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Recently, the application of titanium dioxide (TiO2) in the context of the photoelectrochemical photocurrent switching (PEPS) effect has been extensively explored, offering significant potential for TiO2 materials in areas such as logic gates, biosensing, and communications. Ti ions exist in multiple oxidation states, with each state exhibiting different photoelectrochemical activities, playing a crucial role in regulating the PEPS effect. However, research in this area remains relatively scarce. In this study, we utilized a thermal annealing method to modulate the oxidation states of Ti ions in TiO2 nanofilms and investigated their respective PEPS effects. No bipolar behavior of the photocurrent was observed in untreated or low-temperature annealed amorphous TiO2 thin nanofilms, whereas clear bipolar behavior was evident in the high-temperature annealed rutile TiO2. This phenomenon was primarily attributed to the high activity of Ti3+ ions introduced by the phase transition, enabling photogenerated electrons to overcome the semiconductor–electrolyte potential barrier and participate in the reduction reaction within the solution. Furthermore, our research revealed a remarkable phenomenon where the potential barrier between high-temperature annealed rutile TiO2 nanofilms and the electrolyte is influenced by the wavelength of the incident light source, leading to a reversal in current polarity under 254 and 365 nm illumination. This effect was a result of the accumulation of photogenerated electrons at the semiconductor/electrolyte interface, creating an opposing built-in electric field that lowered the potential barrier between the semiconductor and electrolyte. Finally, we constructed externally biased tunable Boolean logic gates based on rutile TiO2 nanofilms, utilizing varying wavelengths of solar-blind ultraviolet light as input sources. This innovative approach offers a pathway toward achieving the multifunctional integration of optoelectronic devices in the post-Moore era. [ABSTRACT FROM AUTHOR]

Using atomistic empirical pseudopotentials, we have calculated the electronic structures of CdSe nanowires with a bulged area. The localized state wavefunctions and their binding energies are calculated, and their dependences on the bulged area shape are analyzed. We find that both the binding energy and the wavefunction localization strongly depend on the bulged area shape, with the most compact shape produces the largest binding energy and strongest wavefunction localization. We also find that the top of the valence band state has a weaker localization than the bottom of the conduction band state due to an effective mass anisotropy.

C27H25Cl2NO4, monoclinic, P21/n (no. 14), a = 18.9834(7) Å, b = 8.5683(3) Å, c = 30.4308(12) Å, β = 93.832(1)°, V = 4938.7(3) Å3, Z = 8, Rgt(F) = 0.0655, wRref(F2) = 0.2089, T = 296(2) K. [ABSTRACT FROM AUTHOR]

In this study, a design method of broadband low-frequency muffler based on NN method and Helmholtz resonators with helical necks is proposed, which ensures almost perfect ventilation and broadband sound insulation in the low- and medium-frequency range. First, the sound insulation performance of the muffler is improved by adding a helical structure at the port. The slit Helmholtz resonator with a helical structure is able to reduce the cross-sectional area of the resonator port and increase the contact area of thermal viscosity loss, thus reducing the peak frequency of sound insulation and increasing the sound energy loss. Using finite element analysis software, the structural transmission loss is simulated. At the same time, the neural network method is used to predict the combined structure, then, the combined structure can be designed quickly and reasonably to achieve the sound insulation of medium- and low-frequency broadband. Experimental and simulation results show that in the target range of 430 Hz–2220 Hz, the overall TL exceeds 30 dB and the maximum exceeds 60 dB. In addition, when a helical structure is added, the overall pipeline remains unchanged; and when a muffler is added on the basis, the perfect ventilation effect can be achieved. The proposed structural model and the idea of rapid design lay a great foundation for the design and optimization of broadband muffler. [ABSTRACT FROM AUTHOR]

In this work, electric properties of undoped and MoO3-doped 0.93Bi0.5Na0.5TiO3-0.07BaTiO3 ceramics (BNT-BT: x mol. % MoO3) are systematically studied. At room temperature, the optimum piezoelectric property (d33 = 177.0 pC/N) was observed in BNT-BT: 0.10Mo ceramics, with remanent polarization (Pr = 32.15 μC/cm2), electromechanical coupling coefficient (kt = 0.578, kp = 0.169, k31 = 0.180), and mechanical quality factor (Qm = 90.3). Mo doping was found to have a positive effect on the depolarization temperature Td, and k31 showed excellent thermal stability at BNT-BT: 0.05Mo ceramics. These findings confirm that Mo doping is an effective method to improve BNT-based lead-free ceramics. [ABSTRACT FROM AUTHOR]

In this article, KNNLT-BNT lead-free ceramics were prepared by the solid solution method to regulate the grain size and electrical properties by Mn-doped. The doped concentrations were 0.3, 0.4, and 0.5%. The surface structure of the ceramic was characterized, and the Mn-doped can improve the ceramic compactness. The internal structure of the ceramic was analyzed, with the increase of Mn-doped concentration, the (101) peak shifted to a lower angle, and the lattice is distorted. Finally, the electrical properties of the ceramic were characterized by the optical band gap and dielectric constant. Analysis results show that when the Mn-doped concentration is 0.5%, the electrical performance is the best, the grain size follows a normal distribution, and the band gap width is the narrotest 2.693 eV. [ABSTRACT FROM AUTHOR]

Fe‐doped ZnO ceramic nanofibers (CNFs) as specific structural features and unique properties synthesized by using electrospun technology. X‐ray diffraction disclosed the wurtzite phase, and the microscopy analysis by SEM revealed the formation uniform nanofibers with 400 nm in diameter. The UV–visible diffuse reflectance spectroscopy (DRS) was used to investigation the optical properties of the pristine and the various percentages Fe doped ZnO photocrystalysts. The photo‐reduction activities of photocatalyst were evaluated using methylene blue (MB) as organic contaminant irradiated with simulate solar light from xenon lamp. The photocatalytic results that 1% Fe‐doped ZnO CNFs exhibits efficient visible and UV light activity and excellent photo‐stability. The kinetic constant of MB degradation over 1% Fe‐doped ZnO is about 2.2 times higher than that over pure ZnO. The experiment demonstrated that the photodegradation efficiency of Fe‐doped ZnO was significantly higher than that of undoped ZnO. [ABSTRACT FROM AUTHOR]

The fabrication of all-solid-state planar on-chip microsupercapacitors with ultrahigh power characteristics was demonstrated by reduced graphene oxide and photolithography technology. In this paper, an ultrathin reduced graphene oxide film with a thickness of 8 nm was prepared by a modified spin coating method that makes the microsupercapacitors have higher power characteristics which appear in high conductivity and fast charge and discharge rates. The electrodes, with a width of 150 μm, are narrower than existing electrodes in the field and fabricated by photolithography. In terms of performance, these microsupercapacitors have an extremely short time constant which is 0.03 ms, a high power density which is 17.94 W cm−3, and an excellent cycle stability with a capacitance retention of 94.6% after 10 000 cycles. [ABSTRACT FROM AUTHOR]