Sonoelectrodeposition of poly(pyrrole) films: Electrochemical and morphological effects caused by the ultrasonic amplitude

Bidirectional Voltage Regulation for Integrated Photovoltachromic Device Based on P3HT-Electrochromic Unit and Perovskite/Organic Tandem Solar Cells

Integrated electrochromic devices powered by photovoltaic cells have evoked a lot of interest due to their promising commercial prospects. However, their application has been restricted by the voltage adaption between the self-powered voltage and the color-changing threshold voltage (Vt). Herein, a strategy of bidirectional voltage regulating is proposed to develop a novel stand-alone integrated photovoltachromic device (I-PVCD), which integrates perovskite/organic tandem solar cells (P/O-TSCs) to drive color-changing process of conjugated poly(3-hexylthiophene) (P3HT) films. To lower the driving-voltage of electrochromic layer, C60 is introduced to decrease the onset oxidation potential of P3HT film, and thus leading to a reduced Vt of 0.70 V benefiting from the enhanced highest occupied molecular orbital level and decreased charge transfer resistance from 67.46 to 49.89 Ω. Simultaneously, PBDB-T is utilized as the hole transport layer in the interconnecting layer of CsPbI2Br/PTB7-Th:IEICO-4F P/O-TSC to improve its open-circuit voltage (Voc) to 1.85 V. Under their synergetic merits, a I-PVCD with a wider self-adaptive voltage range is achieved. This device can undergo fast and reversible chromic transition from beautiful magenta to transparent only under the solar radiation, and demonstrates a coloration efficiency of 351.90 cm2 C-1 and a switching time of 2 s besides its excellent operating reliability.

Comparative Study of Corrosion Behavior of LPCVD-Ti0.17Al0.83N and PVD-Ti1−xAlxN Coatings

In the present work, a low-pressure chemical vapor deposition (LPCVD) Ti0.17Al0.83N and state-of-the-art arc ion plating PVD-Ti1−xAlxN (x = 0.25, 0.55, 0.60, 0.67) coatings were deposited on cemented carbide substrate. The morphological, structural, and electrochemical properties of LPCVD-Ti0.17Al0.83N and PVD-Ti1−xAlxN coatings were compared. The X-ray diffraction (XRD) results and scanning electron microscopy (SEM) images revealed that the LPCVD-Ti0.17Al0.83N coating had a face-centered cubic (fcc) structure, while presenting a crack-free surface morphology and a compressive residual stress of −131.9 MPa. The PVD coatings with a composition of x ≤ 0.60 had an fcc structure, while the PVD-Ti0.33Al0.67N coating consisted of fcc and w-AlN phases. The results of the electrochemical corrosion test showed that the LPCVD-Ti0.17Al0.83N coating had the lowest corrosion current density in a 3.5 wt.% NaCl solution. After a 20-day immersion corrosion test in a 5 mol/L HCl solution, the LPCVD-Ti0.17Al0.83N coating displayed higher stability than the PVD-Ti1−xAlxN coating. The results of electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) analysis revealed that more uniform and denser passivation film, as well as higher Al2O3 proportion in the Al2O3/TiO2 composite passive layer, led to the outstanding corrosion resistance of the LPCVD-Ti0.17Al0.83N coating.

In Situ Coupling of Ultrasound to Electro- and Photo-Deposition Methods for Materials Synthesis

This short review provides the current state-of-the-art of in situ coupling of ultrasound to chemical deposition methods. Synergetic action of ultrasound and light radiation or electrical fields may result in new powerful methodologies, which include sonophotodeposition and sonoelectrodeposition processes. The effect of ultrasound is explained on the basis of different physical mechanisms emerging from cavitation phenomenon. Some possible mechanisms of the interactions between ultrasound and photochemical and electrochemical processes are discussed here. The application of sonophotodeposition and sonoelectrodeposition as green energy sources in the syntheses of different nanomaterials is also reviewed.