Diode characteristics, piezo-photocatalytic antibiotic degradation and hydrogen production of Ce3+ doped ZnO nanostructures.

Piezo-photocatalysis of ZnO nanostructures had recently well attracted due to their exceptional potential in degrading the antibiotics and scalable hydrogen production. Here, we have synthesized the Ce3+ doped ZnO nanospheres in a facile wet chemical strategy. Dopant ions induced morphological evolution and optical bandgap tuning had observed in our experiment. Optical absorbance spectrum had confirmed the bandgap shortening occurs with Ce3+ doped ZnO specimens. The bandgap gap value had reduced to 2.82 eV from 3.05eV confirming the visible light responsivity of ZnO nano specimens. Obtained Zn(1-x)CexO nanospheres were utilized to fabricate the p-Si/n- Zn(1-x)CexO heterojunction diodes as well studied the improved electrical conductivity for the Ce3+ specimen-based diodes. Besides, ideality factor and barrier height values of the heterojunction diodes ZnO/p-Si, Zn0.99Ce0.01O/p-Si, Zn0.97Ce0.03O/p-Si, and Zn0.95Ce0.05O/p-Si are 15.97 & 0.43 eV, 15.47 & 0.44 eV, 8.02 & 0.46 eV and 5.21 & 0.47 eV, respectively. Direct sunlight assisted piezo-photocatalytic tetracycline (TC) degradation efficiency of ZnO, Zn0.99Ce0.01O, Zn0.97Ce0.03O, and Zn0.95Ce0.05O nanostructures respectively are 64%, 69%, 74% and 82%. We have produced the hydrogen quantity of 1234 µ mol h-1, 1490 µ mol h-1, 1750 µ mol h-1 and 1980 µ mol h-1 with 0%, 1%, 3% and 5% Ce3+ doped ZnO specimens under the direct sunlight assisted piezo-photocatalytic H2 production from H2S splitting.

Cobalt oxide coupled with graphitic carbon nitride composite heterojunction for efficient Z-scheme photocatalytic environmental pollutants degradation performance.

The Co3O4/g-C3N4 Z-scheme composite heterojunction has been effectively built in a facile sonication-assisted hydrothermal manner. The as-synthesized optimal 0.2 M Co3O4/g-C3N4 (GCO2) composite photocatalysts (PCs) revealed admirable degradation efficiency towards methyl orange (MO, 65.1%) and methylene blue (MB, 87.9%) organic pollutant compared with bare g-C3N4 within 210 min under light irradiation. Besides, the features of investigating structural, morphological and optical properties have evidence that the unique decoration effect of Co3O4 nanoparticles (NPs) on the g-C3N4 structure with intimate interface heterojunction of well-matched band structures noticeably facilitates the photo-generated charge transport/separation efficiency, reduces the recombination rates and widens the visible-light fascination which could advantageous to upgrading photocatalytic action with superior redox ability. Especially, the probable Z-scheme photocatalytic mechanism pathway is also elucidated in detail based on the quenching results. Hence, this work delivers a facile and hopeful candidate for contaminated water remediation via visible-light photocatalysis over the efficient g-C3N4-based catalysts.

Self-monitored and optically powered fiber-optic device for localized hyperthermia and controlled cell death in vitro.

Localized hyperthermia therapy involves heating a small volume of tissue in order to kill cancerous cells selectively and with limited damage to healthy cells and surrounding tissue. However, these features are only achievable through real-time control of the tissue temperature and heated volume, both of which are difficult to obtain with current heating systems and techniques. This work introduces an optical fiber-based active heater that acts both as a miniature heat source and as a thermometer. The heat-induced damage in the tissue is caused by the conductive heat transfer from the surface of the device, while the heat is generated in an absorptive coating on the fiber by near-infrared light redirected from the fiber core to the surface by a tilted fiber Bragg grating inscribed in the fiber core. Simultaneous monitoring of the reflection spectrum of the grating provides a measure of the local temperature. Localized temperature increases between 0°C and 100°C in 10 mm-long/5 mm-diameter cylindrical volumes are obtained with continuous-wave pump power levels up to 1.8 W. Computational and experimental results further indicate that the temperature rise and dimensions of the heated volume can be maintained at a nearly stable level determined by the input optical power.