Well-designed g-C_(3)N_(4)nanosheet incorporated Ag loaded Er_(0.05)La_(0.95)FeO_(3)heterojunctions for isoamyl alcohol detection

Because the volatile content of isoamyl alcohol increases sharply on the seventh day of wheat mildew infection,isoamyl alcohol can be used as an early biomarker of wheat mildew infection.Currently,only a few sensors for isoamyl alcohol detection have been reported,and these sensors still suffer from low sensitivity and poor moisture resistance.Herein,the isoamyl alcohol sensitivity of 5 at%Er@LaFeO_(3)(ELFO)was enhanced by loading Ag nanoparticles on the surface of the ELFO microspheres,while the optimal operating temperature was reduced.The moisture resistance of Ag/ELFO was improved by the incorporation of g-C_(3)N_(4)nanosheets(NSs)on the surface of Ag/ELFO through electrostatic self-assembly.Given the requirements for practical applications in grain granaries,the sensing behavior of a Ag/ELFO-based sensor incorporating g-C_(3)N_(4)NSs at 20%relative humidity(RH)was systematically studied,and the sensor demonstrated excellent repeatability,long-term stability,and superior selectivity(791 at 50 ppm)for isoamyl alcohol with a low limit of detection(LOD=75 ppb).Furthermore,the practical results obtained for wheat at different mildew stages further confirmed the potential of the g-C_(3)N_(4)/Ag/ELFO-based sensor for monitoring the early mildew stage of wheat.This work may offer guidance for enhancing the moisture resistance of gas-sensitive materials through the strategy of employing composite nanomaterials.

High-sensitive and fast MXene/silicon photodetector forsingle-pixel X-ray imaging

The demand for high-performance X-ray detectors leads to material innovationfor efficient photoelectric conversion and carrier transfer. However, currentX-ray detectors are often susceptible to chemical and irradiation instability,complex fabrication processes, hazardous components, and difficult compatibility.Here, we investigate a two-dimensional (2D) material with a relativelylow atomic number, Ti_(3)C_(2)T_(x) MXenes, and single crystal silicon for X-ray detectionand single-pixel imaging (SPI). We fabricate a Ti_(3)C_(2)T_(x) MXene/Si X-raydetector demonstrating remarkable optoelectronic performance. This detectorexhibits a sensitivity of 1.2 × 10^(7) μC Gyair^(-1) cm^(-2), a fast response speed with arise time of 31 μs, and an incredibly low detection limit of 2.85 nGyair s^(-1).These superior performances are attributed to the unique charge couplingbehavior under X-ray irradiation via intrinsic polaron formation. The deviceremains stable even after 50 continuous hours of high-dose X-ray irradiation.Our device fabrication process is compatible with silicon-based semiconductortechnology. Our work suggests new directions for eco-friendly X-ray detectorsand low-radiation imaging system.

Oriented electron tunneling transport in hierarchical Ag/SiO_(2)/TiO_(2) nanobowl arrays for plasmonic solar water splitting

Hierarchical Ag/SiO_(2)/TiO_(2) nanobowl(NB)arrays were fabricated for use as plasmonic photoanodes for solar-hydrogen conversion.The nanobowls had large pore size and were composed of an upper TiO_(2) nanoring and a lower TiO_(2) nanohole.A thin SiO_(2) inter-layer was introduced as an electron transmission channel to change the mechanism of hot electron transport.Simulations were performed to characterize the variation of electron concentration in Ag/SiO_(2)/TiO_(2) NB arrays,taking into account both the optical transition of photogenerated electrons,and electron tunneling.The multiphysics coupling function of COMSOL software provided the light source for optical transition of photogenerated electrons,and a Wentzel-Kramers-Brillouin model was employed to represent the tunneling.The results demonstrate that the TiO_(2) nanoring was a transporter,which transmitted electrons downward to the nanohole.The SiO_(2) layer replaces the Schottky barrier to become a bridge for tunneling of hot electrons in high-and low-energy states into TiO_(2).Moreover,the coverage of the SiO_(2) layer helped increase the light absorption of TiO_(2),it also reduced the near electric field coupling between Ag and TiO_(2).Accordingly,under AM 1.5 light irradiation,the photocurrent density and average hydrogen evolution rate of Ag/SiO_(2)/TiO_(2) were 1.8 and 2.2 times higher,respectively,than those of pure TiO_(2),implying far more efficient migration of carriers.