUTHOR]